A Comprehensive Guide to Gain Staging, Recording, Mixing, and Mastering Levels for Classical Guitarists
Part I - Gain Staging & Recording Recording
As we, classical guitarists, have ventured into the world of recording, we've faced the intriguing challenge of capturing our instrument's perfect sound. After meticulously learning about different microphones, mastering the art of microphone arrays, and optimizing our room for the ideal recording tone, we often feel ready to immortalize our masterpiece. Yet, beneath this readiness lies a vast universe of elements that we need to fine-tune to achieve an optimal recording. Among these, understanding gain staging, recording levels, mixing, and mastering levels is crucial.
While there's a plethora of information available on the internet, it can often feel like trying to find our way through an intricate maze, riddled with confusing technical jargon and conflicting advice. In light of this, I've decided to consolidate my personal insights, specific tips, and favorite tools into this comprehensive guide. My aim is to shed some light on these crucial aspects and assist you in capturing and polishing your classical guitar recordings to perfection.
dB Trivia
But first, we have to familiarize ourselves with decibels or dB. These logarithmic units are used to measure the intensity of audio signals. The world of digital audio can be treacherous if you're not careful - one misstep could lead to clipping or distortion, which occurs when the audio signal exceeds 0 dBFS (decibels relative to full scale). Attention to detail is pivotal.
Recording Levels & Gain Staging: Laying the Foundation for a Great Recording
The journey to a great recording begins with understanding gain staging. Gain staging is a process that ensures a clean, distortion-free recording while leaving enough breathing room for further processing during post-production. This involves setting optimal levels of audio signals at each stage of your recording chain. In the context of home studios, this often involves just your instrument, an audio interface, and perhaps some ITB (In The Box) processing.
However, even in this simplified chain, ensuring good gain staging remains crucial. This starts with the sound of your instrument in the room. You'll need to ensure your guitar's sound is clear, resonant, and free from any unwanted noise or interference. Careful placement of the microphones is also key.
Each microphone and each placement will give a different color and character to your recording. When setting up my microphones, I experiment with different placements and distances. Finding the sweet spot is an art - it should capture the guitar's natural tone while minimizing room noise. Adjusting the distance and angle of your microphones can help control not only the tone but also the levels: too close and the sound might be overly loud or boomy; too far and the signal could be weak, leading to a noise-prone recording when amplified. Have a look at my Stereo Microphone Techniques for the Classical Guitar guide..
The next step in the chain is the audio interface. This is where the acoustic energy, the sound waves your guitar produces and your microphones capture, are converted into digital signals your computer can understand.
Your audio interface typically has preamps which amplify the microphone's signal to a level suitable for the Analog to Digital Converter (ADC). The gain knob on your interface controls this amplification. It's crucial to find the right balance here: a signal that's too weak may introduce noise when you try to increase the volume later, while a signal that's too strong risks clipping, distorting your guitar's natural sound.
Once gain staging is properly set, the next crucial part of the process is managing your recording levels. Recording levels refer to the strength or amplitude of the audio signals being recorded in your DAW. In other words, it’s about how loud the recorded audio will be.
For classical guitar, I aim for an average level (or RMS level) around -18 dBFS to -12 dBFS, with peaks not exceeding -6 dBFS. This ensures a healthy signal level without risking distortion or clipping. These values might not mean much if you're just starting out, but understanding them and using a metering tool to monitor your levels will make a big difference in the quality of your recordings.
For those of you who, like me, prefer to use an external preamp along with a separate ADC, the gain staging process involves an additional step but the principle remains the same. Using an external preamp like the AEA TRP2 or SPL Crescendo duo, allows for even more control over the tonal characteristics and the level of the signal coming from your microphones.
Once the signal is conditioned by the preamp, it then goes into a separate ADC, such as the RME ADI-2 Pro FS in my case, which converts the analog signal into digital. Adjusting the input level on the ADC is equally crucial as on the audio interface's preamp for those who use an integrated solution. The goal is the same - ensuring a healthy signal level without risking distortion or clipping, which for me is around -18 dBFS to -12 dBFS RMS, with peaks not exceeding -6 dBFS.
This might seem like an extra layer of complexity, but in my experience, the flexibility and control provided by separate high-quality preamps and ADCs can lead to even better results, and it's worth considering if you're serious about recording.
To sum up, good gain staging for a classical guitar recording involves capturing a clean signal from your guitar, through the air, into your microphones, then into your audio interface, and finally into your DAW. Each step requires careful attention, but with practice and patience, the results can be immensely rewarding.
Additional Tips for Optimal Gain Staging:
I mainly use Vovox Sonorous and Sommer Epilogue cables for a peace of mind
Starting with a Clean Signal: The quest for the perfect recording begins long before hitting the record button. I ensure that my guitar is properly set up and my strings are in good condition to minimize extraneous noise and to allow for effecient dynamics.
High-Quality Cables: Cables can often be overlooked, but they are a critical part of the signal chain. Investing in high-quality cables can prevent unwanted noise and interference in the signal.
Room Acoustics: The room's acoustics can impact the recording significantly. A quiet and sonically balanced room can help ensure a clean, high-quality recording.
Monitoring the Signal Chain: Vigilance is key throughout the recording process. By continuously monitoring the levels throughout my recording chain, I can prevent unexpected overloads or distortions and ensure the best quality recording.
Using Metering Tools for Precision
Youlean Loudness Meter is an essential tool
For those of us who want to be precise with our levels, I highly recommend using metering tools. One of my favorite tools is the Youlean Loudness Meter. This handy software allows me to monitor not only the loudness of my recording but also the dynamic range. The free version is good enough for most cases, and you can support the developers by purchasing the pro version which provides some additional features.
Maintaining Dynamic Control
Classical guitar's essence lies in its subtleties and nuances. Dynamics - the interplay between the quietest and loudest notes, crescendos, decrescendos - bring the music to life, allowing your listeners to connect more deeply.
When setting my recording levels, I always leave ample headroom for these dynamics, striking a balance so that the louder sections don't cause distortion or clipping and the quieter parts remain clear and noise-free. Remember, amplifying a quiet, clean recording is always preferable to fixing a loud, distorted one.
Additionally, transient details - quick, high-energy moments - require careful attention to avoid distortion or getting lost in the mix. Proper recording levels ensure these moments are accurately captured, adding to the richness of the final recording.
Striking the Right Tone
In conclusion, understanding and managing recording levels, along with proper gain staging, can make a significant difference in capturing a perfect performance. It can be the difference between a recording that sounds amateur and one that stands up to professional scrutiny. With careful attention to detail, patience, and practice, you'll be on your way to making recordings that you can be proud of.
Stay tuned for Part II of this series, where we'll dive deeper into the realm of audio recording as we explore the importance of levels in the post-production stages - mixing and mastering. This is where your carefully recorded tracks are polished into a cohesive, balanced, and compelling final product. Until then, happy recording!
A Beginner's Guide to Home Recording for Classical Guitarists
Home recording technology has come a long way in recent years, and it's now easier than ever for classical guitarists to record high-quality audio from the comfort of their own home. If you are a classical guitarist looking to record your music at home, you may be wondering where to start. In this beginner's guide, I will go over the essential tools and techniques you'll need to get started with home recording for classical guitarists. From choosing the right microphone and recording software to setting up a recording space and editing and producing your tracks, I will cover everything you need to know.
Choosing the Right Equipment
The first step in setting up a home recording studio for classical guitar is choosing the right equipment. There are a few key pieces of equipment that every home recording studio should have:
Microphones: A good pair of microphones is essential for recording the classical guitar. There are many different types of microphones to choose from, each with unique characteristics. I often like to employ large diaphragm condensers for their low self-noise.
Read the buyer's guide on the Best Microphones for Classical Guitar.
Audio interface: An audio interface is a device that connects your microphones to your computer, allowing you to record audio digitally. Besides, an audio interface allows you to connect your headphones and studio monitors.
Read the buyer's guide on the Best Audio Interfaces for Classical Guitar.
Studio Monitors: Studio monitors are specialized speakers that are designed for use in recording studios. They differ from regular home speakers in that they have a relatively flat frequency response without boosting or attenuating any particular frequency. Studio Monitors are ideal for mixing and mastering music, as they allow you to hear the true sound of your recordings.
Read the buyer's guide on the Best Studio Monitors for Classical Guitar.
Headphones: Headphones are an important part of any home recording setup, as they allow you to hear all the nuances in your playing and recordings. I prefer open headphones for mixing, editing and music listening, while closed headphones are necessary if you want to do overdubs.
Setting up a Recording Space
Once you have the necessary equipment, the next step is to set up a recording space that will allow you to produce high-quality audio. Here are a few things to consider:
Acoustics: The acoustics of your recording space will have an immense impact on the sound of your recordings. A room with decent acoustics will produce a balanced and natural sound, while a room with poor acoustics can produce a boomy sound and introduce flutter echo to your recordings. To improve the acoustics of your recording space, you can use acoustic treatment products such as acoustic panels, bass traps and diffusers to absorb or diffuse sound waves.
If you are on a tight budget, you can read my post on Three Ways to Improve your Recording Space Without Spending Any Money.
Organization: Keep your recording space organized and ready to use at any time. This means having all your equipment in position and easy reach, so you don't have to spend time searching for things when you want to record. Furthermore, a cluttered and disorganized space can be distracting and make it difficult to focus on your playing. By setting up your room in a functional and organized way, you'll be able to focus on your playing and create better recordings.
Lighting: Good lighting will set the mood and create a comfortable practising recording environment. Natural light is usually the best choice, but if you don't have access to natural light, you can use artificial lighting to create a similar effect.
Getting Started with Recording Software
Once you have your equipment and recording space set up, the next step is to choose recording software. There are many different options available, ranging from free software with basic features to professional-grade software with advanced capabilities. Some popular DAW (Digital Audio Workstations) for recording classical guitar include:
Audacity is a free, open-source recording software popular with many classical guitarists. It offers a range of basic recording and editing features and is easy to use especially for beginners.
Apple GarageBand is a digital audio workstation that comes pre-installed on many Apple computers. It offers a range of basic recording and editing features and is suitable for beginners.
Apple Logic Pro is a professional-grade recording software widely used by music producers. It offers a wide range of advanced features and includes the most complete library of virtual instruments and a comprehensive set of plugin effects of any DAW.
Steinberg Cubase is another professional-grade recording software and a great alternative to Logic Pro if you are a Windows user. Cubase Elements is powerful enough for most classical guitarist applications and is affordable for those just getting started on recording.
Recording Techniques
Once you have your equipment and software set up, you are out of excuses; it's time to start recording! Here are a few tips for achieving the best sound from your classical guitar recordings:
Experiment with microphone placement: The position of the microphones relative to the guitar will have a huge impact on the sound of your recordings.
For a detailed description of various microphone techniques, read my post on Stereo Microphone Techniques for the Classical Guitar.
Set up the gain on your audio interface: The gain control on your audio interface determines the level at which your guitar is recorded. Set the gain to a level that avoids clipping (distortion) or a weak signal. Set the peaks (loudest parts) to reach around at around -6dB, so that you'll have plenty of headroom.
Have the right mindset for recording: An often overlooked aspect of the recording is the mindset and mood you bring to the recording. Be relaxed and focused when recording, so that you can capture the best performance possible. Take breaks as needed to ensure that you are feeling fresh and energized.
For more suggestions, read my post on 5+1 Things You Should Do Before You Press the RECORD Button, from the perspective of a Classical Guitarist.
Editing and Producing Your Recordings
Once you've recorded your classical guitar tracks, the next step is to edit and produce your recordings to create a professional-sounding final result. Here are a few things to consider:
Be conservative with editing: Editing audio has become pretty simple, but too much editing makes your recordings end up sounding lifeless.
Use plugin effects wisely: While it's necessary to use EQ and Reverb plugins to fine-tune your recorded sound, create the right mood for your music, and enhance the sound of your tracks. Try not to overprocess the recording. Aim for a natural sound for your solo classical guitar music. For further information on plugins, read my post Three Most Essential Plugins for the Classical Guitar.
Set the levels correctly: Make sure that the volume of your music is loud enough but doesn't clip (distort) the outputs. Leaving about 1 dB of headroom is a good practice.
Exporting your music: When you're happy with your produced recordings, it's time to export them as a final audio file. Make sure to save your tracks in a high-quality format, such as WAV or AIFF, to preserve the sound quality of your recordings.
Conclusion
In conclusion, recording your music at home can be a rewarding and fulfilling experience, and it's easier than ever to get started with the right equipment and software. By following the tips and techniques outlined in this guide, you'll be well on your way to creating recordings you can be proud of.
5+1 Things You Should Do Before You Press the RECORD Button, from the perspective of a Classical Guitarist
The expeditious progress of technology since the dawn of the millennia has allowed musicians to be more self-sufficient than ever before. We can record, produce, and distribute our music without ever having to leave the house. Concert guitarists have always been masters of the art of independence; we perform solo most of the time, use only our instruments always, and are responsible for keeping them fit (string changes, tuning, cleaning, etc.). It comes with no surprise that guitarists have jumped the wagon of self-recording. Besides not needing much gear-wise, a couple of microphones, an audio interface, some headphones, and the recording setup is complete.
Managing all these duties is hard enough. On top, there is also the infamous red light syndrome that haunts musicians. It sometimes seems that the weight of this endeavour is too high to overcome. Discipline, dedication, and a good routine are prerequisites. In this post, we will not discuss the best microphones or plugins; I want to prepare you rather for the recording date with a few easy-to-follow suggestions to ensure that you will put your best performance on tape.
1. Have a plan
It is always a good practice to write down what you want to record and how your plan to go about it. If you are going to record multiple pieces, will you record several takes of each piece, or will you play the whole program several times? What is the order? What is the purpose of the recording? Documenting and archiving, or an upcoming album?
Make a plan. Then follow it, or don't. It is okay to change it as it is beneficial to remain flexible. Au contraire, without one, to begin with, it can quickly get too chaotic.
2. Setup in advance
Switching between putting on the performer, engineer, and sometimes even the videographer hats is not to be taken lightheartedly. The different tasks not only require respective skills, they also demand enough time to fine-tune all the details. Anticipate for quite a few trials until you have configured everything to taste. Going back and forth between setting up microphones, camera angles, and playing bits of music for the tests, can quickly wear you down. Therefore, if possible, set up everything the day before, thus on the recording day, you can focus only on the performance.
If this is not an option, reevaluate the length and goals of the recording session and add the necessary setup time. And before you jump into the recording, make sure to take a break. You will need a few moments to recenter yourself. Try to relax, get mentally prepared for the mission: to record your masterpiece.
3. Be prepared
Unless you are recording to document your progress, you will need to know your pieces inside out. The choreography of your hands should be practised to perfection and beyond. Allow your body to move with the pace of the music; freely, effortlessly. Study each element of the score meticulously, and memorise it if you can. Know how you articulate every phrase, each voice, how long is the fermata on the 10th measure, and express the difference between P and PP in each section. Be diligent. Again, allow for the unexpected. While playing, the piece might want to lead you to a different place; embrace it. Follow your instincts. But, start with the confidence of control.
4. Establish a routine that gets you in the zone
I could argue that recording should not be too casual, much like preparing and giving a recital. Depending on your goals and time, though, sometimes one has to squeeze a few recording moments into a rather busy schedule. Getting motivated and focused can get tricky under such circumstances. Besides, not every day is the same, so we are not always as inspired.
Observe and explore a few mechanisms to assist in getting in the zone quicker. Weather is meditation, fasting, listening to music, or pouring caffeine into your bloodstream, only you can decide. Find out what works for your lifestyle and establish a routine around it. Preferably, you should find a few alternative options.
5. Do not compare yourself
We do not live in a bubble, and neither does our art. We evaluate our efforts in context. Listen to your favourite recordings, and get inspired. Take notes on the performance subtleties, and try to imitate aspects of it in your practising. But, you must forget everything at some point. On the day of the recording, it is just you and your guitar; no time for self-doubt. So, be yourself, and allow the things that make you unique to manifest themselves. There is no other way to do it anyway.
Bonus - If you are recording on location, make a list, and write down all the essential gear you need to have with you. Do not forget the extra cables and batteries, SD cards, some tape and a Swiss army knife. A faulty cable or missing a 3/4" adapter can be a reason to end the session prematurely. Embarrassingly.
Closing Thoughts
Whether you are recording for professional purposes or yourself, remember to enjoy each and every part. If you follow the above guidelines, chances are that you will go home with a fantastic recording. If not, there is always another day, a second chance to conquer the session. After all, the path to greatness is always in constant dispute.
Best Type of Microphone for Recording the Classical Guitar
One of the most usual questions I get asked is which microphone is the best for capturing the classical guitar, but as with all deep questions in life, I'm afraid there is no simple answer. Our guitars, nails as well as playing techniques differ vastly. Besides, our rooms have unique properties, and of course, our tastes vary. Another decisive factor is our listening environments, but that's a subject for another day.
I've written on Classical Guitar Tones extensively about the different microphones, brands and models. If you have been here for a while, you've seen me test all sorts of microphones, entry-level to high-end. In this article, I take a step back and present my thoughts on the different types of microphones, their strengths and weaknesses. Plus some words on the different polar patterns.
On being passive
Ribbon microphones have a relatively simple design with no active circuitry and use a thin metal ribbon suspended in a magnetic field. Most ribbon designs hear sound bi-directionally and produce natural and complex recordings. They have the reputation of being fragile and need careful handling and storage.
Dynamic microphones are similar to ribbons as both capture sound by magnetic induction. In contrast, they are very robust, resistant to moisture, and have low sensitivity. In practice, they offer no real asset in classical guitar recordings as their advantages benefit mainly on-stage use and capturing of loud sources.
For the most part, I don't get along well with ribbon or dynamic microphones, mainly because of their sensitivity or lack of. I often play soft passages or employ silence in my music, and with passive microphones, one has to crank the gain on the preamps to get sufficient levels, resulting in unwanted noise. After all, the classical guitar is a soft and delicate instrument, and no matter which preamps you use, it is impossible to get noiseless classical guitar recordings with passive microphones.
Ribbon microphones are also quite forgiving to the various mechanical "non-musical" noises, such as nail and fretting sounds. And this is why some people love them, especially on harsher and louder instruments and a less subtle repertoire. But, I find the response of most but the finest ribbon microphones, principally with the thinnest ribbons (some Royer, AEA, and Samar makes come to mind), quite sluggish.
Phantom power required
Nowadays, there are a plethora of active ribbon microphones, purposed for capturing softer sources and being less dependent on the preamp choice. These tend to work better with classical guitar. Yet, even high-end active ribbon microphones are far from being noiseless. I understand that for some people noise is a nonissue, but for me, it is a distracting element. I like deep blacks and hate when the softer parts or rests are being washed away by preamp hiss.
Also, the figure-eight polar pattern found in most ribbons makes them less than ideal for many recording situations. They do work nicely as a side microphone in an M/S stereo array.
Capacitors move the (recording) world
Condenser microphones require a power source to function and generally produce a high-quality audio signal mainly due to the small mass of the capsule. They can capture on tape utmost detail, sometimes even too much of it, and are the most used transducers in recording sessions and concert halls.
Most of the classic designs have been either tube or transformer equipped condensers, but with the dominance of digital recording, transformerless solid-state condensers have increasingly gained popularity in classical recordings for their additional clarity and lower self-noise.
Size matters
Condenser microphones are categorized by the size of their diaphragm and come in two main types: small-diaphragm, like most Schoeps' and the Neumann KM184, and large-diaphragm, like the Neumann U87 and AKG C414.
So, which one is better for the classical guitar, you may ask? Not so fast. Again, the answer is not straightforward.
Let's talk first about their differences.
Small diaphragm condensers are usually more accurate, with a faster transient response and superior off-axis response. They are also smaller and lighter, so they are easier to carry, besides being visually unobtrusive. The latter is a decisive factor in why SDCs dominate the concert world.
Paying audiences generally don't enjoy seeing a stage the musicians surrounded by several dozens of microphones and bulky heavy-duty stands to support them. Neumann, Schoeps and DPA provide small-diaphragm condenser systems with every possible polar response and mounting option a classical sound engineer might on location.
Polar patterns say more than you think
The downsides of using SDC's on a classical guitar, especially at home, are only a few but nontrivial. Small-diaphragm condensers are tuned for specific roles. Directional microphones are either purposed for close spots on soloists, used in combination with a stereo array at some distance, or for the main pickup and thus are tuned to compensate for the high-end frequency loss that occurs. The result, when used inappropriately, is either a poor low-end response or hyperrealistic recordings with exaggerated high-end. In other words, they can easily sound thin and harsh.
On the other hand, SDCs with an omnidirectional response (the real microphones), especially those that have been tuned for the free field, offer an optimal response at both ends of the spectrum. Additionally, they provide greater flexibility in positioning owing to the absence of proximity side-effects but become a challenge to use in non-treated rooms that universally suffer from early reflections and standing waves.
Microphones with wide- or sub-cardioid polar characteristics come to close the gap, with a better low-end response than their cardioid cousins, some room rejection, and sometimes less pronounced high-end. Unfortunately, small-diaphragm cardioids with such polar patterns are rare, and except for the bargain Line Audio CM3 / CM4, they are always on the expensive side.
So, where does the good old large-diaphragm condenser fit?
Generally speaking, LDC's suffer from a pronounced proximity effect, transient smoothing and suboptimal off-axis colouration. In addition, they require sturdier stands, are more difficult to position due to their size and weight, and can be quite visually intrusive in videos.
All these intricacies cannot be good, right? Moreover, excellent sounding large-diaphragm condensers suitable for the classical guitar are quite rare and expensive, as most LDC's are targeted for vocal pickup.
Any advantages?
As I wrote above, noise on a recording can be distracting. The smaller the size of the capsule, the greater the self-noise of condensers. Tube and transformer-based microphones are also subject to higher noise levels. Therefore, transformerless large-diaphragm condensers have lower noise to signal ratios, with several Gefell, Austrian Audio, and Neumann models reaching nonexistent self-noise figures.
Likewise, many universal studio LDC's grant additional flexibility, as they bring multiple polar patterns, removing the need to own or carry multiple microphones or capsules on a session. With a modern microphone, like the excellent and most versatile Austrian Audio OC818, you can not only choose on the fly between any possible polar pattern, but you can also do it long after the recording has been completed.
Here is my recording of Debussy’s Prelude VIII. Recorded on location with a pair of Austrian Audio OC818s.
Let's proceed to checkout.
One can make a good recording with any decent microphone, some experimentation and post-production skills to boot. There are no excuses for bad recordings in 2022.
On a budget, neither ribbon nor large-diaphragm condenser microphones of decent quality can be found as cheaper offerings are made either for a vintage vibe or vocalists in mind. Line Audio's small-diaphragm condensers are the undenied kings of the entry-level recording setup.
When searching for a high-end classical guitar recording setup to capture a world-class guitarist with a magnificent guitar in an excellent sounding room, a pair of exceptional and well-positioned omnidirectional or somewhat directional condenser microphones is hard to beat. DPA, Gefell, Austrian Audio and several high-end Neumann condensers come to mind. In such a scenario, the size of the diaphragm is incidental. With less ideal conditions, even high-end SDC's on a solo classical guitar, be it directional or not, can expose flaws and produce unattractive recordings.
To conclude, in most situations I favour large-diaphragm condenser microphones for their inherent sound qualities and noiseless behaviour. First-class LDCs can produce a luxurious recording and provide a pleasant listening experience. I also like how they look on videos; unapologetic, proud and predominant, almost commanding. With that said, the realism that some of the best SDCs treat the listener when every element is exemplary can be breathtaking.
Perhaps it is more advantageous to bring together small- and large-diaphragm condensers in an elaborate three- or four-microphone array.
Stereo Microphone Techniques for the Classical Guitar
Stereo recording is the technique that involves two microphones that due to the captures the time differences of sound waves coming from a source, which gives depth and space to the recording. Similar to how our ears and brains record and process sound.
The Classical Guitar, albeit small, is an instrument with a complex sound and subtle peculiarities; and as such, it sounds better when is captured in stereo. Various stereo recording techniques have been developed since the early 1940s; each with distinct advantages and disadvantages.
If you ask, which is the best microphone technique for capturing the classical guitar in stereo, I'm afraid that the answer is not so simple. Room size, acoustics, the instrument, and the purpose of the recording, play a significant role; as well as our individual preferences.
In this article, I describe the most common stereo techniques from the point of you of a classical guitar recordist. I discuss their strengths and weaknesses, as well as prefered uses for each setup.
Note: This article is a work in progress; X/Y, M/S, and NOS setups will be added in the following weeks.
Spaced Pair Setups
AB Stereo
AB Stereo Array
The AB Stereo recording technique is based on a pair of spaced Directional or Omnidirectional microphones and provides in a pleasing and accurate capture with useful spatial information.
For home recordings, AB Stereo is one of the best options as it is easy to implement and get a consistent sound. A pair of Cardioids is usually preferred as they can successfully attenuate the room ambience.
Omnidirectional microphones capture the true low-end of the instrument though and have no proximity effect. You can position them closer to the source in a small room, or further away if the acoustics allow.
Application
Use a (minimum) distance of 20cm between the microphones for the most natural result. You can use a greater width, as the distance from the instrument increases, for a wider capture. I prefer a width between 30 and 40cm, for small/medium rooms, and up to 60cm for large halls.
If you position the AB Setup close to the guitar, you should avoid placing any microphone opposite to the soundhole, to prevent boominess. A microphone on each side of the soundhole will give the most balanced sound, off-axis towards the fretboard for more articulation or opposite of the bridge for a fuller sound.
The microphones are most commonly parallel to each other; but, since most microphones show a degree high-end directivity, we can fine-tune their response by angling them on the horizontal plane. If you aim them slightly outwards, you can attenuate some of the unpleasing mechanical noises of the guitar (fretting noises, squeaking, nails, etc.) You can also angle them slightly inwards to reject some of the room reflections.
The directional information as captured by an AB Stereo is not as accurate as of the coincident and near-coincident setups. This attribute can be an advantage if the performer moves a lot and assists in avoiding off-balanced results. I hardly ever pan the channels hard left and right, to preserve the integrity of the central image of the classical guitar.
The biggest drawback of the AB Stereo is its leaser compatibility with MONO playback (for example, a youtube video played on a smartphone); as a result, comb-filtering may be introduced.
Suitable Polar Patterns: Omni, Cardioid
Advantages
Easy implementation
Pleasing sound
Useful spatial information
Control of room ambience
Disadvantages
Playback in MONO may introduce comb filtering
Not the most accurate directional information
And here is a real-world example of the use of AB Stereo on Classical Guitar in a professional setting. I used a pair of Austrian Audio OC818 microphones set in a Custom Polar Pattern that combines the best of Cardioid and Omni qualities. The spacing of the microphones is 26cm. The goal was to capture the pure tone of my Angela Walter guitar together with the incredible sounding main hall of the Musikbrauerei in Berlin.
Near Coincident Setups
ORTF Stereo Technique
ORTF Stereo Array
Developed in the 1960s by the Office de Radiodiffusion Télévision Française, the ORTF is a stereo microphone configuration that with the use of two near coincident Cardioid microphones mimics the human ears.
The spacing of 17cm and 110° angle emulate respectively the distance between our ears and the shadow effect of the human head. The result is a realistic depiction of the sound field, both in directional and spatial areas, as well as a reasonable Mono compatibility.
Application
A pair of first-order Cardioid condensers is required for a proper ORTS, 17cm between the capsules and 110° angle. Other directional patterns can be used with respective changes in the width; for example, Schoeps suggests a distance of 21cm for the MK22 Open Cardioid capsules. You can also adjust slightly both the spacing and angle for the best sound.
The most critical aspect of ORTF is to balance the direct and diffuse sounds, as there is not much you can do in post-production afterwards. As always a minimum distance of 50cm is advised to avoid boominess, but I have had better results with a distance of 80cm to 110cm. At greater distances, a low-end boost might be required to compensate for the loss of low-end of directional microphones.
The ORTF main application is for large-scale sources, like orchestras and choirs. If positioned in a close distance, you might experience loss of focus with a perceived hole in the centre.
Consequently, depending on the room acoustics, the ORTF stereo array may be proved problematic in a home recording setting. As you might either have to place the microphones further away from the instrument, capturing the unattractive ambience of a small room, or suffer a smeary sound if you position the array closer.
Suitable Polar Patterns: Cardioid
Advantages
Realistic stereo field
Reasonable Mono compatibility
Disadvantages
Perceived Hole in the middle and loss of focus if positioned close to the source
Coda
Distance
The distance of the microphones to the source depends purely on the room size, the instrument, and the setup. As a rule of thumb, keep it smaller than that of the microphones to the front and side-walls. But never closer than 50cm.
Directional microphones have a sweet spot where the proximity effect eliminates, and the low-end frequency response becomes linear. If the microphones are not in the ideal position, you might need to apply a Low-Shelf EQ (boost or cut). Omnidirectional microphones have a better low-end response regardless of the distance but capture sound from all directions. So, be careful not to end up with an overly roomy recording.
Height
Most classical guitarists angle their guitars somewhat upwards to push the sound further back (and fill a concert hall). Correspondingly, the height of the microphones depends mainly on the distance to the guitar. The closer they are to the instrument the lower they need to be. If you place the microphones further away from the guitar, they need to be higher to retain definition and accuracy.
The sound travels as an impulse rather than a beam though, so there is some room for experimentation. If you prefer a fuller sound, you can position the microphones slightly lower. Contrarily, you can increase the clarity if you put the microphones higher. Use your ears and taste.
Vertical Angle
You can also exploit microphone angles in the vertical plane; you can increase clarity if they are on-axis with the top of the guitar, or aim them at a higher point to attenuate some of the high-end and undesired mechanical noises from the strings and nails.
About the Samples
Austrian Audio OC818 and OC18
I recorded all the examples with a pair of Austrian Audio OC818. I choose the OC818 for their clear sound, low self-noise, and multi-pattern options. The height of the microphones was 103cm (centre of the capsule), and the distance from the guitar was 90cm.
The signal chain was an AEA TRP2 Microphone Preamp into an RME ADI-2 Pro FS ADDA Converter.
I didn't provide samples in other distances as they would only give cues about my room and instrument, without adding value to you.
Closing thoughts
Recording the classical guitar is a meticulous exercise. Regardless, if you want to record your next album, a video for youtube, or your performances to share with your friends, it is an utterly satisfying process. It is also a reason to practice harder and become a better guitarist.
Before your press "rec" for the first take, allow some time to find the best position, height, and angle. It can be a matter of having an excellent recording or rendering the whole session useless. Small changes in this context may have dramatic results; they act as a physical equalizer.
There have been quite a few times that I had to re-record a performance because of a poor decision, or having to rely on heavy equalization to make it acceptable when it was (almost) impossible (or expensive) to record again at the same location.
I hope that this guide will be helpful in your recording adventures in the quest of capturing the best qualities of your instrument and room.
A Three-Microphone Setup for Recording Classical Guitar
An M/S Stereo alternative.
Classical Guitar is a complex and rich sounding instrument; as such, it sounds better when is recorded with at least two microphones. A statement that you must have read several times already if you hang out at this site. Some engineers argue though that guitar is a relatively small instrument which tends to sound too "wide" when recorded with the most conventional stereo techniques; thus sounding unrealistic in playback.
Neumann TLM 193 and TLM 170 in M/S Stereo Configuration
Mid/Side stereo, which I discuss in my Three M/S Stereo Setups for the Classical Guitar article, is usually praised for its truthful representation of the classical guitar. The elimination of phasing problems and the flexibility it offers during mixing are additional important advantages, however, it is not immune to potential issues. Namely, the collapse of the room information in mono reproduction, and the inability to hear the resulted-combined sound without some processing to the channels (or the use of an M/S matrix). Lastly, symmetrical Figure-8 microphones, required for the "Side" channels, with a balanced response are generally expensive.
Alternatively, the combination of a "Mono" microphone placed at close-proximity and a "Stereo Pair" at some distance, shares some similar advantages without the drawbacks of M/S Stereo. Hence the Three-Microphone Setup is an appropriate option for capturing the subtleties of the classical guitar.
Purpose in position
Austrian Audio OC18 - A Large Diaphragm Cardioid Condenser
The "Mono" microphone is positioned close to the instrument (at about 50cm, although some could go as close as 30cm) to capture a full-bodied sound. I recommend a large-diaphragm condenser with a smooth treble response for this position; as not only it will capture the fullest sound, but the slower transient response of the large capsule will also give a less analytic, more relaxed response.
The "Stereo Pair" is placed a little further away to capture the sound of the room. A pair of small-diaphragm condensers is ideal here due to the better off-axis response and can be either Omni or Cardioid patterns depending on the acoustics. The actual distance depends mainly on the room; accordingly, as the distance increases, the height of the microphones should be increased as well. The distant pair brings to the mix crucial depth, space and some high-end articulation.
Decisions; Player vs Audience
Another way to see the three-microphone setup is as a fine compromise between the intimacy of what the player hears and the somewhat distant experience of an audience member.
During mixing, the three channels can be balanced to the desired sound; from close to distant and everything in between. Either the "mono" or the "stereo pair" can be used as the base sound. Think about a mono capture with some extra space or a distant pair with added fulness.
Examples
For the first recording, I used a Neumann TLM 193 relatively close to the guitar, and a wide pair of DPA 4011As as room microphones.
In isolation, neither the Mono signal nor the AB pair sounds particularly great. The first is somewhat plain and too direct, while body and weight are missing from the AB pair. When mixing all three microphones, the combined sound gets defined and three-dimensional; thus more real.
I made another example of the same setup and the exact same distances, this time with an Austrian Audio OC818 in Cardioid for the Mono duties. The AB pair is still the DPA 4011A. If you have read my Austrian Audio OC818 review, you already know that I love their sound, and I wanted to hear how well they can mix with the DPA microphones.
Combining M/S and Room Microphones
A few months ago, I also experimented with combining an M/S pair of Neumann TLM 193 and AEA N8 up close and a stereo pair of Austrian Audio OC818s at some distance, you can hear the result in this recording of Bach's Cello Prelude no.2.
Some things to take care of
If you want to try the Three-microphone setup, it is important to listen to the recording as a whole before committing to any microphone position. The Mono microphone may be judged alone if you plan to use for the main sound, but don't make bold decisions without listening to the combined audio.
Potential phasing nightmares is one of the biggest drawbacks of this setup, so take extra care to eliminate any issue and check with a proper phase meter plugin regularly (read my article on the Three Most Essential Plugins for Classical Guitar).
Lastly, although the recording should be evaluated as a whole, the close and distant setups might need to be EQed separately. Nevertheless, you may apply a catholic EQ with basic filters and sculpturing.
Cheaper Alternatives
Line Audio CM3 - A budget SDC with an surprisingly good sound
Apart from the aforementioned combinations, any microphone could do a decent job. If you just starting and your budget is limited, buy the best large-diaphragm condenser you can afford and a pair of cheaper small-diaphragm condensers, like the Line Audio CM3/CM4 (read my comparison of the Line Audio CM3 and DPA 4011A).
Final thoughts
I've seen mostly AB, XY, ORTF and sometimes M/S setups explored by engineers and home recordists for the classical guitar. All of which can produce excellent recordings given the right circumstances. Yet, I find that with more elaborate techniques I can capture the instrument, at home or on location, with exceptional precision, without any disadvantages. Except maybe for needing more input channels, cables, stands, and more time for the setup.
A Three-Microphone setup can shine in a very wet hall, as it allows us to capture the body and definition of the instrument while including as much ambience as desired. In a home recording of the classical guitar, it offers great flexibility, if not to provide ambience, it combines the intimacy and fullness of a close pick-up with some extra depth provided by the spaced pair.
So, what do you think? Have you tried a three-microphone setup? Which microphones have you used?
6 Common Mistakes When Recording the Classical Guitar at Home
Part I - The room and the microphones
You just bought a couple of microphones and want to start recording your classical guitar at home; share your recordings with your friends, archive your performances, or start your career as a professional guitarist or recordist. Additionally, recording yourself will force you to look straight into your flaws, thus improving you as a player.
These past few months, I have received quite a few emails and taught several Skype sessions with the focus on recording classical guitars. There are a few mistakes that seem to be common, mistakes that we all do when we first start recording.
In this article, I discuss some of the flubs of the beginner recordist that have to do mainly with the microphones and the room.
You can also read the 6 Common Mistakes When Recording Classical Guitar at Home, Part II article, where I discuss about utilizing a proper signal chain and achieving satisfactory results in post-processing.
Mistake no.1 - Not spending enough time to study the room
Julian Bream - A Life on the Road (Book, 1982)
Every room is different, and If I had to take something out of the brilliant Julian Bream’s book "A Life on the Road" is how essential is to take the extra time to find the spot of where the guitar sounds the best in the room you are; the position in the room and the angle towards the sides are some of the things to consider.
Of course, Julian Bream mainly talks about performances, but the same logic applies to the recording aspect as well. The best sounding spot in the room will allow you to play more comfortably, thus you might sculpture a nicer sound of your guitar; and depending on the microphone technique you use, added ambience or the elimination of unwanted reflections will have an enormous impact on the final recording.
Usually, most of us sit where it is convenient and don't think much about positioning the microphones, as long as they are not in the way. Some others, they like symmetry and will position themselves or the microphones in the middle of a square or rectangular room; the worst sounding spot in a room like this, introducing a plethora of problems that are impossible to remove.
So, try a few different positions, angle the guitar towards one of the sidewalls, maybe sit a little closer to the back wall, to give some space and allow the guitar to project properly. Better yet, ask someone else to play the guitar, ask them to try a few different positions and observe how it affects the sound. Use your ears as if they were the microphones.
Mistake no.2 - Placing the microphones too far away from the guitar
Norbert' Kraft’s distant miking with a spaced pair of Neumann microphones
If you have ever watched any Naxos videos, you must have noticed Norbert Kraft's distant and wide miking. Similar techniques can be seen any many famous recordings. Getting influenced by professional recordists can be inspiring, but also equally misleading as the source material is very different. Techniques that can be excellent in a church, large halls, or even a well-treated studio never apply to the smaller room reality of the home recordist.
By following such techniques you might end up placing the microphone(s) closer to the front wall than the guitar. Even when the microphone(s) are close to equal in distance, it is possible to end up with an overly diffused and roomy sound; as a result, the sound of the small room will be forever embedded in your recording. Getting too wide will also be a problem if the room is not wide enough. Also, the guitar is a small instrument and rarely benefits from a very wide pick up. Therefore, try moving the microphones closer to the guitar but not too close.
Mistake no.3 - Placing the microphones too close to the guitar
Pat Metheny - nylon string recording; don’t try this at home!
After failing with the "church-technique", many of us want to get rid of the small room sound altogether, we have amazing reverb plugins anyway, and start positioning the microphone(s) very close to the guitar, I mean really close. To a similar erroneously path can arrive those with an acoustic guitar background or those who have witnessed some terrible close-miking examples in even famous recordings.
The problem is actually... threefold:
Firstly, by placing the microphones too close, finger and other mechanical noises will creep in, resulting in an annoying and unattractive recording. You may start cutting high frequencies to remove some of those artefacts but sooner or later you'll end up with an immensely dull recording.
Then, most of us usually start with directional microphones, those exhibit a pronounced low-end frequency response due to the proximity effect. One can balance the unwanted boost with careful EQ-ing, but beginner recordists won't have the skills for that. The low-frequency boost combined with the need to cut high-end information will produce an unbalanced imitation of a classical guitar.
Furthermore, the classical guitar is a complex instrument; every part of the top projects different frequencies that they all combine at some point to create a cohesive and rich sound. Normally this point is around the length of the soundboard, about 50cm, that should be the limit of how close you can get with the microphone(s): Greater distance is preferable if the room allows, but, never record classical guitar closer than 50cm.
Remember, classical guitar needs space!
Mistake no.4 - Not experimenting with microphone height, angle and techniques
Placing the microphone(s) at the height of the guitar is a decent place to start, but as microphone height and angle influences so much the overall character of the recording, ignoring other possibilities will frustrate you as you will have to fight with post-processing to get the desired result. It is preferable to spend the extra time and set up the microphone(s) correctly.
Normally, as classical guitarists learn to project their sound slightly upwards, the further away you place the microphone(s), the higher they should be positioned. And, by allowing the microphone(s) to face a bit downwards, so to be on-axis with the guitar, you can achieve a realistic and full-range recording with great definition. This technique will capture what is usually called the "audience perspective".
Spaced AB Pair of Austrian Audio OC818 at 103cm height that point slightly downward
If you notice that the guitar, guitarist or microphones to sound a little sharp, you can angle the microphones slightly off-axis to reach a smoother treble response.
In the case of spaced pairs, it is not uncommon to point the microphones somewhat outwards so that they are not parallel to each other. But in a small room, and at greater distances, additional room reflections will soak into the recording. Thus, I've found that is more desirable to point the microphones slightly inwards or a little higher to achieve a mildly off-axis response but with less "room" in the recording.
For those who pursue an intimate and fuller sound, with a tame high-end and less room, what is called the "player's perspective"; miking the guitar a little closer and with the microphone(s) lower is a good place to start. Avoid placing any microphone opposite of the soundhole, otherwise, the recording will become boomy. For an even fuller sound, place the microphone(s) lower yet, and point them upwards.
The discussion about miking techniques is a complicated one and deserves its own article(s), but until I write it, these ideas should get you a bit more involved.
Mistake no.5 - Not checking for phase problems in stereo recordings
The 2CAudio Vector plugin includes a phase meter and its free!
The classical guitar should be recorded in stereo. Either a pair of spaced condensers or one of the several other stereo setups will do. Except for the coincident microphone techniques, like M/S Stereo and X/Y, any technique that involves two or more spaced microphones, can potentially become a phase nightmare.
Phasing has a noticeable influence on the sound quality of your recording, as due to cancellations and comb filtering it can potentially leave your recorded guitar sound thin and weak. Be sure to check for phasing problems with a proper plugin (I use the 2CAudio Vector, it has a phase meter, plus some other welcome features and its free), adjust the microphones until you minimize phase - everything higher than 80% on the meter is acceptable. You can still compensate for phasing during mixing, but it’s always better to take care of it beforehand.
Mistake no.6 - Thinking that more expensive microphones or preamps will fix all problems
Shopping for new microphones, interfaces and other toys... I mean tools... is fun; a big chunk of writings on this site is about reviewing and comparing recording equipment. But, at this age, pretty decent recordings can be made with a reasonable budget. So blaming the gear is only an excuse for not willing to go the hard way.
Refrigerator racks with outboard equipment can be fun, but we can do a lot with a couple of decent microphones and an audio interface
I'm not arguing that equipment doesn't matter; it does. It just not going to substitute for bad microphone positioning, an unsuitable room or not refined guitar technique. Contrary, more accurate and detailed microphones will accentuate any of the problems that are present.
Learning how to use what you've got, experiment with various microphone techniques and positions; take steps to adjust your room for a better sound. And why not, maybe spend some time practising and try to be well-rehearsed before you press the record button. These are some basic actions to take that can drastically improve your recordings in a meaningful way.
Closing thoughts
Mistakes are part of the learning process; don't be afraid to make them, and don't hesitate to experiment. After all, recording is a journey, and the process of trying things can be a valuable lesson in becoming a more accomplished recordist.
I hope that this article might encourage you to try out different microphone positions, learn and improve your room. Optimistically, the information provided here will guide you to make better recordings.
Austrian Audio OC18 Cardioid and OC818 Multipattern Condenser Microphones Review
Elegant and revolutionary; A modern classic.
Some of my all-time favourite recordings have been made with the AKG C12 (or it stereo counterpart C24), I always adored its distinctly refined sound and musical articulation. Unfortunately, these are quite rare and extremely expensive microphones, so acquiring one is out of the question.
Austrian Audio, formed by ex-AKG employees, promises to carry the much-desired sound of the classic AKG microphones to the 21st century, with outstanding engineering, forward-thinking features and a competitive price. Based around the new handmade ceramic capsule CKR12, and 100% manufactured in Vienna, the large-diaphragm multipattern condenser OC818 and its sibling, the fixed-cardioid OC18, create high expectations.
Brass-ring capsule issues
The new CKR12 ceramic capsule.
The brass-ring CK12 capsule, originally designed for the C12 and early C414 microphones, offers an excellent frequency response with even characteristics on- and off-axis but was so labour intensive and inconsistent that AKG dropped its production and moved on to a simpler design more than 40 years ago. Numerous successors have been presented, and as with all sought-after microphones, a lot of clones have tried to recreate the magic of the famous capsule. But, in the hearts of the audio engineers, the original C12s and C414s, when in good condition, are still the best sounding.
Austrian Audio measured some of the best sounding CK12 capsules available to model the CKR12 which is at the heart of every OC18 and OC818 microphone. The new capsule is ceramic and is made by hand, this design should have a similar response but with greater consistency and durability.
Classy looks
The microphones themselves look rather classy and somewhat understated with a body made of a single piece of zinc-aluminium alloy, finish and craftsmanship are impeccable. The OC818 is silver, while the OC18 is black and lacks the polar pattern selector switch and the second output on the back, but is otherwise identical. The silver finish of the OC818 looks slightly more elegant, but with one drawback; the lettering on the switches is a little to see under certain lighting conditions.
Polar pattern selector, filters and pads on the OC818.
There are 40Hz and 80Hz high-pass filters at 12dB/octave available to control low-end rumble as well as a gentler 6dB/octave at 160Hz to compensate for proximity effect. Carefully chosen high pass filters on microphones and preamps are appreciated here as it is preferable to cut unwanted frequencies before they hit the digital realm. When recording classical guitar, I pretty much have the 40Hz filter engaged at all times.
The sensitivity of 13mV/Pa is respectable, making the choice of preamp less critical. Both the OC18 and OC818 worked flawlessly with the preamps of an RME Babyface Pro FS and my AEA TRP2 external preamps. Both microphones also incorporate -10dB and -20dB pads to protect the internal electronics from very loud sources, which is never a problem with classical guitar, so I haven't tried them. On the other hand, the self-noise of 9dB-A is superb for capturing the subtle plucking sound of nylon strings, especially for very dynamic playing styles.
Dual-output capabilities
A Mini-XLR gives a separate output from the rear capsule of the OC818.
A distinctive feature of the OC818 is the ability to record the two capsules separately and blend them later during mixing with the PolarDesigner plugin to craft the perfect polar pattern. Read my post regarding the PolarDesigner plugin here. Or use the OCR8 Bluetooth dongle and choose between 255 discrete polar patterns in realtime. Unfortunately, I wasn't provided with the OCR8 to test that feature, but the PolarDesigner plugin has been excellent.
Finally, a new plugin developed by Austrian Audio called AmbiCreator makes possible the recording of ambisonic B-format signal with two OC818 microphones. I haven't tried that yet, but I like that the team of Austrian Audio is restless.
Accessories
A pair of OC818s and a single OC18 in the aluminium case.
Austrian Audio was kind enough to send me a pair of OC818s and one OC18 for testing, the microphones arrived in a compact aluminium case which is excellent for storing and transferring them. Wooden cases can sometimes be more luxurious, but an aluminium case is lighter and much more practical. I was also provided with shock-mounts and simple plastic clip mounts. The shock-mounts are compact enough and seem to work well. Saying that, I would like to see them design a more elegant mount as an alternative to match the sophistication of the microphones.
So, how do they sound?
OC818s in AB Stereo.
I first tried the microphones with the Cardioid pattern and my usual wide AB setup. The OC818s captured the articulate character of my spruce/brazilian rosewood classical guitar in abundance. Paired with my AEA TRP2 preamps and RME ADI-2 Pro FS converters, the OC818 pair delivers a gorgeous rich sound with excellent clarity. The tone is bright and defined but in a smooth way, not peaky or harsh neither hyper-realistic.
Austrian Audio OC818 in Cardioid & OC18 - Frequency Response and Polar Pattern
When tested against the Neumann TLM 193, an honest and natural microphone, it becomes apparent that the Neumann is somewhat subdued on the high-mids. And while both microphones can produce a beautiful recording, I prefer the more detailed sound of the OC18 and OC818. I've been using the Neumann TLM 193 for years so their somewhat laid back nature is not new to me, and therefore I usually chose to pair it with a brighter mic, like the TLM 102/103 for instance, to bring back some articulation.
I also tried the OC18 against the Neumann TLM 102, a microphone that I always liked for its natural response, I found that in comparison the Austrian Audio offers a richer midrange with more fluent top-end and defined low-end, thus making the Neumann sound a little hollow in the mids. Arguably, the OC18 is the better microphone, and not much more expensive.
Another microphone I had available for testing is the Gefell UMT70s, a multipattern large-diaphragm condenser built around the famous Georg Neumann M7 capsule and with the finest engineering. It appears to me though that the Cardioid and Figure-8 patterns of the UMT70s were voiced for close miking, and found them to be less desirable for solo classical guitar which benefits from more distant miking. I would imagine that up-close, the Gefell would produce juicy recordings for popular musical styles.
Austrian Audio OC818 in Omni - Frequency Response and Polar Pattern
Both the Gefell and Austrian Audio microphones sounded outstanding in Omni, albeit with a different character. The OC818 produce a more natural, true-to-life recording of the guitar in the room with even response across all frequencies and a fuller low-end, the frequency response graph shows a slightly more pronounced high-end with more gentle high-mids. The Gefell UMT70s in Omni imposes a smooth and creamy sound; juicy and delicious, but not nearly as accurate. Honestly, if I only needed an Omni microphone, I would be happy with either. The OC818 costs less though and sounds consistently excellent in all patterns.
A universal studio microphone
Austrian Audio OC818 in Hypercardioid - Frequency Response and Polar Pattern
I then switched to the Hypercardioid pattern and a slightly more distant set-up. The tighter pattern leaves most of the room out of the recording and the extra distance lets the guitar breath more freely. There is a little less body to the guitar sound but mids and highs are captured in detail and elegance; for challenging rooms, one or two OC818s in Hypercardioid would be the best choice.
For placing the classical guitar inside a denser mix, the tight pattern, and the absence of room ambience of the Hypercardioid pattern offer a vital asset. My instinct when laying down the guitar part for an Elusive Aura recording last July was to use the Omni pattern of the OC818. I couldn’t get the mix right though; the room sound pushed the classical guitar in the background, and in the low strings were fighting with the two cellos. I decided to re-record my part with the Hypercardioid pattern and voila! The classical guitar part almost mixed itself.
Finally, I tried a pair of OC818s in an M/S setup with a Cardioid Mid microphone, read my Three M/S Setups for Classical Guitar post. The truly symmetrical Figure-eight pattern and the full low-end extension should make the Austrian Audio microphones excellent in that application. After processing the Side microphone and balancing the levels, the result is a very realistic image of the guitar with a solid centre image and a polished sheen. My room, even though it's not large, it has a pleasant sound for acoustic instruments due to non-parallel walls, high ceiling, wooden floor and moderate treatment. I can imagine that the OC818s in M/S would sound impressive in a large hall or church.
Austrian Audio OC818 in Figure-eight - Frequency Response and Polar Pattern
Ambience duties
In this Bach's Cello Prelude recording, I used a distant pair of OC818s in Cardioid to pick up the room together with the Neumann TLM 193 and AEA N8 in M/S Stereo placed in the direct field. I think that the Austrian Audio captured the ambience admirably and provided the recording with detail and clarity. In that scenario, the laid back character of the Neumann and AEA combo complements perfectly the brilliance of the Austrian Audio pair.
OC18 vs OC818
I believe it is a smart move for Austrian Audio to release the fixed-cardioid OC18, as many don't need the extra patterns and can save a few hundred euros. According to Austrian Audio, the tolerances of the CKR12 capsules are so tight that any OC18 and OC818 will perfectly match and can be even used as a stereo pair. But, given how much more versatile the OC818 is, costing only (at least for the time) a few hundred more, it is difficult to recommend the fixed-cardioid version.
Conclusions
Austrian Audio OC818.
Austrian Audio are the rightful heirs to the CK12 design tradition, it doesn't surprise me in the least that they developed a new microphone that sounds so alluring. Contrary to a lot of large-diaphragm condensers that either produce a fake sense of clarity with over-pronounced high-end or a smeared response, the Austrian Audio microphones capture ample detail; yet they manage to remain smooth, never harsh or sharp.
With low self-noise, exciting yet clear sound and dual output, the OC818 has become my favourite large-diaphragm condenser for recording the classical guitar. I used the pair of OC818s in Omni for the recordings of my latest classical guitar suites "A Quiet Place" pt. I and II, and with a custom polar pattern on “Baltik Winter”.
Coda A - Apples vs Oranges
I compared the OC818 with DPA's 4006A and 4011A small-diaphragm condensers. The DPA could be my favourite sounding microphones for classical guitar; their truthfulness is unsurpassable but they suffer from a relatively high self-noise, especially the 4011A. The omni 4006A has an impressive 40 mV/Pa sensitivity and is less noisy.
This may seem like comparing apples and oranges due to the different design, but the DPA microphones are the epitome of clarity, definition and precision and I wanted to see how the Austrian Audio microphones compare. Both DPA capsules offer an almost brutally honest pick-up, with breathtaking realism; like “being there in the room”. To my surprise, the OC818 set in Omni and Cardioid respectively comes quite close; maybe not as realistic and precise, but a touch more musical and seductive in exchange.
The OC818 is a large-diaphragm condenser and might not be best suited as the main pair for orchestral recordings. On the other hand, for small ensembles and solo instruments, the noiseless operation and extra musicality can be favourable.
Coda B - Perfect for the Cello
My friend and great cellist Natasha Jaffe came over to my studio one day and we tried one OC818 in front of her Cello. We immediately loved the expressive and balanced sound the microphone captured, the Neumann TLM 193 seemed a little dull in comparison. We tried a couple of different positions to make sure that no microphone had an advantage, the results were consistent across all tests. Natasha decided to buy an OC818 for her own productions, as she felt that the sound of the Austrian Audio was "finished" and “ready”.
Coda C - Recording Debussy
Here another is a real-world example of the use of AB Stereo on Classical Guitar in a professional setting. I used a pair of Austrian Audio OC818 microphones set in a Custom Polar Pattern that combines the best of Cardioid and Omni qualities. The spacing of the microphones is 26cm. The goal was to capture the pure tone of my Angela Walter guitar together with the incredible sounding main hall of the Musikbrauerei in Berlin.
AEA N8 and KU5A Ribbon Microphones on a Classical Guitar
AEA N8 Nuvo Closeup
Ribbon microphones have a very long history, invented in the early 1920s by Telefunken in Germany, and have been used in countless historical recordings of all genres. An ultra-thin ridged aluminium (usually but not only) ribbon is placed between the poles of a magnet that translates vibrations (sound) to voltage.
Recordings made with Ribbon microphones sound very natural, have a full low-end, smooth mids and attenuated highs. They are never over-analytic if anything, they offer a relaxed presentation, making them excellent for instruments which mechanical sounds, like fretting or bowing, can be distracting. Furthermore, their pure characteristics and the bi-polar pattern generate a feeling of "being there" in the room with the musicians.
Ribbon microphones can be quite fragile and require a lot of attention even on how you store them; additionally, being passive they need a lot of very clean gain from the preamps otherwise the can appear noisy, especially with soft instruments and dynamic styles. The advances in HiFi recordings and playback systems, and their inherent downsides pushed Ribbon microphones out of fashion for several decades.
The last decades the trend seems to have shifted, at least partially. Musicians and engineers lust for the added warmth that Ribbon microphones exhibit naturally, and digital environments sometimes lack. For more than 20 years, AEA has dedicated its resources in developing and manufacturing high-quality Ribbon microphones that enable the listener to experience recordings as if he is in the same room with the musicians, and with the recent products, they hope to eliminate some of the inherent issues of this technology.
Nuvo N8 - Active Ribbon with an Extended Top-end
AEA Nuvo N8
Derived from the very well received and fantastic R88, the N8 is a mono version of the former with an added active circuit, meaning that it requires +48 phantom power to function and in exchange, it provides a higher output, making it less dependent on the preamp, and subsequently delivering cleaner recordings. The AEA TRP2 stereo preamp that I use, is specially designed for the AEA Ribbon microphones, and with its extremely clean hi-gain performance and high-impedance, it should deliver stunning recordings.
AEA designed the N8 to be used as in far-field applications, thus making it a better match for acoustic and classical recordings. And in contrast to vintage ribbon microphones, which can sometimes sound dark and murky, the N8, and the R88, capture plenty of high-end and present a controlled low-end.
Unfortunately, KMR Audio (AEA's European distributor) couldn't provide me with a pair to test some of the stereo arrays, like Blumlein or M/S Blumlein that Figure-8 Microphones excel, but I'm excited nevertheless.
KU5A - A Super-Cardioid Ribbon
AEA KU5A
The KU5A is a rather unique design in the world of Ribbon microphones, as not many non-bipolar Ribbons exist, and even less Super-Cardioid. The bi-directionality of most Ribbon microphones can sometimes be more of a burden than a blessing when used in smaller-unattractive sounding rooms. The KUA5 is a front address Super-Cardioid, that eliminates the room and presents the ribbon smoothness and warmth in all its glory, with the benefit of a detailed, extended top.
A high-pass filter of 6dB per Octave at 283Hz makes the AEA Super-Cardioid suitable for close-miking any instrument and the transformer-based, active electronics allow it to function perfectly with any decent preamplifier.
The attributes of the KUA5 make it a perfect choice for concert applications, both for amplifying the classical guitar along with recording purposes. Notably, if you play in an ensemble, The Super-Cardioid pattern will minimise the bleed from other instruments into your amplified sound. Ribbon microphones are also more forgiving than condensers, which can be a huge advantage in live recordings.
Lastly, A common issue with live acoustic recordings is that the Audience can sometimes be as loud as the instruments, the KUA5 will make sure that less of these distractions will find their way to your recordings.
Other Things
AEA KU5A Flight Case
AEA attaches the cables to the microphone on some of their products, and the KU5A is one of them, I'm not sure what to feel about this "feature" as it is nice to have, but makes the transportation awkward. The microphone itself is very well made, the built-it yoke is very sturdy and makes positioning very easy, and the is shipped in a very durable flight case. For concerts or location work, the flight case is undesirably big for the sole reason that it has to have space for the long cable.
N8 Case with Mount and Sock
The N8 is shipped with a durable plastic case which is very convenient for location recordings and for storing the microphone, a shock-like fabric cover to protect the microphone from dust, and a rubber mount that takes the place of a more regular spider mount and takes care of the low-end rumble and vibrations. The small size and weight of the N8 is also worth noting, as well as the standard XLR output, granting easy transportation and effortless positioning.
Conclusions
With active electronics for fewer noise-related headaches and an extended top-end, AEA carries the natural and calm presentation of vintage ribbon microphones to the demands of a modern workflow. Both the N8 and KU5A are excellent ribbon microphones that share the same DNA and are designed for particular situations.
If you want to remove the "room" from your recordings, the KU5A will do just that. While the N8, or better yer a pair of N8s in Blumlein, will put the listener directly into the hall that the performance takes place. Either way, a gorgeous sounding recording is guaranteed.