Last week’s podcast with Philip Graham revealed some of my misconceptions about condenser microphones being a bad choice for live sound. Most sound engineers and musicians are so used to close miking with dynamic mics like SM57s that they don’t really know how to use condenser mics for live performances. I know that I’m guilty of this, but many situations do not require close miking and actually would sound better without it. Let’s take a look at some of Philip’s ideas from his post, Condensers For Live Use.
Myths About Condenser Microphones For Live Sound
There are two main reasons that most sound engineers prefer dynamic mics for live sound:
- They are less susceptible to feedback.
- They are better at controlling bleed.
As for feedback and bleed, it’s all a matter of what the specific microphone is designed for, and how well it is implemented. Both are entirely controlled by the frequency response and polar pattern (directionality) of the mic, and especially the polar pattern across the frequency response. Most people look at polar patterns at 1K, which is in the middle of the mic’s response; but for feedback control the microphone really has to have the same off-axis rejection all across its response range. However, the polar pattern is never the same at all frequencies (except for a ribbon mic’s figure-8 pattern). Almost always, the high frequencies have worse directional control – and it’s usually the high frequencies that are the most problematic for feedback. Taming the off-axis high frequency response can be done through acoustic adjustments to the capsule and careful design of the headbasket, as well as controlling overly-hot high frequencies in the overall EQ of the mic circuitry. I make all these adjustments in my mics, and they have gain-before-feedback that is directly comparable to common stage dynamics like a Shure 58 or an Audix OM5, even in tough acoustic environments.
So it turns out that frequency response and polar patterns have more to do with controlling bleed and feedback than the dynamic/condenser characteristic. You could just as easily have a dynamic mic with poor pattern control at high frequencies as a condenser mic.
Still, Philip cautions against using large diaphragm condenser microphones meant for the controlled environment of a recording studio.
[U]sing mics not designed for the extreme feedback rejection needed on a live stage can be problematic. Many modern LDCs have a quite hyped high end that can be beneficial in the controlled environment of a studio, but on stage it not only makes feedback control difficult, it doesn’t sound very natural.
[U]sing mics not designed for the extreme feedback rejection needed on a live stage can be problematic. Many modern LDCs have a quite hyped high end that can be beneficial in the controlled environment of a studio, but on stage it not only makes feedback control difficult, it doesn’t sound very natural.So, why use condensers?
The big advantage of condenser mics is their sound. A well-built condenser capsule is inherently capable of a smoother response through the full frequency range than a dynamic. This is simply due to the physics of their construction. The moving part of a dynamic capsule, which is driven by the sound in the air being captured, must have much more mass than the diaphragm of a condenser capsule. It will be much more difficult to make it respond to high frequencies, and it will have severe resonant peaks and valleys at various frequencies. A good dynamic capsule is very carefully designed to add a whole series of these acoustic resonances together, which combine to give a fairly smooth response. But it’s still inherently more irregular and “peaky” than a condenser, and less responsive at very high frequencies. Worse high-frequency response is the same as saying that it reproduces transients less accurately. There are certainly some fantastic-sounding dynamics out there – many of which are designed for the studio and are no more appropriate on stage than a U87. But at any rate a dynamic capsule is a complex mechanism engineered to work in a specific microphone body and cannot very effectively be transplanted and modified, whereas I can control almost every aspect of the sound of my condenser mics.
This brings me to my final observation: when I was in school I learned that because dynamic microphones reproduce transients less accurately, as Philip states, they are more forgiving and therefore helpful for inexperienced vocalists. In the interview, Philip disagrees. So, what is your experience? Comment below.
Actually, I have been making selling using and promoting passive microphone boosters for a while now.
This type of device behave just like a condenser mic and needs phantom power. For certain a booster on a dynamic mic will bring a much better signal to noise ratio if anything. But it sort of make a dynamic be very sensitive. In that it takes it to a new level of liveliness without changing its inerrant rejection and pattern quality therefore it doesn’t feedback like a condenser mic.
There are many mic boosters on the market, cloud lifter, fet heat, some using only expensive transformer with not active part and mine Martiaudio booster barrel.
Try it you wouldn’t believe how good it is.
I think it gives a perfect answer to this topic, an in between passive and active mic quality. I think it should be used more live for sure.
Best
Martial
Thanks Martial. Send me one. I’d love to review it for the podcast.
Who carries the Martiaaudio Boost Barrel in the U.S.? Do you sell direct?
Hi Paul, I think you might have the wrong number.
I am using an M-Audio Nova (cheap condenser mike) with battery powered twin Roland BA 330 PAs in outdoor settings. Sounds better that my RODE M1 dynamic mike – and no problems with feedback. You also don’t need to be quite as close or ‘on’ the mike when singing. I get the phantom power from a battery powered BOSS VE1 vocal pedal (reverb and doubling available) but most just use the onboard automatic EQ. I also use this with the RODE (phantom turned off of course)
Hi Bruce!
Wow, what’s automatic EQ??
Hi Bruce
Seen this old post and hope you don’t mind a question.
Looking at micing outdoors for a single solo acoustic vocal player for playing live to a small audience.It is a relatively quiet environment. Will this work as a single mic?
I have recently been thinking about using a large condenser mic for a gig, but didn’t want to chance the feedback, I don’t have a place to check it out and a club date may not be the best testing grounds filled with patrons.
Good article but I quote “There are certainly some fantastic-sounding dynamics out there – many of which are designed for the studio and are no more appropriate on stage than a U87.”
I have heard some fantastic-sounding dynamics but don’t know of any that are less appropriate for stage use than a U87. What manufacturer and models are you referring to here, because I would really like to know? I am just curious because the Sennheiser MD441, Sennheiser MD421, Shure SM7B, EV RE20, and Beyerdynamic M88 are all what I consider great sounding dynamics but they all have been deployed in both studio and stage work!
I bought long time ago a Blue Sparkle and I used a lot that Mic. Almost 5 years using everyday in a Cruise ship. Than after the capsule are broken for oxidation and mechanical issues, I’ve been out of money, and I bought (by impulse) one MXL V69 Valve. Brilliant, warm and precise. But about 5 months that Mic give me signals of overheating ir someting Else. Suddenly stops working, and come back in 1 ir 2 minutes.
Than I was a little bit upset and bought a Blue Bluebird model. Same Brand of that First Sparkle. Nice design modern sound.
The same. In 3 or 4 months the same problem.
Ok, maybe my “screams” have damaged that both capsules. Buy new capsules, replace and… The same problem, but in the first use after the assembly.
I think I’ve figured out what was that problem and maybe someone can corrects me. But in the input signal circuit is a Mosfet transistor. Using the large cardioid that Mosfet overheat because of the transients and Band sounds and that, in intense work like Rock bands or Big bands, Damage that Mosfet transistor.
By the way, in both microfones I put 2 condeser mylar capsules and now, they are working very well (not with the same sound obviously) but pretty close than the first Blue Sparkle that was exccelent.
This brings me to my final observation: when I was in school I learned that because dynamic microphones reproduce transients less accurately, as Philip states, they are more forgiving and therefore helpful for inexperienced vocalists. In the interview, Philip disagrees.
Condenser microphones are most often found in recording studios. However, many condenser mics are now being used in live sound environments. The condenser microphone is a very simple mechanical system, simply a thin, stretched conductive diaphragm held close to a metal disk called the back plate.
Thank you very much for the brilliant write up.