Mic Frequency Response Correction

[RedJoker]

I love reading everyone's input on different mics and their frequency response adding "shimmering highs", "warmth", "air", etc. I used to work in an acoustic lab (but not music related) so the thing that keeps popping up in my mind is frequency response. Since frequency response curves are very common with microphones, do any of you apply a frequency response correction to your mics? A calibration of sorts? This was required even with our high end instrumentation mics.

It just seems to me that through calibration, you could bring your mic back to a flat response and then apply any "coloring" you want back to the mix.

Keep in mind, I was dealing with pure acoustics and not necessarily sound quality so these thoughts are a bit skewed and could result is some harsh, cold, scientific results.

[Bob Womack]

I work in audio post production for video. Virtually everything that comes in from the field has either response bumps or capsule resonances that have to be located and eliminated in order to make best use of headroom and make the subjects sound most natural.

Bob

[rick-slo]

They have flat frequency response mikes. They are called measurement microphones. They have an omnidirectional polar pattern.
For example the Earthworks M30 frequency response






The problem is that these type of mikes sound "cold" and are not very musical to the ear. There is something to be said for the proximity effect of directional mikes
and the little frequency response humps that may add a little high end. Manufacturers design their mikes to have a certain pattern of frequency response to give them
the "character" they want. Also even with a perfectly flat microphone frequency response there are going to be humps and dips in the recording due to the room's
acoustics. Yes, you could have a flat frequency response microphone recording in an anechoic chamber, but that is not what we are used to hearing in the world.

[RedJoker]

Originally Posted by rick-slo

Yes, you could have a flat frequency response microphone recording in an anechoic chamber, but that is not what we are used to hearing in the world.

I think that's what I was getting at. We used calibrated instrumentation mics in an anechoic chamber and could then model different frequency responses to make it more "real world". I was just thinking that if this was done in the scientific community, I assume it would be done in the recording community too.

Thanks!

[RRuskin]

I don't know if this still happens but transducer companies would make the response of their devices look better on paper than they actually were. How? By manipulating the speed of the graph writing equipment. The faster the paper passed the pen, the smoother and flatter the printed response curve. The only maker known not to play this game was B&K, the maker of the most precise sound measuring devices.

[Doug Young]

Originally Posted by RedJoker

I think that's what I was getting at. We used calibrated instrumentation mics in an anechoic chamber and could then model different frequency responses to make it more "real world". I was just thinking that if this was done in the scientific community, I assume it would be done in the recording community too.

Thanks!

There are mic modelers that use convolution and/or EQ to convert one mic to another virtually, which sounds like what you're talking about. There was a new one I just saw advertise that, instead of you telling it what mic was used, so they can normalize it before converting to your target, provide their own mic you are supposed to use. Either it's claimed to be totally flat, or they just know how to correct for their own mic. Can't recall what the new system was, might have been in this month's SOS. There are also similar things for monitors and room - take measurements using a "flat" mic, and automatically adjust your speakers to minimize non-linearities in your room, or to simulate some other monitor.

[RedJoker]

Originally Posted by RRuskin

The only maker known not to play this game was B&K, the maker of the most precise sound measuring devices.

(As I look down at my Bruel & Kjaer notebook...)

[Ty Ford]

As said earlier, flat responses are usually regarded as not pleasant. The other factor is axial response, what the mic sounds like when sound comes in from the sides and not dead on. It's there that many mics fail to sound good because their patterns have weird anomalies that become part of the sound. Schoeps mics, particularly the cmc641 and their new V4 are amazingly free of these artifacts. Without these artifacts, recordings sound better and mixing is a lot easier.

Here's my take on the V4: http://tyfordaudiovideo.blogspot.com...pect-from.html

Regards,

Ty Ford