Frequency response neutralization idea... (56k kids, beware of a 42 kb pic)

[shayne_122]

Alright, so my idea was to use a paragraphic EQ to neutralize (flatten) a mic's frequency response. You know how each mic is shipped with the frequency response graph (below)?

http://www.mediacollege.com/audio/images/mic-frequency-response1.gif

What if you were to take this, convert it to it's equivalent on a paragraphic equalizer, and reverse the values?

Would there actually be a more natural, transparent sounding signal? Because I know Blue makes a dynamic mic that uses a +48V to neutralize it's eq, as opposed to running AC voltage through a condensor capsule, and I always wonderered how it was done.

It's probably been thought of before, but I'm curious.

I suppose dynamics and environment would play a part, but whatever.

[Seafroggys]

it might work, it might sound artificial, it really depends.

Of course, many times, a flat response is not desired. There's a reason SM57s are used for professional snare and amp recording, even though they're one of the 'worst' professional mics.

[isp_of_doom]

bear in mind you could also be boosting some unwanted noise.... (I'm not 100% sure though.)

I wouldn't actually say that frequency response looks too bad... unless you're recording a bassy instrument (like... shock horror... a bass or kick drum).

I suppose my noobish answer (though I think it has a good basis) is that the mic wasn't designed to have a flat freq. repsonse....

[Moseph]

Alright, so my idea was to use a paragraphic EQ to neutralize (flatten) a mic's frequency response. You know how each mic is shipped with the frequency response graph (below)?

http://www.mediacollege.com/audio/images/mic-frequency-response1.gif

What if you were to take this, convert it to it's equivalent on a paragraphic equalizer, and reverse the values?

Would there actually be a more natural, transparent sounding signal? Because I know Blue makes a dynamic mic that uses a +48V to neutralize it's eq, as opposed to running AC voltage through a condensor capsule, and I always wonderered how it was done.

It's probably been thought of before, but I'm curious.

I suppose dynamics and environment would play a part, but whatever.


1) +48V is standard for phantom power. It's not just Blue that uses this. All condenser microphones use phantom power, and subsequently tend to have very neutral frequency responses. While 48V might not be the number, the concept is the same: condensers need phantom, and condensers tend to have more neutral responses (even if they require 9V,12V, whatever).

2) There's a reason a microphone is selected for use. It's natural frequency response acts as an EQ and a smartly selected microphone can enhance the way things sound (remember that a microphone is really just one of the many natural "filters" that exist in the studio). I tend to say that to EQ out the natural response of the microphone is basically a waste of the mic's response and a waste of an EQ you could be using elsewhere.

3) All other points aside, try it and see what you think. I think you'll find it's a lot of work for little reward, but maybe I'm wrong. Let us know the results.

[shayne_122]

1) +48V is standard for phantom power. It's not just Blue that uses this. All condenser microphones use phantom power, and subsequently tend to have very neutral frequency responses. While 48V might not be the number, the concept is the same: condensers need phantom, and condensers tend to have more neutral responses (even if they require 9V,12V, whatever).


Oh I'm quite aware of this, don't you worry. I think what you're interpreting wrongly is that I said that it was a DYNAMIC mic manufactured by Blue that was using phantom power to neutralize the eq, which is where I got the idea.


2) There's a reason a microphone is selected for use. It's natural frequency response acts as an EQ and a smartly selected microphone can enhance the way things sound (remember that a microphone is really just one of the many natural "filters" that exist in the studio). I tend to say that to EQ out the natural response of the microphone is basically a waste of the mic's response and a waste of an EQ you could be using elsewhere.


True enough, but aren't most high-end large diaphragm condensors praised for being flatter and more transparent than their lower priced counterparts? I suppose a tube based condensor wouldn't, but something like the U87 has a near perflectly flat cardioid response, except for the expected bass roll off from about 50hz back, and the 8-11khz boost.


3) All other points aside, try it and see what you think. I think you'll find it's a lot of work for little reward, but maybe I'm wrong. Let us know the results.

Well, once I can get this linux based rig up and working in a few weeks, (compiling a usb-audio driver is annoying..) I'll let you folks know.

[Aus_rock_god]

Alright, so my idea was to use a paragraphic EQ to neutralize (flatten) a mic's frequency response. You know how each mic is shipped with the frequency response graph (below)?

http://www.mediacollege.com/audio/images/mic-frequency-response1.gif

What if you were to take this, convert it to it's equivalent on a paragraphic equalizer, and reverse the values?

Would there actually be a more natural, transparent sounding signal? Because I know Blue makes a dynamic mic that uses a +48V to neutralize it's eq, as opposed to running AC voltage through a condensor capsule, and I always wonderered how it was done.

It's probably been thought of before, but I'm curious.

I suppose dynamics and environment would play a part, but whatever.

Yeah, that's pretty standard, most good engineers do it in the studio.

Keep in mind that most mics (a PG57 for example) don't have a flat responce for a good reason. If you pick the right mic for the right job, you'll get a clear sound, particually when you mic up a drumkit, and only want cirtain mics to hear cirtain things.

But, there's no reason why you shouldn't flatten out a vocal mic or a guitar mic.

[Moseph]

Oh I'm quite aware of this, don't you worry. I think what you're interpreting wrongly is that I said that it was a DYNAMIC mic manufactured by Blue that was using phantom power to neutralize the eq, which is where I got the idea.

Good point. I tend to neglect the "dynamics that require phantom power" because, on the whole, there's not a significant number of such mics. Blue has one, Shure has one, I think Rode does as well, but I really am not positive about how many are out there.

True enough, but aren't most high-end large diaphragm condensors praised for being flatter and more transparent than their lower priced counterparts? I suppose a tube based condensor wouldn't, but something like the U87 has a near perflectly flat cardioid response, except for the expected bass roll off from about 50hz back, and the 8-11khz boost.


Yes and no. It's really more about how well they handle the high end. The high end of the audio spectrum is extraordinarily difficult to make transparent and flat, since those the high energy frequencies and can still have a strong effect on the relatively small physics of a microphone capsule. Once you hit a certain price point, pretty much all condensers are nearly flat at the most audible part of the spectrum (30 Hz - 14 kHz).

Well, once I can get this linux based rig up and working in a few weeks, (compiling a usb-audio driver is annoying..) I'll let you folks know.

What DAW software? I tried to get into Linux awhile back to find good free DAW software, but I lacked the patience and ended up enjoying the boutiful amounts of free plugins available for windows (it didn't hurt that most hardware comes with Cubase or Live attached to it). What's your pick? Ardour? Rosegarden? MuSe? Let us know how it is.