Studio mics IR

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funkmuscle
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Studio mics IR

Post by funkmuscle »

Hey I'm just wondering if there's anything like this out there, IR files for expensive studio microphones?

So a setup like this:

Code: Select all

cheap Mic --->interface ---> expensive Mic IR--->track

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CrocoDuck
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Re: Studio mics IR

Post by CrocoDuck »

A similar topic was started some time ago.

I reckon it would be possible to do it for reasonably linear microphones. For vintage, heavily distorting microphones, perhaps not very straightforward, as IR would be just a very crude approximation in that case. I think you could browse online and see if there are IRs around.

Measuring mics properly can be very hard and require special rooms, but there are techniques which give a good result by having a vast degree of independence on the environment. However, you need a microphone to use as a reference. I recently got one of these and measured it against a G.R.A.S. measurement microphone. Its frequency response is dead flat, that would do for a good enough reference microphone, amazing reference microphone given the price.

So, the idea would be to sneak in a recording studio with the reference mic, measure the expensive studio one, and go back home with its IR :P .

Honestly I like to record with stuff that is good for measurements. Being flat it means that it adds no color, so it captures the sound field without altering it. I really feel like this is all that is needed, and modern day technology allows to to it reasonably cheaply nowadays.
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funkmuscle
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Re: Studio mics IR

Post by funkmuscle »

oh yeah, I remember that topic now. Looks like I have a wishful dream. :(

Jack Winter
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Re: Studio mics IR

Post by Jack Winter »

CrocoDuck wrote:A similar topic was started some time ago.

Honestly I like to record with stuff that is good for measurements. Being flat it means that it adds no color, so it captures the sound field without altering it. I really feel like this is all that is needed, and modern day technology allows to to it reasonably cheaply nowadays.
Personally I tend to think that finding a mic that flatters the source is much better than an accurate mic ;)
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Re: Studio mics IR

Post by singforme »

If I was a plugin developer with time on hand I'd try the following approach: design a plugin that does three things: 1. eq 2. transient designer 3. Saturation. I think that these three parameters could be used to make a good mic sound close to a lot of different mics - you could have presets for different input-output mics.

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Re: Studio mics IR

Post by CrocoDuck »

singforme wrote:If I was a plugin developer with time on hand I'd try the following approach: design a plugin that does three things: 1. eq 2. transient designer 3. Saturation. I think that these three parameters could be used to make a good mic sound close to a lot of different mics - you could have presets for different input-output mics.
Sounds like a reasonable idea. The only thing that is hard is how to relate real microphones properties to the various blocks parameters. Another way would be to base all those blocks on physical modeling, so to make easier to match plugin configuration to real microphones.
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funkmuscle
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Re: Studio mics IR

Post by funkmuscle »

CrocoDuck wrote:
singforme wrote:If I was a plugin developer with time on hand I'd try the following approach: design a plugin that does three things: 1. eq 2. transient designer 3. Saturation. I think that these three parameters could be used to make a good mic sound close to a lot of different mics - you could have presets for different input-output mics.
Sounds like a reasonable idea. The only thing that is hard is how to relate real microphones properties to the various blocks parameters. Another way would be to base all those blocks on physical modeling, so to make easier to match plugin configuration to real microphones.
Croco, maybe you and Vladimir can if y'all have the time. I know you guys are quite busy.

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Re: Studio mics IR

Post by sadko4u »

funkmuscle wrote:Croco, maybe you and Vladimir can if y'all have the time. I know you guys are quite busy.
Actually, I don't know if we really need to emulate different microphones.
Please look at this video: https://www.youtube.com/watch?v=04vdECGx-8k
There are ya too many different microphones and all sound different. But... After looking at this video, can you answer the simple question: what was the original sound of the guitar?
If you can't then can you actually say about how many information you have lost while recording guitar with some mic and how many information was distorted while recording. And also because some mics can color the sound, you actually can not say how many information was added to the signal while recording the source.
So I don't think that there is a magic pillow to transform a cheap and non-matching to the assigned problem microphone into a non-cheap and matching to the assigned problem microphone.
It is possible to do some dynamics compensation or frequency compensation but... It's a toy that has nothing common with reality.
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CrocoDuck
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Re: Studio mics IR

Post by CrocoDuck »

Thinking about this some more (you guys know I like to think about this stuff) I think that the IR of a microphone might not be that useful actually.

IR and Frequency Response are conjugate properties: they are related to each other by Fourier transform. So, talking about IR is equivalent to talking about how the system described by the IR filters the sound.

Microphones are indeed filters, however they are "pretty hard to deal with filters". I think that most modern microphones have a reasonably flat frequency response when they capture on axis free field sound only (that is, a plane wave sound emitted by an infinitely far away source that is impinging right in front of the mic membrane, in a open infinite space without reflections whatsoever) [*]. This sort of response would be, if we want, the nominal response of the microphones, what we see reported in frequency response plots like this one [*].

As a result, I think that for the most part what makes microphones different from one another is not really the frequency response. Most modern mics have perhaps similar unexciting flat or flattish response (a part perhaps for some resonances).

Probably what makes the real difference is actually directivity, that is, how the frequency response changes by changing the relative source and mic orientation. This alters dramatically the sound as captured in real environments (in which there are reflections, impinging on the mic from many different directions), from real sources that, moreover, have a directivity of their own too. I don't really see any way to model or measure easily directivity of different microphones. Also, there aren't ways to apply it to recorded sound, as the information on the original position and environment is lost. Undo directivity from a recording is substantially impossible for pretty much the same reasons.

So, recording the "nominal" IR of a mic in certain conditions is possible, as well as it is possible to model it. However, it is still not telling the whole story. And I think it might actually be telling not even the most interesting and relevant part of the story.

If the target mic is also nonlinear to an appreciable extent things get even more complicated: IRs do not work well for nonlinear systems.

As a result I would say: perhaps best to have few reasonably good mics and use them wisely. No need to try to emulate expensive ones: they are not the best solution in every case anyway [*]. No simulation/emulation can undo wrongs done while recording (bad mic placement, for example).

[*] This sort of sound can be reproduced, within a frequency range, only in anechoic chambers, by using speaker arrays.
[*] It sounds awfully complicate to measure mics responses then, but actually there are known methods to make it much simpler without sacrificing accuracy significantly.
[*} It would be nice to see a rigorous double blind listening comparison of many different mics. I suspect that the correlation price VS subjective rating might end up being not too significant. It would be a quite hard experiment to set up, though.
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funkmuscle
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Re: Studio mics IR

Post by funkmuscle »

I was looking at vocals but mics are mics and for guitars, they've done it.
The twonotes Wall of Sound plugin mimics mics and positioning
http://www.two-notes.com/en/wall-of-sound
Also in their pedals and racks.
http://www.two-notes.com/en/torpedo-studio
here is a demo on:
https://www.youtube.com/watch?v=vnxWVN9Tsfw
https://www.youtube.com/watch?v=1hfq5Z8PTfg

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sadko4u
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Re: Studio mics IR

Post by sadko4u »

funkmuscle wrote:I was looking at vocals but mics are mics and for guitars, they've done it.
The twonotes Wall of Sound plugin mimics mics and positioning
http://www.two-notes.com/en/wall-of-sound
Also in their pedals and racks.
Oh man, it's not a mic simulation. It's a simulation of complete studio line: amplifier, cabinet, room and microphone.
The only question is: how accurate is the simulation? If I build the same studio line, will I get the same sound? Nobody knows until makes an experiment.
Yep, these nicey picture in the center looks out like that is in reality but this has nothing common with the reality. It's a good simulator that is juggling with parameters and drawing plausible picture.
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funkmuscle
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Re: Studio mics IR

Post by funkmuscle »

sadko4u wrote:
funkmuscle wrote:I was looking at vocals but mics are mics and for guitars, they've done it.
The twonotes Wall of Sound plugin mimics mics and positioning
http://www.two-notes.com/en/wall-of-sound
Also in their pedals and racks.
Oh man, it's not a mic simulation. It's a simulation of complete studio line: amplifier, cabinet, room and microphone.
The only question is: how accurate is the simulation? If I build the same studio line, will I get the same sound? Nobody knows until makes an experiment.
Yep, these nicey picture in the center looks out like that is in reality but this has nothing common with the reality. It's a good simulator that is juggling with parameters and drawing plausible picture.
Exactly it's a good simulation and isn't that what the original topic is based on? Impulse response as far as I know are still not 100% accurate so they are still a simulation so that's what I was asking for is if there's something that can simulate the mics. The second video the guy that was testing it said it came pretty close to his microphone.
Yes it's a full Studio but they also have the cheaper versions which I've tested personally going through the steps at the music store and just using the microphone simulation and it was pretty close. I don't know if it's parametric's or whatever but the thing is it is possible to do. I don't think a simulation will ever be as good as the real thing but close enough is what I was trying to get at.

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CrocoDuck
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Re: Studio mics IR

Post by CrocoDuck »

I think that the simulation approach really shines for synthesized sound.

For example, in guitar rig you can put a simulated mic in front of a simulated cabinet, with the distance and orientation you want. I think that behind the simulation there are generic lumped models of the transducers and generic directivity factors (probably independent of frequency to make things simple). However, as you say, it does not have to be extremely accurate to sound natural and convincing (maybe with the addition of some wise additional effect chain and mixing).

The same happens with pianoteq, for example. This works very well because everything is simulated: sound radiation and sound capture.

I think, though, that your intended application would not unleash the power of simulation to the fullest, as it is significantly different from that:
funkmuscle wrote:Hey I'm just wondering if there's anything like this out there, IR files for expensive studio microphones?

So a setup like this:

Code: Select all

cheap Mic --->interface ---> expensive Mic IR--->track
The complete chain looks like this:

[sound source ---> cheap mic] ---> Interface ---> Expensive Mic Simulation ---> Track.

where [] denote the room where the sound is propagating, which affects it. So, at the beginning of everything, there is already a lot of alteration of your original sound source output. Simulating another environment (or just the mic) after that will not undo it. What you end up with is equivalent to this:

[sound source ---> cheap mic] ---> [ideally flat sound source ---> expensive mic]

It is like you patched your cheap mic output into a sound source in another very neutral room (maybe a mixing room in a recording studio), and recorded with an expensive mic the sound so reproduced in there. Still, the sound keeps on being captured by your cheap mic initially, so there isn't any real improvement. Imagine doing that in real life: sure it would feel odd.

Yes, in theory you might like the sound so produced, however it isn't conceptually different from using just an EQ. I wouldn't be surprised if obtaining something nice to listen to would be easier through a modelling plugin though: it is easier to grasp physical concepts than moving EQ bars around (unless experienced in that). Maybe for many it is easiest to try to get the "oriented sideways" sound by moving a control that sort of does that rather than trying to figure out what EQ setup would achieve a similar result...
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funkmuscle
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Re: Studio mics IR

Post by funkmuscle »

to be honest, I don't even think the best vocal studio mic can save this voice of mine.. :D
I just thought it was possible because of all the devices and plugins out there that seem to mimic

guitar-->amp/amp-sim-->interface-->mic/cab-->track

I figured that something was missing for vocals. Thanx guys for all your input.

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Re: Studio mics IR

Post by CrocoDuck »

funkmuscle wrote: guitar-->amp/amp-sim-->interface-->mic/cab-->track

I figured that something was missing for vocals. Thanx guys for all your input.
Yes, it is reasonable to think about that. We just started scratching the surface of what we can simulate with modern day technology, and simulation quality is growing fast. It is really really interesting, and perhaps many more things will be possible in the near future.

As long as electric guitars are concerned, the problem is orders of magnitude simpler. Electric guitars output voltage signals, which are conveniently mono-dimensional. They lack the complexity of 3D acoustics waves, so what comes after the jack output of a guitar can be modeled very well: we see it mastered by Guitarix. At the end of the process we will have simulated the voltage input for a speaker in a cabinet. We can then simulate the radiated pressure of the speaker and a generic mic response as if it was placed somewhere, in free space. If we want to add a room like linear process a reverb will do nicely.

This means that, as long as you have recorded the voltage output of your guitar without artifacts (any decent soundcard does just that) you can simulate what you want with great accuracy, as there is really nothing to undo from the recorded signal: the simulated system would literally have the same input of the simulator. For recordings from mics, however, this doesn't happen, as the recorded track is already altered by the conditions in which it was taken.
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