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Looking to devise a repeatable microphone comparison test.

Member for

10 years 8 months
I am looking for ways to set up a repeatable microphone test for all of the microphones that my company offers, which will remove any performance variables.
I was thinking about tracking as transparently as possible (Earthworks or Brauner KHE ) into Earthworks 1022 into Avid HDIO16 and then perhaps miking the output of this performance through a genelec 8050.
This way I would collect a database of the relative differences between microphones accurately.
Any suggestions of repeatable methodologies, a transparent capturing source microphone/pre combo, would be appreciated.
Josh

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Member for

10 years 8 months

Littlefish Fri, 05/04/2012 - 20:40
So I like some of the ideas presented! The first and most important property of this test is that it is EASILY REPEATABLE. It will be done whenever new microphones come in.
Reducing the variables to me would mean using the same EXACT sound source every time on every test, with the same preamp, converter, and gainstaging into the daw, miked from the same distance of the source.
Objectively we would fire white noise in an anechoic chamber and get different on and off access responses. This data is already available for the most part though, and doesn't give my customers the subjective experience of being able to hear the relative differences between microphones, which is the aim.
I was thinking of capturing several different sources with the most transparent microphone, preamp, converters money can buy, and then remiking them using the same genelec 8060 monitor, the same distance from the speaker.
Of course we will be capturing the properties of the speaker and preamp/converter combo twice. However a/b switching between these level matched recordings would highlight the relative differences between how the microphones capture their "source."

The help I am looking for is in seeking a very repeatable way of capturing recordings which highlight the relative difference in microphones, holding as many variables as equal.

Thanks for your help!
Josh

Member for

15 years 11 months

RemyRAD Sun, 05/06/2012 - 00:56
Mike, yeah, Yamaha came out with their version of a MIDI controlled player grand piano in the early 1990s. They called it the Disclaviere, which was a take off from the New England Digital Synclaviere. The New England Digital thing was purely electronic. Where the Yamaha utilized MIDI, firing variable pressure solenoids of some type, in their C-3 & 7 actual grand pianos. It's an awesome instrument. Just like computers of today, it goes way beyond punched paper tape. It utilized a computer disk drive and had MIDI ports as well. In fact some of the nice hotels in and around Washington DC had put some of them in place as opposed to having a real guy playing them. So those things were putting hotel piano guys out of a job before we were at NBC. You can purchase pre-programmed performances I think even ones performed by Van Clyburn?

You know when we were still in radio, the late Mark Biggs and I were very seriously thinking about investing in the New England Digital Synclaviere. We went as far as sitting down with the New England digital folks about it. At the time, they were still $250,000. We passed on it. It was an FM synthesizer coupled with one of the first disk drive-based sample record and playback devices. And that was an awesome beast. But like many innovative companies, they were put out of business by the proliferation of modern day computers and software by the mid-1990s. Sting was one of the first on board and New England digital sponsored a special demonstration with him at one of the legendary New York nightclubs where only folks who had attended the AES could obtain a free " aluminum " ticket to this demonstration. He came out with his current band at the time who all began to play. And as they played, one musician at a time would walk off stage while you still continued to hear their performance. It culminated to being just him onstage with the entire band being played back and not sounding any different from when the band members were all playing live. That post dated what Todd Rundgren did back in the 1970s when he came on stage with an MCI console and multitrack recorder and was booed off stage! LOL. Years later, I bumped into Todd Rundgren in the keyboard room at Chuck Levin's Music Center. He was sitting there checking out a keyboard as I was walking through the place. Nobody knew it was him. I had a nice talk with him and actually discussed that ill-fated concert of his because I thought that was a cool concept. He's an awesome dude and was way ahead of his time. I loved playing his stuff back in the mid-1970s when I was at WKTK, years before I came on board at WKYS. Around that same time, I made my way down to speak to Marty Enghauser, who told me to come back after I got my First Class FCC Ticket. Once I did that, it was Scott Standiford that hired me. When I had first stopped down, I was given a tour of the station and sat and talked to Joe Cipriano for a bit. I was really aghast at those old RCA boards. I thought for an NBC owned station that they would have had more modern equipment? Then I couldn't believe that they had pulled apart a custom API board but I found sitting in pieces in maintenance. It was shortly thereafter that I built up my own custom version utilizing whatever pieces of bread board I could find. It was Joe Hall that gave me all this blah blah about not putting transformers in it which I said we needed. But no! And I designed those soft on/off switches for the disc jockey's mics utilizing those Opto devices for smooth fade up & fade down without those obnoxious clicks. That was an awesome little broadcast board I built. And I used those API 325 cards for the outputs. Joe wanted something better and I found a couple of those Dean Jensen 990 Op-Amp modules lying around the shop so I used those. And we had terrible cross talk on the NEMO inputs because of the " no transformer " directive from him. Oh well, you can't fix stupid. So you could never leave one of those interlocking NEMO input buttons selected until you were ready to go on air with them as a result of that. Boy... those were the days. I think Darius got my custom API board? Maybe he still has it? I haven't talked to him in ages since I spoke to Skip, over at Fox. I thought I was good at cutting commercials until I heard Skip's work. I think he's still at Fox? And when you and I were still working together, you might remember that I had an awesome home production studio utilizing and all germanium transistor Phillips 12 x 4 console and an Studio Technologies, stainless steel EMT plate along with my couple of 1176's & 8 API original 550's supplementing the Phillips along with my 3 custom built Scully's & Neumann U-67's when you could still pick them up used for around $400 each, so I had 2. Still do. I parted with that Phillips 12 x 4 when I got my MCI JH-10-16 and also sold my API 550's to Paul Wolff, who I got to know back in 1978. He had just taken over API from Datatronix and he told me he really needed those. So I helped him out by selling in those for only $250 each. He later gave me the second prototype he had built up of the 3124 which I called serial number " 1/2 " along with his first production run which also included serial number 11 which I still have to this day. The second prototype actually had no serial number. And the Phantom supply was on little perph boards. I actually like these first run units better than their current versions. And it was because of me that he came out with the 2510 Op-Amp because in the first 3124 mixer version is output for the mixer section was with NE 5534's. So I scolded him and that he modified mine to have his new 2510's for the mixer outputs. The 2510's was just a 2520 without the pair of output drive transistors. And then I was a happy camper. In the late 1970s I had an eight pack of Neil Muncey, Saul Walker, MELCOR 1731 microphone preamp's. Those 1731 Op-Amps were the precursor to the API 2520's which were virtually identical. And Paul knew that because he was in touch with Saul Walker and was not only making 2520's, he owned API for 13 years. Remember when he was part owner in " No Evil " studios in DC? Before he ever owned API? They had a crappy "APSI" modified PA console. I remember he was so excited when he told me they had purchased a used custom console from Sunset Sound in LA that had API 312/325 & 550's in it. I had been the studio designer, chief engineer of Hallmark Films & Recordings in Baltimore after my days at FLITE THREE in Baltimore. Which was right after George Massenburg had left when they were still called Recordings Inc.. They had offered me the chief engineer job when I was just 16. But I told them that was much too responsibility for a 16 year old. So I got my mentor Tom Bray the position since after 23 years working for Hopkins he got laid off. Then the following year I got in at 17 as a production engineer and trial by fire music engineer LOL. It seems like only yesterday? Where has the time gone?

Oh to be young again...
Mx. Remy Ann David

Member for

10 years 8 months

Littlefish Mon, 05/07/2012 - 16:04
RemyRAD, post: 388973 wrote: Just as Boswell and I described it. You need to stay with the same microphone preamp. You can also utilize a Yamaha Disclavier player piano to gain a truly repeatable and consistent performance as your sound source. I still have my Yamaha C 3 from which their Disclavier was originally based upon and later the C 7 with the Disclavier player feature. I certainly wouldn't use no speakers no how no way as I feel that would not be valid. You could also perhaps offer some music school students that opportunity however? You merely have to tell them to play the directions to Carnegie Hall. Or set up the microphones in a very tight cluster while utilizing a series of identical preamps into your nonidentical converters. I've always hated recording speakers. They sound just like, well, speakers. So if you're going to be a perfectionist about your equipment you should utilize a natural sound source. Perhaps some birds in a cage? Simply because you really want to know what these things are going to sound like with a real sound source and not an electronic representation of a sound source. Utilizing speakers is fine when you are only running a frequency response test. But that's not what this is you're talking about. So either do it right or you're fired! LOL

How's your singing voice?
Mx. Remy Ann David

So same mic pre is possible. so is converter. Disclavier isn't.
All microphones capturing exact same live performance is not in any way feasible for several reasons.
With these being what you have to work with, how would you best put together a test which captures the RELATIVE differences between microphones.

Member for

15 years 11 months

RemyRAD Mon, 05/07/2012 - 16:32
Why do you think that the Disclavier wouldn't be viable to evaluate how a microphone picks up an actual acoustic instrument is beyond me? It's a repeatable performance playback device of a true acoustic nature. Microphones can be placed in exactly the same positions and the playback re-performed precisely the same way each time. Unlike a single performance with a gaggle of microphones all in slightly different positions. And so it is possible. And it's practical. It's personal and it's acoustic. And if you are evaluating the true capability of a microphone consistently placed in the same position using the same preamp and converter, you can't get any closer. We're not talking about a laboratory test procedure but a real-life test evaluation.

And how can anyone feel this is not on topic? You guys really slay me? Where precisely are you coming from? And how would you go about this yourselves? It doesn't even have to be performed in a studio. It can be performed in an actual performance Hall. Such as at a university, a church Tell me please because I am missing something here.

Consistency is good
Mx. Remy Ann David

Member for

10 years 8 months

Littlefish Mon, 05/07/2012 - 21:31
RemyRAD, post: 389257 wrote: Why do you think that the Disclavier wouldn't be viable to evaluate how a microphone picks up an actual acoustic instrument is beyond me? It's a repeatable performance playback device of a true acoustic nature. Microphones can be placed in exactly the same positions and the playback re-performed precisely the same way each time. Unlike a single performance with a gaggle of microphones all in slightly different positions. And so it is possible. And it's practical. It's personal and it's acoustic. And if you are evaluating the true capability of a microphone consistently placed in the same position using the same preamp and converter, you can't get any closer. We're not talking about a laboratory test procedure but a real-life test evaluation.

And how can anyone feel this is not on topic? You guys really slay me? Where precisely are you coming from? And how would you go about this yourselves? It doesn't even have to be performed in a studio. It can be performed in an actual performance Hall. Such as at a university, a church Tell me please because I am missing something here.

Consistency is good
Mx. Remy Ann David

Why will a $12k Disklavier not work, seriously? For the purposes of my test, give me two very compelling reasons why you might suppose it would not work? Two that come to mind are size and price.
Both not at all practical.
I can come up with a litany of other reasons why one might consider this MORE mechanical, less natural, and less repeatable and accurate of a method then simply re miking.
We are not talking about a hypothetical method here.
I was looking for some help in developing something that might work for me personally, as a service to benefit others.
As interesting as it might be none of the historically rich information you wrote about spoke to the original topic. I appreciate the fact that you would try to be helpful.

Member for

15 years 11 months

RemyRAD Tue, 05/08/2012 - 01:45
Well a $12,000 grand piano is both practical and professional in any studio. And with a computer-controlled acoustic piano, it's a lovely way to evaluate microphones. Now they don't have that... that's your problem. So you got something to save up for. You'll blow that much money on equipment and more for any professional studio. And you'll blow that much of a piano. I wish my Yamaha C-3 had the computer interface. But I bought it back in 1978 and I'm not ready to replace it just yet because I don't need to evaluate microphones. Besides, I think evaluating microphones is beginner BS. You just buy them and you put them in your collection and you keep collecting them. If you don't like one, you sell it. And that's what professionals do. Beginners need to evaluate microphones. So go to your local music school and book some time with the Yamaha with the computer audio interface to evaluate your microphones, sonny.

I think you got too much sun in Miami?
Mx. Remy Ann David

Member for

15 years 4 months

Boswell Tue, 05/08/2012 - 08:10
I know both Remy and I have been a bit frivolous in our suggestions, but what were were trying to emphasise is repeatability. You can't begin to make meaningful measurements of differences between microphones unless everything else is exactly the same. This means not only using the same cables, pre-amps and converters, but also placing each mic under test in exactly the same place in the room and giving it a repeat of exactly the same sound source to listen to. You can't do it by putting two mics side-by-side, as they not in the same place. Believe me, a couple of inches matters, even in a mic test.

The other point is that numerical measurements of microphones describe only one aspect of their differences. What matters more is how they sound, and no-one has devised a laboratory or studio test that reliably correlates with how listeners rate individual mics. That day may come, but it's not here yet.

You would also run into problems if your sound source is a reproduced recording. Although precisely repeatable, a reproduced sound is already coloured in a way that could easily mask differences between microphones. Hearing something like a fairground organ may sound like a reproduction, but its punched card input is only an early example of programmed control of a sound source in the way that MIDI is the programming instruction language for a solenoid-driven piano. The sound itself is absolutely live and does not have the hidden artifacts of a recording and reproduction chain incorporated into it.

Many years ago, when I first got 96KHz/24-bit recording capability, I did some tests under studio conditions using a mechanical hammer to operate the mallet on a crash cymbal. I was amazed how much of the high-frequency (>20KHz) and low-amplitude (

Member for

9 years 4 months

Toothgrinder Tue, 05/08/2012 - 13:51
Most basic thing I can think of is a carousel or belt with mics at fixed positions. You could then move the device (noise with that would have to be mitigated) so that different mics come into position, then hit "Go!" and do the test, move the belt/carousel, hit "Go!" and so on.

I like the idea of a mallet hitting a cymbal, or perhaps you could use a snare?

Processing the information objectively would be the hard part. I'd think you'd need to get ahold of industry-standard number-crunching software if you wanted to be scientific about it. Simply sitting and listening to one hit after another would be too subjective, and fatigue would naturally bias the listener: hit 2 would inevitably sound quieter, not as good as hit 1, and hit 3
Some food for thought!

Sort of a Henry Ford approach, I guess. Sounds like an interesting problem. Let us know how it goes.

Member for

15 years 11 months

RemyRAD Thu, 05/03/2012 - 02:46
Honestly, I think you guys are really off base with that? The only real way to compare microphones is through the same preamp and on the same source. But then there is also the difference in spacing, height, distance from the microphones diaphragms. The best way to compare microphones is by listening. That's why we have ears. Actually it sounds like you have too much time on your hands?

Have you considered blunt force trauma?
Mx. Remy Ann David

Member for

10 years 8 months

Littlefish Wed, 05/16/2012 - 01:27
Boswell, post: 389292 wrote: I know both Remy and I have been a bit frivolous in our suggestions, but what were were trying to emphasise is repeatability. You can't begin to make meaningful measurements of differences between microphones unless everything else is exactly the same. This means not only using the same cables, pre-amps and converters, but also placing each mic under test in exactly the same place in the room and giving it a repeat of exactly the same sound source to listen to. You can't do it by putting two mics side-by-side, as they not in the same place. Believe me, a couple of inches matters, even in a mic test.

The other point is that numerical measurements of microphones describe only one aspect of their differences. What matters more is how they sound, and no-one has devised a laboratory or studio test that reliably correlates with how listeners rate individual mics. That day may come, but it's not here yet.

You would also run into problems if your sound source is a reproduced recording. Although precisely repeatable, a reproduced sound is already coloured in a way that could easily mask differences between microphones. Hearing something like a fairground organ may sound like a reproduction, but its punched card input is only an early example of programmed control of a sound source in the way that MIDI is the programming instruction language for a solenoid-driven piano. The sound itself is absolutely live and does not have the hidden artifacts of a recording and reproduction chain incorporated into it.

Many years ago, when I first got 96KHz/24-bit recording capability, I did some tests under studio conditions using a mechanical hammer to operate the mallet on a crash cymbal. I was amazed how much of the high-frequency (>20KHz) and low-amplitude (

This is helpful.

Member for

10 years 8 months

Littlefish Wed, 05/16/2012 - 01:37
Toothgrinder, post: 389375 wrote: I also can't get around thinking it's quite possible that there might be a "toy bias" in mic preferences anyway. If I go to the store and buy Nikes I'm going to think Nike's are the bee's knees and better than Adidas. Some other guy might do the reverse with Adidas, and now we have contradictory biases based on nothing more than I like what I bought (or at least want to justify the purchase to myself somehow.)

Fact is Nike's are great shoes. Adidas are great shoes.

Same applies to mics, I think. And cars, and tools.

As part of my systems design/installation career I found guys would walk around with DeWalt strapped to their belts like a revolver. Is DeWalt a good screwdriver? Well, sure, but at the same time there is a macho factor in one's decision to buy one. I spec 'em out and buy the one with the torque I need, and the voltage I need on the battery, and I end up with what I end up with, you know?

And then I'm thinking Mikita is a superior screwdriver based simply on the fact that I bought one.

I'm not saying this accounts for all preferential differences in microphones, but certainly it's a factor. And it's justifiable, too, if you know your client is aware of the "wow factor" of a really nice mic. They see Rode or Neumann coming at them and that's impressive. That's a selling point for you.

For a dentist it's more of an educational gap with materials. Patients don't know from composite! Buy a cheap on if it works, and increase production. Pocket the difference, baby.

Business and perception, marketing, psychology all interact on these products. Quality and performance, reliability is a given for a lot of them, like Ford or Chevy. They're both pretty good cars, you know? They're not Lambo's or Aston Martins, though.


This is what I hope to dispell somewhat.

Member for

10 years 8 months

Littlefish Wed, 05/16/2012 - 01:43
I think I will be doing a recording of male, female vocals, our baby grand, acoustic bass, drums and a few others though our KHE VM1a AND Earthworks QTC40 into Earthworks 1022 mic pre, into AVID HDX 16x16. Will then remike genelec 8050
Also will record DI'd guitar and bass, to then reamp and mike.
If this method doesn't feel like it is adequately reproducing meaningful RELATIVE differences between microphones than we will quit.

Member for

15 years 11 months

RemyRAD Tue, 05/08/2012 - 19:25
Boswell, I guess we are alone on this? Of course, great minds think alike and so do the other kinds.

There is such a beautiful blend of harmonics from a piano that would present a much more broad evaluation capability from its program repeatability. I like the idea of that solenoid operated mallet. What you did was sort of equivalent to the early MOOG synthesizer that was not polyphonic. Most people could not remember back that far because they weren't born yet. Everybody takes for granted polyphonic capabilities today. I know I'm getting ear fatigue and so, I don't use monitors that cause me much of that. Some of these newer monitors, no matter how good they are, I have found give me greater ear fatigue. But the marketing hype and the manufacturers will tell you otherwise because they're trying to sell you new product. So only you can determine what's best for you. We sit and monitor for hours on end. And when you need to, you take a break. Then you go back, lather, rinse and repeat. And your hair will look great. All of those hairs in your inner ear. How else do you think that real professional engineers do it? Back in the day, even folks like George Massenburg utilized JBL L 100's which were the prettier looking version of the 4310/4311/4312's and some of us still like those like myself. Sure, I've used plenty of others and like plenty of others like Meyer HD-1's. Some of these newer fangled speakers sound good initially.

Your Henry Ford approach would still not be consistent because you are changing the position of the actual sound source in relationship to the room's acoustic environment. Nodal differences would then negate any consistency. You know some of us aren't really idiots even if I seem to be. Although I'm also quite competent at being a professional idiot when I want to be. It's fun to be idiotic at times. We need a laugh once in a while.

Maybe I should try recording a Model T?
Mx. Remy Ann David
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