# Better Mics than an 8000 ?



## AudioSavant (Dec 27, 2010)

Is anyone getting serious with small condensor measurment microphones here ? has anyone tried an AUDIX TR1, or at least charted the Benhringer plot vs. something like an Earthworks or a B&K ? You must have a reference to achieve to, not a chart plot without reference to compare to. I am afraid that with variances of 3dB to over 6dB, measurments at either end of the octave scale aren't to be trusted. You can [try] to compensate with a calibration chart, but for a microphone that cost's under $60, does anyone really belive the calibration chart, is a polar replication at all stops ? Or in basic terms, is the correction curve for, as an example 250Hz valid at 0 degrees and 90 ? or ???? I think you get my point. Maybe i am being too cynical but
an Aco capsule, or one of the others are used for a reason. A type 1 maybe not mandated, but is the Behringer a true class 2? That is answer is no, and they don't claim to be, so why is everyone here in love with this microphone ? The money ? Any comments on the TR 1 ?:dontknow:


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## SAC (Dec 3, 2009)

LOL!

Watch out! Beyond this point there be dragons!!!! ...and a bit of sarcasm...

I tried to present some of the more comprehensive options that are actually used by professional acousticians and was told not only that such mics and/or pre-amps were not needed, but was warned against pursuing the issue, despite concerns such as yours being very valid - given that one's requirements go beyond simply EQing a sub or wanting to simply get a coarse view of the specular behavior.

From my observation the concern seems to be that while buying gadgets is fine, spending more than $20 something bucks for a Behringer pre-amp and $39 bucks for an RS SPL meter, or, heaven forbid, a calibrated Dayton/Superlux or Behringer mic entering is dangerous territory indeed. In fact, suggestions that one invest in a $69 ART Dual USB pre-amp have many folks becoming apoplectic. So much so that many advise folks to invest in the $300 OmniMic that lacks many important and fundamental tools that are standard in REW simply because they have assembled the 3 interconnect for you as this is perceived as apparently prohibitive - and which also assumes that after the cables are 'figured out' that this same person will experience an epiphany and become a measurement savant.

OK, all jest aside... a better pre-amp and mic can be of great benefit - provided you have the need for them. The primary advantages are significantly increased signal/noise and increased phase and frequency linearity.

But one is wise to evaluate what they anticipate doing in the long run, as simple subwoofer EQ can indeed be done with the most basic tools, while you at least need a 'full range' small capsule omni-mic for the evaluation of specular behavior. And if you anticipate a need to measure noise floors and more critical applications and additional acoustical parameters, you can save a few bucks by investing in the more advanced hardware tools from inception. The consolation being that most of the entry mics and pre-amps are cheap enough that one is not generally facing a significant loss if one outgrows them.

So, the bottomline is to evaluate where you seriously anticipate going with this. If its a casual evaluation of modes, possible EQ and a few ETCs, you will do fine with a basic dual channel pre-amp with phantom power and a basic small capsule calibrated omni-mic such as the Dayton/Superlux or the Behringer. If you fancy yourself seriously going beyond this, you might start saving up for more robust equipment that incorporates internal loopback and greater noise, phase and frequency extension and linearity.


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## AudioSavant (Dec 27, 2010)

Thank you for your candor , appreciated, agreed, and understood. While many, or some cables can be snake oil if you will, just like vinyl barriers for your walls, or rolls of fiberglass, the difference between a proper Class B amp like a BRYSTON in comparrision to a transistor chip on a board of the $500 reciever can be heard by anyone short of being def! Comparing a GENELEC monitor to a B&W, maybe subjective and personal, but comparring either to a HTIB setup is not. The same could be said about precison microphones. Will a $250 A-T sound similar to a Neuman that is 15X the cost for voice work ? yes, but for a singer, with a golden voice, who wants every nuance of sound to be laid down, then they go for the Neumann, or something similar. I am not looking for a GRACE preamp with a Neuman tube microphone, but Iwould like a measurement microphone to be quite accurate, or why bother ? My ears are , as are most people's one of the best tools we have at our hands, if we know what to listen for ! And to answer your comment, measuring, with be beyond tooling around my living room, but in my room, where I do have GENELEC monitors, and B&W, and I listen to SACD, DVD-A, and vinyl, I want to make sure that my RPG Diffusor's are in the right spot, so that I too, can maximize my investment in audio. Thank you for your comments.


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## SAC (Dec 3, 2009)

...Just be careful.

Esoterica for the sake of esoterica, by any rationale, does not make one more skilled at making and interpreting results.

And having the most expensive mic with the most impressive specs does not make one an acoustician.
Put another way, I would rather meet someone who has invested in a knowledge and awareness of acoustics than one who simply has a golden toolbox, as this is the person who is going to understand the power and limitations of the measurements and better relate them to the actual behavior.

Again, one must evaluate what it is exactly that they wish to do, and the ACTUAL requirements of the task.

Do you really need exorbitant S/N to measure subwoofer response? Do you really need exorbitant specs to identify a first order reflection? Are you intending to perform legally admissible certified Noise Level Analysis?

So, while I can indeed appreciate the exotic in lab measurement equipment, there are also worthwhile distinctions to be made in their evaluation - and that is more productive in terms of what specific measurements are required and what exactly one is intending to do, rather than the price of one's system. As it really doesn't matter if the tape measure is precise to 2 decimal places or 27 decimal places or costs $5 or $1M if all you are measuring is the dimensions of a wall surface to the nearest 1/2 inch.


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## AudioSavant (Dec 27, 2010)

Again correct, but I would even opine, that for basic first reflection questions, possible second reflection, and acoustically treating some HT or 2-ch rooms, that aren't filled with the most [critical] or as you say esoteric gear, then you don't really need to measure. Blasphemy ? You have to know what percent of the room needs absorption, diffusion, and reflection, and then you need to know where to place it ! If you use one rig, vs another and they both give you similar results, but you don't know how much material, or were to place it, then all of this is for naught! I have found in MOST high end rooms, there is way too much absorbtion. If I were measuring my own room for product need, I would want my test rig to be the best within reason that i could afford, not for 'esoterica' sake, but if I want a correct RT30, using FFT, I would want a mic capsule to acurately accept the SPL put out in the low-freq. sweep, along with the needed acuracy of measuring the
30dB drop without filtering, dithering, or otherwise not reporting the accurate response. That said, you are not wrong, in that not knowing what the results mean, what to do with them, and what to use to 'correct' them would make all of this an exercise in running tests and reading nice charts. Whoppy.
And regarding the S/N accuracy, or for the layman that may have heard this a million times, but really doesn't know what it means...the SIGNAL to NOISE reading question; Yes, I would want the most accurate S/N I could get in a mic, in a pre-amp (of any type), and in an amplifier, without question. If you are properly testing a room for RT60 or RT30, you want a stone cold, dead quiet room, before you pop a ballon, or otherwise signal the test gear to get a curve. This is S/N in the extreeme. But if you are then testing the phase of the sub, and looking for the best spot, I would think you would also (after correcting phase issue), want the test to be able to reflect the SPL at a select frequency at the biggest variance between the noise floor and the signal. Just my opinion ? Two last comments; For the unitiated, and looking where to place your absorbers for the first reflection point issue...get a friend and a mirror, which is frequency attenuation 101, but be careful, as certain brand names of absorbers, are nothing more than...high frequency vacume's ! Too much use and you have a dead room. Another discussion for another day....then again I get paid for that info.  And lastly, if anyone has a need for a written report, or detailed professional analysis, then I implore you to use an acredited, certified acoustical engineering firm.


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## SAC (Dec 3, 2009)

AudioSavant said:


> Again correct, but I would even opine, that for basic first reflection questions, possible second reflection, and acoustically treating some HT or 2-ch rooms, that aren't filled with the most [critical] or as you say esoteric gear, then you don't really need to measure. Blasphemy ? You have to know what percent of the room needs absorption, diffusion, and reflection, and then you need to know where to place it ! If you use one rig, vs another and they both give you similar results, but you don't know how much material, or were to place it, then all of this is for naught! I have found in MOST high end rooms, there is way too much absorbtion. If I were measuring my own room for product need, I would want my test rig to be the best within reason that i could afford, not for 'esoterica' sake, but if I want a correct RT30, using FFT, I would want a mic capsule to acurately accept the SPL put out in the low-freq. sweep, along with the needed acuracy of measuring the
> 30dB drop without filtering, dithering, or otherwise not reporting the accurate response. That said, you are not wrong, in that not knowing what the results mean, what to do with them, and what to use to 'correct' them would make all of this an exercise in running tests and reading nice charts.




No. Percentage coverage is a generalization meant ti indicate a concept. It is not a treatment strategy.

And treatment (in particular absorption) is applied surgically - specifically at the point of incident sufficient to treat energy of a certain size.
And I can determine this with REW and a Behringer mic or with Easera and a D-Audio preamp and a B&K mic. It makes little difference. 

It matter little how low the mic measures as this is not an issue with specular reflections that only begin with the Schroeder frequency, below which we are dealing with modal behavior.

And RTXX calculations are superfluous is a small acoustical space that lacks a statistically homogeneous reverberant sound field.

With the approach you advocate: "If you use one rig, vs another and they both give you similar results, but you don't know how much material, or were to place it, then all of this is for naught!"

"All of this IS for naught!" As the measurement rig does NOT tell you where to place the treatment nor what type of treatment is optimal!!!!! It provides information that hopefully augments one's understanding such that the designer makes those decisions.

You are fundamentally misunderstanding the purpose of the measurement platform and the nature of the measured responses!





AudioSavant said:


> Whoppy.
> And regarding the S/N accuracy, or for the layman that may have heard this a million times, but really doesn't know what it means...the SIGNAL to NOISE reading question; Yes, I would want the most accurate S/N I could get in a mic, in a pre-amp (of any type), and in an amplifier, without question. If you are properly testing a room for RT60 or RT30, you want a stone cold, dead quiet room, before you pop a ballon, or otherwise signal the test gear to get a curve. This is S/N in the extreeme. But if you are then testing the phase of the sub, and looking for the best spot, I would think you would also (after correcting phase issue), want the test to be able to reflect the SPL at a select frequency at the biggest variance between the noise floor and the signal. Just my opinion ? Two last comments; For the unitiated, and looking where to place your absorbers for the first reflection point issue...get a friend and a mirror, which is frequency attenuation 101, but be careful, as certain brand names of absorbers, are nothing more than...high frequency vacume's ! Too much use and you have a dead room. Another discussion for another day....then again I get paid for that info.  And lastly, if anyone has a need for a written report, or detailed professional analysis, then I implore you to use an acredited, certified acoustical engineering firm.



Sorry, but S/N is important to the degree that it masks other problems.
We don't use Dirac impulses or pop a balloon. Instead we use frequency sweeps that are MUCH less sensitive to ambient noise . 

And if I am using TEF with TDS, we commonly test sound reinforcement rigs _while simultaneously listening to a CD of choice - and if you are doing this during a concert set, the crew is most likely listening to heavy metal at a pretty good level (as it seems to work like caffeine), while chairs are being (noisily) set, tow motors have their backup warning beeping and the environment is anything BUT quiet._ 

FFT, conversely, is less noise tolerant as it is unable to distinguish the test stimuli from the ambient noise, and this is only practically overcome by timed averaged measurements that average out transitory impulsive signals.

But this is a practical consideration. And in a non-commercial small acoustical space this is not normally an issue - except to stop the occasional dog barking or the baby crying.

In short, there are legitimate reasons to use higher tolerance components, and many of us do as our applications run the gamut from casual to critical, including those requiring certification for use as legal evidence.

But the brand and price of your stereo equipment does NOT determine the necessary precision and tolerance of the measurement platform, regardless of how exotic one may feel their setup to be. 

The degree of precision and tolerance is determined by the nature of the specific measurement being done and the nature of the environment. ...Not by the price or label of the equipment used to produce the sweep.


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## jrhager84 (May 26, 2012)

There's been a shootout on realtraps that show that the Behringer and Nady microphones are only a few dB off from the higher end Earthworks/etc. mics. I actually plan on picking the CM100 up (as it's local) to see how it fares. Hope to have helped a bit!


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