# ECM8000 + xlr to usb adapter



## upking (Apr 8, 2012)

Hello guys I came here to get some suggestions to buy my "measurement set", I was thinking about buying an EMC8000 and an USB to XLR adapter like this one 
http://cdn.mos.musicradar.com/image...aptop-audio-interfaces/blue-icicle-660-80.jpg or something similar.
That's cause I have a very low budget and I don't have an offboard sound card eventough my onboard card is not so bad, it's has 8 channel support, spdif support and 192khz/24bits output and 96khz/16bits input line or microphone. The codec is ALC1200 which people say it's the same as ALC888.

I don't know what will be better, an adapter to usb or plug the mic in a pre-amp and then to the onboard card.

Anyway, I've got only 50 dollars to play around with that usb adapter or pre-amp, what should I do?

Thanks for help and have a good day!


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## Wayne A. Pflughaupt (Apr 13, 2006)

I don’t know of anyone who’s successfully used one of those, but it’s possible someone did and didn’t mention it. Try doing a search for "icicle." A big problem with them is that you can’t generate a calibration file, so the accuracy of your readings will be anyone’s guess.

Regards,
Wayne


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## SAC (Dec 3, 2009)

Save up another ~$30 ($19 for the pre-amp and a few more bucks for the cables) for an ART Dual USB Pre ($69 from B&HPhoto) and a few interconnects from Monoprice.com.


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## upking (Apr 8, 2012)

Wayne A. Pflughaupt said:


> I don’t know of anyone who’s successfully used one of those, but it’s possible someone did and didn’t mention it. Try doing a search for "icicle." A big problem with them is that you can’t generate a calibration file, so the accuracy of your readings will be anyone’s guess.
> 
> Regards,
> Wayne


What do I need to generate this calibration file? I tought I'd only need the mic response curve.
My onboard soundcard is at least acceptable for measurements? Cause if it is I'll buy a pre-amp.
edit-
I've just measured my soundcard, seems good even tough the cable I used have some plug problems

http://imageshack.us/photo/my-images/708/soundcardmeasurement.jpg/

I'll probably get a better result with better a cable ( this cable really have problems with the plugs)


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## SAC (Dec 3, 2009)

At the risk of further muddying the waters...

The use of various analogue to digital conversion tools may be fine.

The problem here is two-fold.

One is that you are new to this and the basic setup and functionality is an issue, such as the need for, generation and use of basic frequency calibration files for mics and soundcard (and your conversion device!) as well as for timing calibration in the form of a hardware loopback.

Additionally, in addition to questions about the basics, you are attempting to use a non-standard device and configuration and challenging us to provide tested configuration advice for a _non-supported_ configuration!

My suggestion is to first deal with the tried and tested supported configurations.

After you have that down and understand the various factors and variables at play, _then_ experiment with various alternative hardware and topological configurations and you will be free to experiment and more fruitfully determine answers to many of the questions that you have now.


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## upking (Apr 8, 2012)

SAC said:


> At the risk of further muddying the waters...
> 
> The use of various analogue to digital conversion tools may be fine.
> 
> ...


Allright so I'd go with a mic+pre-amp but what about my soundcard, is it acceptable to use? (take a look at the graph)

Measurements:

http://imageshack.us/photo/my-images/708/soundcardmeasurement.jpg/


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## Wayne A. Pflughaupt (Apr 13, 2006)

A swing of ±5 dB is worse than what we’re used to seeing with most sound cards, but it should work. Given your budget you might try the Behringer ZENYX 502 for your pre-amp (naturally its functionality for this application assumes your soundcard has line level inputs). Ultimately the weak link in your measurement chain will be the mic - I presume it does not have a custom calibration but will rely on our generic calibration file?

Regards, 
Wayne


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## upking (Apr 8, 2012)

Wayne A. Pflughaupt said:


> A swing of ±5 dB is worse than what we’re used to seeing with most sound cards, but it should work. Given your budget you might try the Behringer ZENYX 502 for your pre-amp (naturally its functionality for this application assumes your soundcard has line level inputs). Ultimately the weak link in your measurement chain will be the mic - I presume it does not have a custom calibration but will rely on our generic calibration file?
> 
> Regards,
> Wayne


Hmm. Could this swing be because of the cable? Is there anything I could do to improve the response? Wouldn't the Calibration correct the bad response of my soundcard? And yes, my card has line input but I didn't got one thing... You said that the weak link will be the mic, I thought it were a good mic for measurements... and yes I will rely on the generic calibration file or even no calibration... and I'll probably use the Zenyx 502 for pre-amp.
Thanks 4 Helping!


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## Wayne A. Pflughaupt (Apr 13, 2006)

No worries, the calibration file will correct for the sound card’s deviations in response.










Like the soundcard, the mic is only as good as its calibration. The picture below shows the measured deviations in response of a sizable number of ECM8000 samples. Obviously a generic calibration file is no substitute for the custom calibration that Cross Spectrum offers. If all you’re interested in is “FYI” full-range measurements, then the generic calibration file is fine. The custom calibration would only be needed if you intended to employ equalization for the main speakers: Obviously you don’t want to equalize based on less-than-accurate measurements.









​
Regards, 
Wayne


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## upking (Apr 8, 2012)

Wayne A. Pflughaupt said:


> No worries, the calibration file will correct for the sound card’s deviations in response.
> 
> 
> 
> ...


Hm... got it, I don't like to equalize the sound but maybe I'll do it...(with software on my pc) the problem is that I can't have a calibrated microphone cause I'm from brazil and I'll import it, and I don't know any company that does this kind of job around here and If I find one it will probably be really expensive. So, is there a way to calibrate the microphone by my self?


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## SAC (Dec 3, 2009)

I apologize for mentioning this, but there are a few important distinctions that are being glossed over here.

One is the "equalization of the speaker".

Ignoring crossover issues, a speaker's _direct_ signal can be EQ'd, one of the actual areas where EQ can be correctly applied, as the direct signal considered alone is minimum phase (again, ignoring potential non-minimum crossover issues).

But is what you imagine to be a measurement of the speaker's direct signal, actually the speaker's direct signal? Sounds like a trick question, doesn't it?

But the fact is, one cannot simply take a measurement of a speaker** in a room and then proceed to imagine themselves correcting for the direct "speaker" response, as the frequency response measured in situ is properly a speaker-room response whose actual display is a non-minimum phase summation of the superposition of the direct and indirect room influenced signals. And not only does this not provide an accurate summary of the direct speaker signal, but it is a predominantly non-minimum phase that those infernal industry giants who happen to lead the naysayers are absolutely correct in asserting cannot be corrected by equalization.

So measurement and subsequent correction requires just a bit more understanding of what it is that is being measured and exactly how one imagines they will correct the properly isolated and identified issues at hand.

And the frequency response is notorious in that it fails to provide any detail as to the various myriad contributing factors that all interact to cause the derivative frequency response complete with various deviations and comb filtering anomalies - in other words, ALL of the various causal factors that must be identified and addressed in a granular fashion in order to actually and properly correct for the variations incorporated in the frequency response. the fundamental reason one *cannot *simply by brute force EQ the frequency response and 'straighten it out'.



**The means of actually and properly making an effectively anechoic speaker response measurement outside of an anechoic chamber is outside the scope of this post.


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## Wayne A. Pflughaupt (Apr 13, 2006)

The only way I know of to calibrate the mic yourself would be if you had access to another one with perfectly flat response.

I believe Cross Spectrum ships internationally; you might get in touch with Herb and see what he says.

Regards, 
Wayne


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## JohnM (Apr 11, 2006)

upking said:


> Allright so I'd go with a mic+pre-amp but what about my soundcard, is it acceptable to use? (take a look at the graph)
> 
> Measurements:
> 
> http://imageshack.us/photo/my-images/708/soundcardmeasurement.jpg/


That is a very abnormal soundcard measurement, there must be something wrong in the setup to generate that - it might be the result of having some kind of sound effect or EQ preset active.


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## upking (Apr 8, 2012)

JohnM said:


> That is a very abnormal soundcard measurement, there must be something wrong in the setup to generate that - it might be the result of having some kind of sound effect or EQ preset active.




Thanks god I saw this post... I was perfectly sure about no eq preset but I decided to check again, and suddenly discovered that there was really a problem with EQ preset.
Here's the right measurement, much better










Sample rate: 48000 Hz
-3 dB points: 1,8 Hz, 20,097 kHz
Input device: Entrada (Realtek High Definitio
Input: LINE_IN (Volume principal)
Channel: Left
Input volume: 1,000
Input RMS target: -6,0 dB
Actual RMS at 1 kHz: -7,0 dB
Output device: Alto-falantes (Realtek High Definition Audio)
Output: No output selected
Sweep level: -6,0 dB
20 Hz .. 20 kHz flatness: +0,1, -2,8 dB~


I decided to get a Calibrated microphone, but I'm in doubt about ECM800 or EMM-6... The Idea of the Equalization is to compensate some problems that my room might have, there will be no professional use in this, only hobby... Wouldn't that work, to position the mic in the listenin place, measure the response and then EQ taking in consideration the default response?

After all, Do I have to buy a pre-amp plus soundcard like tascam 144 or a usb sound card + pre amp or just a Behringer ZENYX 502 using it with my onboard card?


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## Wayne A. Pflughaupt (Apr 13, 2006)

upking said:


> I decided to get a Calibrated microphone, but I'm in doubt about ECM800 or EMM-6...


From what I see at Herb’s (Anechoic) recent "State of the Microphone" thread, it appears the EMM6 is the way to go.




> The Idea of the Equalization is to compensate some problems that my room might have, there will be no professional use in this, only hobby... Wouldn't that work, to position the mic in the listenin place, measure the response and then EQ taking in consideration the default response?


It’s hard to say definitively if EQ can help, not knowing anything about your room or set-up. Often it can. My “rule of thumb” for main-channel equalization is to generate parametric filters to flatten measured response, then do some listening with a music source you’re familiar with, and switch each filter in and out and decide if it’s making an audible improvement. “Throw out” any filters that don’t offer an audible improvement.




> After all, Do I have to buy a pre-amp plus soundcard like tascam 144 or a usb sound card + pre amp or just a Behringer ZENYX 502 using it with my onboard card?


If your sound card has a line level input, you can use something like the ZENYX 502. If not, you’ll need an “all in one” card like the Tascam or similar.

Regards, 
Wayne


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## upking (Apr 8, 2012)

:sad:


Wayne A. Pflughaupt said:


> From what I see at Herb’s (Anechoic) recent "State of the Microphone" thread, it appears the EMM6 is the way to go.
> 
> 
> It’s hard to say definitively if EQ can help, not knowing anything about your room or set-up. Often it can. My “rule of thumb” for main-channel equalization is to generate parametric filters to flatten measured response, then do some listening with a music source you’re familiar with, and switch each filter in and out and decide if it’s making an audible improvement. “Throw out” any filters that don’t offer an audible improvement.
> ...


Yes, my Soundcard has the line imput, and what about the measurements I've done (my last post), are they good for doing that kind of stuff?

My idea was to measure at first with no equalization, then try to compensate the response step by step like if I 0db is the reference point and in 200 hz the graphic shows that it's with -6db then I go to the EQ, and add +6db to 200hz, for sure that I'll take care to not add to much gain, trying to reduce the gain of the other frequences than adding gain to 200hz (like the example) to prevent clipping. As if the lowest point is 200hz -6db I'll try to make everything go to -6db so that I becomes more linear.

Sure that If I don't like the result I'll just turn off the EQ and that will be all..


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## SAC (Dec 3, 2009)

upking said:


> The Idea of the Equalization is to compensate some problems that my room might have, there will be no professional use in this, only hobby... Wouldn't that work, to position the mic in the listenin place, measure the response and then EQ taking in consideration the default response?


I apologize for appearing to be 'argumentative', but EQ CANNOT compensate for "room " problems dominated by the interaction of out of phase specular signals above ~250 Hz. It use is limited to the slight (3-6 dB, per Toole in Loudspeaker & Rooms: Working Together) reduction of in-phase modal peaks (and equally importantly, NOT of modal nulls).

It is one useful tool among many, but it has some severe limitations that must be recognized lest it cause more problems, as it is anything BUT a universal cure-all.

To compensate for issues stemming from speaker-room interaction requires room treatment.
This has been well established by (I love how they are referred to as "naysayers") folks such as Heyser, Davis, D'Antonio, VMA Puetz, Russ Berger, Dr. Patronis, Peter Mapp, Manfred Schroeder, Don Keele, Bob Todrank, Floyd Toole, and other prominent acousticians of whom I could go on listing all day, who do not simply suggest this, but who adamantly insist upon this based upon physics.

EQ is great to adjust the characteristic frequency output levels of the direct source, but it is NOT the proper tools to address anomalies caused by the combining (properly called "superposition") of non-minimum phase direct and indirect signals in a bounded space.

The fact is, modifying the direct on axis signal frequency response does not provide compensation to alleviate cancellation and additive errors caused by the superposition of similar, but delayed (out of phase), indirect reflections.

For this there are other more appropriate legitimate solutions.

So, if you want to use EQ as one tool (out of several) to help address low frequency modal peaks, great. But equally important is to recognize its limitations as it is NOT the proper tool to address response anomalies caused by modal nulls nor the interaction of speaker and room above ~250 Hz.

Ironically the "naysayers" who have gone to great lengths to assert exactly this are the giants in the acoustics field.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Hey upking,



upking said:


> My idea was to measure at first with no equalization, then try to compensate the response step by step like if I 0db is the reference point and in 200 hz the graphic shows that it's with -6db then I go to the EQ, and add +6db to 200hz, for sure that I'll take care to not add to much gain, *trying to reduce the gain of the other frequences than adding gain to 200hz*


Unfortunately, that approach really doesn’t accomplish anything. Using the EQ for wholesale gain reduction only means the lost gain will have to be made up elsewhere. This post will help explain. It’s best, as much as possible, to simply EQ only where it’s needed and don’t mess with the rest.

Regards, 
Wayne


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