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Measurement Mic Shootout (EMM-6, WM-61A, RS 33-2055, Audyssey) - Page 12

post #331 of 370
Thread Starter 
Quote:
Originally Posted by spanish68 View Post

On my research, I've found four different correction values charts for the Radio Shack 33-2055 SPL Meter, which I'm now using. Which one of these four listings is correct or the one I should be using? Sorry if this was discused before on this thread. Thanks.


There's no way to tell without a reference mic. Best bet is to just use C weighted compensation.
post #332 of 370
I do use C weighted compensation with the RS digital meter on my SPL measurements. I'm also using option-1 for the correction values for the low bass measurements but wasn't sure if it was the correct one.
post #333 of 370
Thread Starter 
corrections will override c weighted compensation. I was saying not to use corrections, and just compensation.
post #334 of 370
Ive read through this whole thread now, impressive!

I'd like to know where the serial # on an ECM8000 is printed? I have one, and from what I can tell, it must be inside the housing?

Also, for pure audio/music related measurement, why do we bother about below 20Hz, and above 20k?

/Jonas
post #335 of 370
Thread Starter 
There is music below 20hz, there is also a lot of movie content below 20hz. Serial number on an ecm8000 should be on a sticker and on the paper that came with it.

With an accurate mic, you can see exactly what's going on. As an example, I had a huge boost starting at 15hz after Audyssey calibrated everything. With an accurate mic, I was able to EQ this flat fairly easily. Now I don't have to worry as much about crazy excursion issues with my drivers during big bass movie scenes.

post #336 of 370
Older ECM8000's don't have a serial number, newer ECM8000s (Jan 2009 to present) have a label on the mic base with a serial number. The reason I assign serial numbers to mics is because when I started calibrating ECM8000s, they didn't have the numbers.

Quote:
Originally Posted by jonash72 View Post

Ive read through this whole thread now, impressive!

I'd like to know where the serial # on an ECM8000 is printed? I have one, and from what I can tell, it must be inside the housing?

Also, for pure audio/music related measurement, why do we bother about below 20Hz, and above 20k?

/Jonas
post #337 of 370
Quote:
Originally Posted by Anechoic View Post

Older ECM8000's don't have a serial number, newer ECM8000s (Jan 2009 to present) have a label on the mic base with a serial number. The reason I assign serial numbers to mics is because when I started calibrating ECM8000s, they didn't have the numbers.

That explains why my mic dont have a serial # then.

Thanks for the info

/Jonas
post #338 of 370
Maybe this is to be posted elsewhere, but I have searched and not found anything.

I got my ECM a few years ago (abut 4 or so), and I have not been able to find a place to calibrate it here in Sweden yet.

My question would be (for anechoic perhaps): what is the "typical" cal-file for an ECM8000, say from 20Hz-20kHz? And, how much does the ECM vary between units?

Just trying to get a feel for if I need to send it out, for the purposes I use it for..

Thanks alot!
post #339 of 370
Quote:
Originally Posted by jonash72 View Post

Maybe this is to be posted elsewhere, but I have searched and not found anything.

I got my ECM a few years ago (abut 4 or so), and I have not been able to find a place to calibrate it here in Sweden yet.

My question would be (for anechoic perhaps): what is the "typical" cal-file for an ECM8000, say from 20Hz-20kHz? And, how much does the ECM vary between units?

Just trying to get a feel for if I need to send it out, for the purposes I use it for..

Thanks alot!


Here's an image Herb (anechoic) has posted on his company website showing the FR of 85 ECM8000's:



Here's the article where it's posted: http://www.cross-spectrum.com/weblog/2009/07/


Like you said though depending on what you're going to be using the mic for it may not be necessary. I bought one to use for designing speakers... unfortunately I've found there's a lot more to getting a good loudspeaker measurement than just having a calibrated mic lol.
post #340 of 370
Quote:
Originally Posted by lennon_68 View Post

Here's an image Herb (anechoic) has posted on his company website showing the FR of 85 ECM8000's:

Image deleted

Like you said though depending on what you're going to be using the mic for it may not be necessary. I bought one to use for designing speakers... unfortunately I've found there's a lot more to getting a good loudspeaker measurement than just having a calibrated mic lol.

Thanks alot for this!

I use mine to also measure a home loudspeaker, as well as inside car, and I just want to get an idea what the curve looks like. I will use it mainly to find peaks, and reduce those by EQ, but, the final 25% performance comes from tuning by ears anyway
post #341 of 370
As the graphic lennon_68 pointed out, there really isn't a "typical" correction curve, there is a pretty wide unit-to-unit variation.

In terms of sending it out to some place more local to you, have you looked into these guys?
post #342 of 370
Quote:
Originally Posted by Anechoic View Post

As the graphic lennon_68 pointed out, there really isn't a "typical" correction curve, there is a pretty wide unit-to-unit variation.

In terms of sending it out to some place more local to you, have you looked into these guys?

I noticed they were listed on your page as a source for calibration.

However, sending it out (and back) for calibration to germany is like buying a brand new one, so what I am actually considering is buying a second measurement mic, calibrated, from them, and use the ECM8000 I have as a spare. I could then also easily correlate the two mics, to get a "decent" cal file for the ECM8000 I have...

/Jonas
post #343 of 370
Quote:
Originally Posted by jonash72 View Post

I noticed they were listed on your page as a source for calibration.

However, sending it out (and back) for calibration to germany is like buying a brand new one, so what I am actually considering is buying a second measurement mic, calibrated, from them, and use the ECM8000 I have as a spare. I could then also easily correlate the two mics, to get a "decent" cal file for the ECM8000 I have...

/Jonas

That could work, or at least get you in the ballpark.
post #344 of 370
Quote:
Originally Posted by Anechoic View Post
That could work, or at least get you in the ballpark.
Well, if I use both input channels, have the software plot both mic's responses, then I will get the second mic as good calibrated as the first one by computing the differences between them, adding the calibrated mics cal-data into the mixture.

/Jonas
post #345 of 370
Quote:
Originally Posted by notnyt View Post

No phantom power, just straight to mic in on my htpc.


http://www.avsforum.com/avs-vb/showt...0#post20226160

Interesting, out of sheer boredom I thought I'd try to give my Audyssey Mic a go. Can't seem to get it to work at all with my laptop's mic in. Different response each time??
LL
post #346 of 370
Whereas my CM140 is pretty close to my EMM6 (came with a calibration file down to 20hz) to about 13hz ...

post #347 of 370
Quote:
Originally Posted by pbc View Post

Interesting, out of sheer boredom I thought I'd try to give my Audyssey Mic a go. Can't seem to get it to work at all with my laptop's mic in. Different response each time??

Is something jiggling the cable?
post #348 of 370
Nope.
post #349 of 370
Hmm, because when I've seen variances in measurements with the Audyssey mic (off my MacBook) it always seems to jive with something messing with the cable. Such as a hard drive beginning to read.
post #350 of 370
It might be the type of jack. My wm61a (no preamp) will not work on my laptop, but works great on my desktop.
post #351 of 370
Next time I'll try plugging it into the SB Live card I have.
post #352 of 370
Thread Starter 
Does anyone have one of the new RS mics? I'd like to see some comparisons or even take some measurements from one of these.

RS 33-099

http://www.radioshack.com/product/in...uctId=12680845
post #353 of 370
Quote:
Originally Posted by notnyt View Post

Does anyone have one of the new RS mics? I'd like to see some comparisons or even take some measurements from one of these.

RS 33-099

http://www.radioshack.com/product/in...uctId=12680845



Seems to be some improvements there over the original Digital SPL meter. The mic element is moved away from the case (good move), and the SPL range has increased.
post #354 of 370
Are you going to add the new USB based mic's to this shoot out?
post #355 of 370
Thread Starter 
I'd love to, but I don't currently have the money to drop on buying them. If someone wants to ship me some for testing, I would be more than happy to update the results.
post #356 of 370
Has anyone found calibration files for the model mentioned above?

RS 33-099
post #357 of 370
Thread Starter 
You can send it to CSL to get a calibration made if you need. There will obviously be a fee here. Otherwise if you want to send it to me I can compare it to a calibrated mic and post results.

I have a umik-1 now. Short story - correction required for low frequency measurements. This is the measurements from CSL on the unit I have.

post #358 of 370
I was hoping for a simple download link for a calibration file like we have for some of the older Radio Shack SPL meters. I am surprised that doesn't exist yet given Radio Shack has been exclusively selling this model for quite some time now (months if not years).
post #359 of 370
Thread Starter 
Quote:
Originally Posted by 235 View Post

I was hoping for a simple download link for a calibration file like we have for some of the older Radio Shack SPL meters. I am surprised that doesn't exist yet given Radio Shack has been exclusively selling this model for quite some time now (months if not years).

mics are all different. You're not going to get an accurate file off the internet for your unit. Send it to CSL if you want accurate. If you want an idea of how it performs, compare it to a calibrated mic.
post #360 of 370
Thanks, I realize the generic files available here won't be as accurate as having my mic calibrated. However I am not looking for absolute accuracy, rather feedback for relative changes after tweeking. The hometheatershack site also seems to suggest that the generic calibration files would be good enough to use in a home theater setting:

"...so it is our opinion that it will be fine to use in a home theater in most cases"


It's too bad that page does not list the .cal file for the latest RS model mad.gif
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