# Trying to learn how to do room equalization



## brad l taylor (Mar 8, 2010)

Hi Home Theater folks:

I found this site after searching for software to help me equalize my room. I have an Onkyo amp with audyssey but I actually think things sound better with the processing turned off and manual eq. This has got me interested in really measuring things and I'm looking to set myself up to do some real measurements. (I'm an electronics engineer at work so I'm comfortable with engineering measurements). 

based on some web surfing, I think I'd like to get a good mic and USB input to do this work . I was thinking of getting a Blue Microphones Icicle and a Behringer ECM8000 mic. Anyone have any experience on how this might work out?

I'd appreciate any advice in this area
-
Brad


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## recruit (May 9, 2009)

Hello Brad and welcome to the Home Theatre Shack :T

I'm moving your post to a more appropriate forum where hopefully you will get the answers you are looking for 

Also please check out our  REW Forum  & our 
BFD | Electronic Equalization Devices Forum as there is also plenty of info and lots to learn and ask in these areas too.


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

Hi Brad,

Room measurements will only be as good as the measurement platform and the equipment connected to it. We can provide you with the platform, REW. The problem with the "equipment connected" is that none of it that is affordable is perfectly accurate. To overcome this situation, calibration files can be added to REW, to remove the deviations from flat response that you will find with mics and sound cards. 

Your best bet will be to buy an ECM8000 mic complete with a custom calibration file from our preferred vendor, Cross Spectrum. We do provide a generic calibration file, but there is simply too much deviation from one mic to the next to insure you’ll get perfect accuracy from a generic file. (See mic variations graph here.) 

As for the sound card/mic pre amp, REW can generate a calibration file for it.

The problem with a USB mic pre amp like the Blue Icicle is that REW cannot generate a calibration file for it. In order for REW to generate a calibration file, a full duplex sound card with line-level inputs and outputs is required. Therefore, the only way you can expect accurate results from the Icicle would be if the manufacturer could provide a frequency response plot for it. If you can get one, you can generate your own calibration file that could be loaded into REW.

Regards,
Wayne


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## glaufman (Nov 25, 2007)

+1 on everything Wayne said, and welcome to the Shack!


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## drdoan (Aug 30, 2006)

Welcome Brad. Wayne is spot on. Have fun. Dennis


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## brad l taylor (Mar 8, 2010)

Thanks guys for the warm welcome - Unfortunately I just ordered the ECM8000 last night from amazon and the blue icicle preamp. I guess I should have waited for your good advise, but maybe I can find a way to use it. 

Playing around with my existing mic I can see I have a lot of work to do just learning how to use REW. (I'm using the mic from the onkyo eq). In fact I realize that I totally don't understand how my amp is working since it doesn't seem to be driving my subwoofer the way I expect. Also the onkyo is shutting down when I run the auto eq ;( so I'm not sure what's going on. 

I'll check back in when I have some results


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## glaufman (Nov 25, 2007)

Hi Brad-
Don't fret too much about the results you get using REW with the mic supplied with your Onkyo. All affordable mics are going to require a calibration file to adjust for anomalies in their response. Since I believe you wouldn't have one for the Onkyo mic, you wouldn't be able to load it into REW, reducing the accuracy of the results. Onkyo builds a cal file into their other equipment to adjust for the mic.


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