# Professional Audio Mixing Room / Mac / Stereo Active Speakers



## mikevarela (Apr 6, 2010)

Hi,

I'm excited about getting started using REW. I've calibrated my mix room using an spl meter before, but want to go a little further and make sure the speakers are EQ'd for my mix position.

Question....

I run Pro Tools (hence pro soundcard). To effectively use REW am I to understand that I need to connect the behringer 8000 mic to my soundcard preamp, run REW and between the soundcard outs and speakers.. insert the BFD?

I'm a little concerned because I've been reading up on the process. some places in the docs it says to stay away from preamp xlr connections, and yet on this forum in the connections section, it says this is the best method.


when using the BFD, I'm pretty sure I'm not going to join the two inputs right? dual mono instead of stereo, so I can eq per speaker?

If I decide instead to get two 31 band eq's, should I watch the realtime analysis and adjust the eq's to flatten out the response?

And lastly, should I point behringer 8000 mic at the speaker, or up - and should I read one speaker at a time????

Thanks for the answers, i appreciate the help.


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

Welcome to the Forum, Mike!




> I run Pro Tools (hence pro soundcard). To effectively use REW am I to understand that I need to connect the behringer 8000 mic to my soundcard preamp, run REW and between the soundcard outs and speakers..


Correct. :T




> I'm a little concerned because I've been reading up on the process. some places in the docs it says to stay away from preamp xlr connections, and yet on this forum in the connections section, it says this is the best method.


The “stay away from the mic pre amp connections” is only for the initial calibrating the sound card procedure. After that has been completed, naturally the mic has to be plugged into the pre amp.




> when using the BFD, I'm pretty sure I'm not going to join the two inputs right? dual mono instead of stereo, so I can eq per speaker?


For the BFD, dual mono is the same as stereo – utilizing the inputs and outputs of both channels. However, trust me, you don’t want to use the BFD, it’s very noisy - a low quality product. For home theater uses, people generally only use it for a subwoofer. It’s fine for that, but not for your main-channel speakers.




> If I decide instead to get two 31 band eq's, should I watch the realtime analysis and adjust the eq's to flatten out the response?


Correct. :T Equalize one speaker at a time. They may “require” different settings, according to the RTA, but different settings can play havoc with your stereo imaging. Keep them identical down to about 2-300 Hz. Below that point, if you need different settings to compensate for differences in bass response the two speakers may exhibit, that’s fine – as long as it actually makes an improvement in sound quality.

Here are a couple of other posts with equalizing tips.
http://www.hometheatershack.com/forums/rew-forum/6691-my-first-rew-please-chime.html#post54583
http://www.hometheatershack.com/for...ices/24653-filter-rules-thumb.html#post225699




> And lastly, should I point behringer 8000 mic at the speaker, or up...


If you’re using a mic that’s been custom calibrated, you will have calibration files for I believe three options – 90 (vertical), 45 and 0 (horizontal) degrees orientation. If you’re using our generic file, it’s a 0-degrees calibration. For a home theater measurement there may be some benefit to vertical orientation, which will tend to give some preference to reflected signals over direct in the high frequency range. But for a near-field application like you’re interested in, horizontal will be best, pointed at the speaker you’re measuring.

Regards,
Wayne


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## mikevarela (Apr 6, 2010)

Wayne, thanks so much.

I was a little weary about the behringer anyhow. In a case like mine, where I have rack space in my studio, do you have any suggestions for eq's to buy. I'm trying to keep the cost down a little as I'll soon be moving to surround mixing and need 6 of them.

Also, in calibrating audio post studio, we use a few conventional db-spl levels, so I was concerned about calibration. I'd like to calibrate (eq) my room first, then set the db-spl to the desired level for the type of mixing I'm gonna be doing. (around 78). my concern is that while I'm initially aligning REW to the stated spl level on my radioshack meter, will going through the paces at a rated spl like 75 hange any of the eq plots for when i get calibrated, then move it all up to 78-80 db spl?

thanks again for your response


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## glaufman (Nov 25, 2007)

Calibrating REW to operate at 75dB is just a general guideline. You can run the scans at just about any level that won't have the meter/mic or soundcard clipping.
Small changes in SPL from scan/eq to regular use won't make much difference. The larger the change in SPL, the larger the difference in the EQ you'd want, and most notably in the bass region, or at least so say the equal loudness contours:







And then there's differences in room response, depending on the setup and treatments, with more/different reflections arriving from more/different places.


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

mikevarela said:


> Wayne, do you have any suggestions for eq's to buy. I'm trying to keep the cost down a little as I'll soon be moving to surround mixing and need 6 of them.


You can find a few parametric models mentioned here - look for the ones noted as suitable for full range (main channels) use. If graphic EQs are your preference, I’d recommend the AudioControl C-131. All of these EQs are discontinued and can be had for very reasonable prices on eBay.

I used the C-131 for over 10 years but recently switched to parametric. The C-131 is a top-flight equalizer, but I found parametric EQ to be subtly but noticeably cleaner. That might have something to do with the fact that the adjustments my speakers needed above 6 kHz was accomplished with only one parametric filter instead of 6 graphic filters.




> Also, in calibrating audio post studio, we use a few conventional db-spl levels, so I was concerned about calibration. I'd like to calibrate (eq) my room first, then set the db-spl to the desired level for the type of mixing I'm gonna be doing. (around 78). my concern is that while I'm initially aligning REW to the stated spl level on my radioshack meter, will going through the paces at a rated spl like 75 hange any of the eq plots for when i get calibrated, then move it all up to 78-80 db spl?


As Greg noted, it’s not going to be a problem calibrating at 75 dB, and afterwards “working” at 78-80. But if you’re worried about it, you could always just calibrate at 78 -80 dB. All it take is a re-alignment of the Target setting, which you can do in the REW program.

Regards,
Wayne


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