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Discussion Starter #1 (Edited)
I'm seeking advice on how to set up REW to output over HDMI and input via a USB Mic (calibrated Emotiva EMM1) on a Mac book pro. I had it working a couple years ago but at the time the only was I could get it to work was to use two third party applications, Audio Line-In and Soundflower. Audio Line-In was used to pass the USB Mic signal along to REW and as far as I can tell this is not longer necessary, now REW seems to be getting the signal form my USB mic on its own no without problem. Soundflower was used to direct the test signal from REW to the each individual speaker over HDMI. This allowed you to test each channel individually with 1 HDMI connection from MBP to processor simply by selecting the proper channel in Soundflower/Midi settings.

I tried to use REW the other day and I couldn't get Soundflower to work. I googled it and it seems that the Soundflower app is dead. My question is do you still need a third party app to direct the REW test signals over HDMI to the right channel (5.1 in this case) or is there a way to set this up in REW itself? If you do need a third party app does anyone have one they would recommend for Mac?

In full disclosure I'm kind of a noob so if I'm making this harder than it needs to be please let me know! I really enjoyed using REW with a USB mic + HDMI, it made for quite a simple set up.

Thanks
 

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I just downloaded the most recent version of REW and it looks like this problem was addressed. As far as I can tell you can now select the channel to output right in the "measure" dialog box in REW. Nice.
 

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I've been using REW for a few years, but never managed to get it working via HDMI until today. It's a much nicer method and I can now even check my surround speaker response.

I have a question though: When sending the test signal to HDMI output #4 (subwoofer) should I reduce the test tone level by 10db to account for the 10dB boost in the AVR? If I don't, the response for my left speaker (plus subwoofer) is approx 10dB lower below the speaker crossover point than the LFE is with the same level test tone.
 

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I've been using REW for a few years, but never managed to get it working via HDMI until today. It's a much nicer method and I can now even check my surround speaker response.

I have a question though: When sending the test signal to HDMI output #4 (subwoofer) should I reduce the test tone level by 10db to account for the 10dB boost in the AVR? If I don't, the response for my left speaker (plus subwoofer) is approx 10dB lower below the speaker crossover point than the LFE is with the same level test tone.
Call me an outlaw, I disable the 10 dB of boost in the AVR (mine allows the option). I have not run into any problems with 5.1 music mixes or concert videos or movies I have watched.
 

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Call me an outlaw, I disable the 10 dB of boost in the AVR (mine allows the option). I have not run into any problems with 5.1 music mixes or concert videos or movies I have watched.
OK; "you're an outlaw". ;)

I don't have that option and if I did I would still have to make it up at the subwoofer amp otherwise all subwoofer content would be 10dB lower relative to the other 9 speakers in my set up.

I think I've answered my own question, because I took some measurement without any room EQ engaged (which keeps things simpler) and there is a 10dB difference between a signal sent to HDMI #4 (discrete LFE input) and a full signal, bass managed signal sent to HDMI #1. Therefore my AVR must be doing the 10dB alignment.

If I want to check where reference level is (since my AVR doesn't function this way and the master volume is just marked 0-99dB) then I guess I should reduce the REW signal level 10dB below full scale (ie from -3dbs to -13dbs), then run sweeps slowly increasing the master volume each time until I hit 115dB at the MLP: That master volume setting is then the reference level. (My subs are capable of 122dB at the MLP from previous testing).
 

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OK; "you're an outlaw". ;)

I don't have that option and if I did I would still have to make it up at the subwoofer amp otherwise all subwoofer content would be 10dB lower relative to the other 9 speakers in my set up.

I think I've answered my own question, because I took some measurement without any room EQ engaged (which keeps things simpler) and there is a 10dB difference between a signal sent to HDMI #4 (discrete LFE input) and a full signal, bass managed signal sent to HDMI #1. Therefore my AVR must be doing the 10dB alignment.

If I want to check where reference level is (since my AVR doesn't function this way and the master volume is just marked 0-99dB) then I guess I should reduce the REW signal level 10dB below full scale (ie from -3dbs to -13dbs), then run sweeps slowly increasing the master volume each time until I hit 115dB at the MLP: That master volume setting is then the reference level. (My subs are capable of 122dB at the MLP from previous testing).
Apologies, I was a bit too brief. I remember now that I was referring to my setup with Dirac Live. For the purpose of taking measurements and checking room EQ, etc, since the test signal from REW is being injected into the HDMI where the LFE level would normally be 10 dB LOW, I like to
  • if possible, eliminate the 10 dB LFE boost in the AVR
  • then all the HDMI channel test sweeps can run at the same level (for simplicity) and the sweeps will all fall at the same level and visually integrate nicely on a REW plot
  • in my case, I add the 10 dB elsewhere in the system (downstream, in a miniDSP processor that follows the AVR), so I end up leaving the 10 dB boost out altogether at the AVR.
One way this could be accomplished in your system would be
  • using a pink noise test signal that only covers subwoofer frequencies, send to the LFE channel (subwoofer)
  • adjust subwoofer level down 10 dB - hopefully both with one level change if multiple subs are in use (AVR trim setting?)
  • run sweeps for checking system frequency response
  • reverse the process for getting sub levels back to the normal operating level.
Your process for determining reference level should work fine for your system, assuming that the sub level has been decreased by 10 dB during that process, and gets set back to normal later. Use REW's PPN and the SPL reading to change sub levels easily and accurately. The REW SPL meter with Pink PN (8092 setting), or use the SPL reading on the RTA panel, gives a very stable reading for accomplishing this.
 

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Thanks for your detailed response, I'm using Dirac live too, with an Arcam AVR. I'll have a go at level matching using the REW pink noise noise and SPL meter methods you mentioned. I have used the pink noise with my RS SPL meter so I could have Dirac ON while sending test tones to properly match the speakers/subs. I suspect your method is more accurate though since it will use the UMIK with it's calibration file. :T
 
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