Simplified REW Setup and Use (USB Mic & HDMI Connection) Including Measurement Techniques and How... - Page 5

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Originally Posted by mogorf 

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Originally Posted by kbarnes701 

Feri, can you elaborate for me please?  Where do I set the test signal volume? WIth the discussion in Post 2 about using 100dB for the test signals (I think my house might fall down with 100dB from my two Submersives - LOL) I am cautious about the test tone volume. Any help you can give would be appreciated.

Keith, I really wouldn't like to go ahead of Jason, I'm sure he will include this part in his descriptions when time comes.

Understood.

OK. Thanks.

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3. This will become interesting when we engage MultEQ and especially DEQ, because these twins will need calibrated SPLs vs. test signal levels. Remember the good old equation where -30 dBfs is supposed to render a 75 dB SPL at the MLP. Now if you feed 0 dBfs into the system the SPL at the MLP should be exactly 105 dB for satellites and with the +10 dB boost of the LFE the Submersives should deliver in your room a total of 115 dB SPL (flat). What did you say about rattling in your room? Yikes! With a 115 dB SPL at 10 Hz you will have one final rattle in your room before it falls down. Household insurance policy OK? Make sure REW tests are included in All Risks clause! 

Hahaha - LOL (literally).

I would like to add some comments about the purpose and direction of this thread.  These comments are prompted by Jason's answers to my list of questions.  While the answers are interesting, I am concerned that the information is too much, too soon.  There are many topics ahead of us, and we should discipline ourselves to focus on one important topic before we move on to the next.  Remember when you were taking those college courses?  On the first day of class, you received a syllabus which provided the list of topics to be covered, and the order in which they would be presented.  (I know, it's been over 45 years since I saw a college classroom, but I still remember...)

I think we should agree on an outline for the thread, focus on each item in order, and master it before proceeding.  An example of an outline:

- Assembling the hardware and software components comprising the REW kit, and mastering the techniques of configuring the components so REW is completely functional.

- Calibrating the mic and soundcard in preparation for taking accurate measurements.

- Generating and interpreting frequency response measurements.

- Generating and interpreting waterfall graphs.

- Generating and interpreting ETC graphs.

- Case studies:  Picking forum participants' measurements, identifying issues, and discussing approaches on resolving the issues as a team.

What I am trying to say is that if we try and discuss all these topics at the same time, we are going to get bogged down, and some of us may become discouraged and leave.  REW is an elephant, and we need to be the pygmies, eating it one bite at a time.... 

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Originally Posted by JChin 


Hi Jerry, totally agree with you on this. I was just going to post that I have the same 2 channel output as you until I did more clicking . I now have all 8 channel and that log sweep for #4 output show a few things that need tighting down .

Come on, don't tease me.  What do you mean by "until I did more clicking"?  Please provide the details of how you resolved the issue.

I hate to say it but, for the time being, I am admitting defeat.  I can only output to two channels, front left and right.  And by virtue of bass management, the subs are receiving a signal as well.

This should not be a huge issue.  After all, I made a point to Feri that I wasn't very interested in testing the response to the surrounds and effect speakers anyway.  So, with the REW as currently configured, I will be able to test:

- Left speaker only (by setting it to Large to disable bass management, or simply powering the subs off)

- Right speaker only (same as above)

- Left + right speakers (leaving the bass powered off)

- Left + right + subs (by powering on the subs and using bass management)

- Subs only (by powering off the XPA-3)

- Center only (by driving left+right in PLII Cinema mode, subs powered off)

Being able to run these tests makes my setup fully functional, IMO, and will allow me to participate as a full citizen in any upcoming measurement exercises.  Now waiting on the UMM-6 mic......

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Originally Posted by audioguy 


What if anything do I now need to do to generate a test signal? Do I need to change anything in the Windows sound area??

From the output drop-down menu, select "HD Audio Output 1".  This will configure REW to output to one channel only.  If you want to test the second channel as well, open the Timing Reference Output drop-down and select the other channel, i.e. "HD Audio Output 2".  Close the Preferences screen.

On the main REW screen, open the Generator tool located at the top of the screen.  Select a signal type, e.g. Sine Wave, Pink Noise, Linear Sweep, etc.  Make sure the RMS level at the bottom left is a reasonable value, try -20dB so as not to wake the neighbors.  The Play button should be enabled (colored green).  Click Play.  You should hear sound from your AVR.

Report back forthwith.

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Originally Posted by AustinJerry 

I would like to add some comments about the purpose and direction of this thread.  These comments are prompted by Jason's answers to my list of questions.  While the answers are interesting, I am concerned that the information is too much, too soon.  There are many topics ahead of us, and we should discipline ourselves to focus on one important topic before we move on to the next.  Remember when you were taking those college courses?  On the first day of class, you received a syllabus which provided the list of topics to be covered, and the order in which they would be presented.  (I know, it's been over 45 years since I saw a college classroom, but I still remember...)

 

I think we should agree on an outline for the thread, focus on each item in order, and master it before proceeding.  An example of an outline:

 

- Assembling the hardware and software components comprising the REW kit, and mastering the techniques of configuring the components so REW is completely functional.

 

- Calibrating the mic and soundcard in preparation for taking accurate measurements.

 

- Generating and interpreting frequency response measurements.

 

- Generating and interpreting waterfall graphs.

 

- Generating and interpreting ETC graphs.

 

- Case studies:  Picking forum participants' measurements, identifying issues, and discussing approaches on resolving the issues as a team.

 

What I am trying to say is that if we try and discuss all these topics at the same time, we are going to get bogged down, and some of us may become discouraged and leave.  REW is an elephant, and we need to be the pygmies, eating it one bite at a time.... 

Agreed Jerry. By coincidence, your outline above is very similar to the one I have made for the FAQ.

I think many of us need a very basic, step by step setup guide, telling us how to connect, what to set in the REW program and the ASIO control panel, what to leave as defaults etc. So far, I seem to have got going by trial and error, but I am unsure about many of the settings in REW and whether I need to adjust them. I am also unsure about how to set the volume level (we apparently need to test at 100dB - that in itself gives me cause for a little concern) and various other things.

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Originally Posted by audioguy 

And the mystery continues. The first screen dump shows the options that REW gives me (it appears to be 2 channels). I then went to the windows control panel to set the output to use the HDMI (versus the internal speakes) and got this surprise where I can select any of the speakers shown on the diagram and have it make a sound. But how do I tell REW which speaker to select since it only gives me two choices???

You got to the same place as I did. I made the Prepro my default choice in Windows and selected 7.1 in that other 'configure' dialog (although I don't think that matters).

Then when I went back to REW preferences and selected the dropdown box I can see 8 channels.

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Originally Posted by audioguy 

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Originally Posted by kbarnes701 

You got to the same place as I did. I made the Prepro my default choice in Windows and selected 7.1 in that other 'configure' dialog (although I don't think that matters).

Then when I went back to REW preferences and selected the dropdown box I can see 8 channels.

Were you able to generate any test signals. We are soooooooooooo close but yet sooooooooo far. This has been just like the typical struggles I have always had with REW. Not EXACTLY plug-n-play

Yes - I could generate some feeble little test tones via that Windows config dialog and also, from REW, I could select any of the 8 channels shown and generate a proper test tone. By selecting a second speaker I could generate test tones through, eg, L and Subs or R and Subs etc.

I am sure you are very close. If you follow the steps in JChin's post above, that is the exact same procedure I used.

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Originally Posted by mtbdudex 

Both you are aware there is a REW online help file by author JohnM that addresses many of the subjects listed above?
I've used it countless times in my ongoing REW usage past 4+ years.

Enjoy the acoustic journey! Just remember, it's a slippery slope, meaning you have to establish goals and objectives to know when you've reached them.
Measurements for sake of measuremehnt w/o a rational plan to guide you can leave open ended questions, that is why I posted the small room acoustics background info earlier in this thread.
http://www.hometheatershack.com/roomeq/wizardhelpv5/help_en-GB/html/index.html



BTW, even though REW is "free", I've used it so much I did donate a few $ towards the cause.
I have no affilication with REW, JohnM, etc. I just believe in giving back based on my experience and how it helped me.
Each of you should consider what to do, based on your own ethics.
http://www.hometheatershack.com/roomeq/#donations

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If you have found REW useful and would like to make a donation to support further development you can do so by clicking the donation button below.

Thanks for reminding me about that link to the online help - very useful.

I will certainly make a donation if I find the program as useful as I am hoping it will be.

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Originally Posted by audioguy 

I have started REW multiple times. I have restarted my computer multiple times, I have made sure that both the mic and hdmi outputs are default and I can either get the mic to be recognized OR the 8 channels of output but not both and I have no idea why it partially works when it does.

I must say I am a bit ticked. The only reason I ordered the new USB mic and tried this all over again was because it was posted that with this new version of the software and the USB mic, it was now a plug-n-play solution, It is not one bit less complex and hard to set up than the original version where I had to screw around with the sound card and could never get consistent results.

I was a complete moron for buying into the plug-n-play concept and have now wasted hours and hours and hours and still (a) can't get the system to even setup consistently and (b) generate a single test signal. What a complete waste.

While I am sure, once running, REW is a fine tool but using the words REW and plug-n-play in the same sentence is a joke.

Can you not return the mic for a refund if you have only had it a few days?