Help with REW, SPL and receiver

**gtpsuper24** · **08-24-09, 08:04 PM**

Ok heres the snippet

**brucek** · **08-24-09, 09:56 PM**

Quote:

Ok heres the snippet

The bandwidth you've shown appears fine, but can we see it with a vertical scale of 45dB-105dB and a horizontal scale of 2Hz-20000Hz.

brucek

**gtpsuper24** · **08-25-09, 01:35 PM**

So I would just load that cal file, its in notepad format, then load the spl meter cal file correct? I've tried several different ways but the rew generator doesn't work. I use left output and right output and neither worked (seperately), different cables to. I also tried different inputs on my receiver.

**brucek** · **08-25-09, 01:50 PM**

Quote:

So I would just load that cal file

Can we see the soundcard cal file graph with a vertical scale of 45dB-105dB and a horizontal scale of 2Hz-20000Hz.

brucek

**gtpsuper24** · **08-25-09, 02:37 PM**

How do I do that? Sorry I have no idea what your talking about, I just loaded the cal file and did a snippet of it thats it.

**brucek** · **08-25-09, 03:26 PM**

Quote:

I have no idea what your talking about

The soundcard calibration file that you created is located in your computer, in the folder you specified, and pointed to by REW, and is displayed when you run REW, and select the main tab to display frequency response graphs. You displayed the file up to 6KHz. I would like to see it up to 20KHz to ensure it's OK. No use carrying on if the files not good.

Start REW. It opens to the main tab. Select the soundcard cal checkbox to display the soundcard calibration file. Deselect all other checkboxes to remove the clutter..

Click the Graph Limits icon in the upper right hand corner of REW, and enter the axis of left=2Hz and right=20000 and bottom=45 and top=105dB, and Apply Settings. This changes the vertical and horizontal axis to view the entire soundcard calibration file.

Click the floppy icon in the bottom left hand corner of the graph to produce a jpg of the graph of 800 bits wide. Save it to your desktop.

Upload the file so we can see the graph....... It looks like this:

Name: soundcard calibration.jpg
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Name: soundcard calibration.jpg
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Size: 60.9 KB

brucek

**gtpsuper24** · **08-25-09, 08:01 PM**

Ok here it is, right now I can't open the jpg file you have, email account is messed up or something.

**brucek** · **08-25-09, 09:56 PM**

OK, that's fine. Be sure the file has a .cal extension and be sure it's loaded into REW.

Now carry on with your setup and measure..

brucek

**gtpsuper24** · **08-25-09, 10:36 PM**

Ok I got everything loaded soundcard cal and spl meter cal file. I'm not getting any sound/test tones nothing from my speakers. I tried pink noise, measure sweep, sine wave and I get nothing. Heres some pictures of some of the settings, I went back and looked at the previous posts and followed all the settings maybe I missed something.

**brucek** · **08-26-09, 09:23 AM**

Everything looks good, except you have your output muted.

Name: soundcard 1.JPG
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brucek

**gtpsuper24** · **08-26-09, 06:20 PM**

I unmuted the output

Now I keep getting low signal level when I run the measure heres some snippets

**brucek** · **08-26-09, 06:30 PM**

Did you set the output and input levels with the Check Levels routine?

Did you run the Calibrate routine?

brucek

**gtpsuper24** · **08-26-09, 09:22 PM**

I got the levels ok, ran the check levels and it ok'ed it fine. I ran the measure tool and nothing shows up on the graphs, the only ones that have something on them is impulse, all impulses and scope. I have my digital spl set to 70, sub gain is 50%, -7 in receiver menu. Got some more snippets

**brucek** · **08-27-09, 07:48 AM**

It isn't showing up because you didn't answer my question in my post above..

You must run the Calibrate routine after the Check Levels routine. How else would REW know where to place the trace on the graph. You can see that your trace is located at -180dB (bottom of graph).

brucek

**gtpsuper24** · **08-27-09, 10:16 AM**

So I need to run the check levels routine and then run the soundcard calibration is that correct? Everytime I start rew the soundcard cal file and the Spl file are loaded automatically, but when I run the measure tool it says spl has not been calibrated.

**gtpsuper24** · **08-27-09, 01:10 PM**

Ran the check levels again in the measure tool

**brucek** · **08-27-09, 01:52 PM**

Quote:

So I need to run the check levels routine and then run the soundcard calibration is that correct?

No, you run the CALIBRATE routine after the Check Levels routine.

This tells REW what the real SPL meter is reading.

Name: calibrate.jpg
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Name: calibrate.jpg
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You only run soundcard calibration file once and you're done forever.

brucek

**gtpsuper24** · **08-27-09, 02:15 PM**

Hows this look for a measurement? I tried to generate a waterfall but it didn't do anything. Is there anything else i'm screwing up

**brucek** · **08-27-09, 02:31 PM**

For subwoofer plots, always use the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - 200Hz) using the Graph Limits button in the top right corner of REW. Use a measurement start frequency of 0Hz and an end frequency of 200Hz. Use the appropriate target line that matches your crossover.

brucek

**gtpsuper24** · **08-27-09, 03:52 PM**

Ok got it working, thanks a lot brucek you've been awesome thanks for the help

heres some test measurements going to really do alot of reading later today.

**brucek** · **08-27-09, 03:57 PM**

The only problem in what you show is that you have the frequency response graph set to the Linear mode. You are suppose to use Logarithmic mode. The waterfall is fine.

Change this by using the icon called Freq Axis in the upper right hand corner of REW.

brucek

**spectron** · **08-28-09, 03:47 PM**

well done bruce your a star looks like theres hope for when i have a go fantastic

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