Help please - Calibration Trouble

**zorax2** · **04-24-06, 06:51 PM**

I've got the Creative Labs USB MP3+ sound card. I did the calibration which was flat 20 - 20K. When I ran the calibration check suggested by John on the left channel, the response did not match. I've attached a graph. I'm not sure what is going on.

Additionally, I've attached a graph of my sub response. Is this also out of whack - no peaks or valleys whatsoever? The sub is in an extremely large area. Whereas in my former home the sub pressurized the room and could punch me in the chest, I would need about 6 of these or more to pressurize my current space. Perhaps that is influencing the results. Any thoughts?

The initial results seem to indicate I do not need to use any equalization but I find this hard to believe. Thanks in advance for your help!

**zorax2** · **04-24-06, 06:54 PM**

OK - my graphs didn't have labels. The top graph is that of the soundcard measured on the left channel.

The bottom graph is of my PB12-Plus/2 sub.

I didn't catch the fact that they were the same until now. Weird - I wonder what's going on?

**Sonnie** · **04-24-06, 07:19 PM**

JohnM should be available soon to help you with this.

**zorax2** · **04-25-06, 10:07 AM**

I've kept trying to figure this out without much luck. I've noticed that for whatever reason - the measured response of the left channel (subwoofer plotted in Red) is a mirror image of the Radio Shack microphone calibration (plotted in black)that is applied.

I noticed that if I cleared the microphone calibration, the test of the left channel matched that of the soundcard with flat response. If I enabled the newrs.cal file, I ended up with the inverse plot shown.

I've also attached my soundcard debug file.

**zorax2** · **04-25-06, 10:09 AM**

The soundcard debug file was 25k so it didn't upload.

**Sonnie** · **04-25-06, 10:21 AM**

I'm not sure where JohnM is... I suspected he'd have been by here already. He musta got hung up somewhere there's no computer.

Try uploading that debug file now... I increased that extension size limit to 32K... assuming it's a text file. If not, let me know.

**zorax2** · **04-25-06, 10:52 AM**

Duh - I just read some more information at the Next Level forum and double checked my settings. For some stupid reason I had my input set to wave rather than LINE IN. Oops!

**zorax2** · **04-25-06, 12:22 PM**

Hopefully - here is the soundcard debug file.

**JohnM** · **04-26-06, 09:59 PM**

You need to repeat the soundcard cal with Line In selected as the input. To check the cal, first clear the mic calibration data as when you are connected in loopback there is no mic, so you end up with just the inverse of the mic cal if you haven't cleared it first. After the check, load the mic cal file again for your actual measurements. I'll update the help files to address this.

**zorax2** · **04-28-06, 11:10 AM**

John - thank you for confirming the reason I was having the problem. I thought there was some type of quirk once I realized that there was an inverse curve relationship going on.

I'm sure my calibration check will work just fine now.

Thanks again for your help!

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