Sound Card Calibration

**aceinc** · **03-18-07, 01:06 PM**

I want to use REW for Sub tuning. I have a Toshiba Tablet with a Realtek audio card built in. I downloaded the latest version (4.0) of REW. I ran the calibration, and the test afteward, and I get the attached graphs.

The raw test shows the freq response rolling off pretty high, and the compensated test still shows a curve that looks unusable for sub testing.

Am I doing something wrong, or do I have a crappy soundcard?

**brucek** · **03-18-07, 01:25 PM**

Quote:

The raw test shows the freq response rolling off pretty high, and the compensated test still shows a curve that looks unusable for sub testing.

The raw test with the loopback cable is the purple line and looks perfect.

You're right, the soundcard ain't great, but the soundcard calibration file (dotted line) compensates and gives a flat response ready for testing.

Many people use an external USB soundcard when they have a laptop for REW.

Once you take a measurement, be sure to post measurement graphs for subs using a vertical scale of 45dB to 105dB and a horizontal scale of 15Hz to 200hz.

soundcard-test.jpg

brucek

**aceinc** · **03-18-07, 02:54 PM**

Sorry about that, I guess I was reading the graph wrong. I thought the dotted line was the compensated graph.

Paul

**koiman** · **04-15-07, 07:46 PM**

bruchek,
I am still trying to calibrate my Sound Blaster Live 24 I hooked up the line from my mike in to the speaker out and ran a sound card calibration and this is what I got any ideas.
Thanks,
Leon

**aceinc** · **04-15-07, 08:13 PM**

I'm sure brucek will have a definitive answer, but I believe the problem might be related to software that "enhances" the sound. Look in your system tray (bottom right) and see if there is any icons related to the sound card other than the volume control, if so turn it/them off, or exit it/them, and try again.

Paul

**Otto** · **04-15-07, 08:14 PM**

Quote:

koiman wrote:

bruchek,
I am still trying to calibrate my Sound Blaster Live 24 I hooked up the line from my mike in to the speaker out and ran a sound card calibration and this is what I got any ideas.
Thanks,
Leon

Hi Leon,

You want to use "line in" rather than "mic in" on your soundcard.

**MakeFlat** · **04-15-07, 10:27 PM**

Leon, check that the CMSS light on the Sound Blaster is OFF. Also in the Creative Console named EAX, check that the sound effect option is unchecked (or not ticked).

**koiman** · **04-15-07, 11:11 PM**

Quote:

Otto wrote:

Hi Leon,

You want to use "line in" rather than "mic in" on your soundcard.

otto,
When I use the line in I don't have enough power to attain a reading.

**koiman** · **04-15-07, 11:12 PM**

Quote:

MakeFlat wrote:

Leon, check that the CMSS light on the Sound Blaster is OFF. Also in the Creative Console named EAX, check that the sound effect option is unchecked (or not ticked).

CMSS light is off.. EAX is set correctly.
Thanks,
Leon

**Otto** · **04-16-07, 07:47 AM**

Quote:

koiman wrote:

otto,
When I use the line in I don't have enough power to attain a reading.

Hi there koiman,

Well, you generally want to use line in for the way we have things set up here. If you are using speaker out to line in, you should definitely be able to get a reading. Check your sound card settings via the speaker icon in the task tray. Are all levels up (both the speaker output as well as the line in knob)? Nothing muted (probably not, else I'd expect you to get nothing).

Similarly, in REW's "Settings", you can control the levels for the soundcard on the appropriately-named "Soundcard" tab. Make sure you have selected the correct inputs and outputs for the soundcard being used, and then ensure that the levels are at max (you can adjust them down later, if need be).

After all that, redo the soundcard cal and see what happens. You should definitely be able to get correct levels using speaker out and line in with a loopback cable.

What's the rest of your setup like? Specifically, during normal measurements, how will you feed the input of your soundcard? Radio Shack SPL meter? Other SPL meter? Mic and preamp? Mic only?

Thanks! Good luck!

**koiman** · **04-16-07, 09:48 AM**

Otto,
I checked all setting that you told me to check.. Sound card input set to 1.000 surround mixer master control set to 100% and when running the line in to speaker out I get a maxium reading on input of -64.3 way to low to run the sound card cal.
Thanks,
Leon

**brucek** · **04-16-07, 11:14 AM**

Post a picture of your mixer settings.

Are you using stereo to mono adapters on your soundcard?

brucek

**koiman** · **04-16-07, 08:38 PM**

brucek,
I am using the stereo to mono plugs like you told me to... I don't know how to post a picture of the Surround Mixer but here is my readings.

Master Control .. Volume 100%
Wave.. 100%
MIDI.. Cancel
CD Audio.. Cancel
Line in/ Mike.. Cancel
What U Hear.. 100% (Record)
This set up is just like the one in the tertorial.
Thanks,
Leon

**Otto** · **04-16-07, 08:58 PM**

Quote:

koiman wrote:

brucek,
I am using the stereo to mono plugs like you told me to... I don't know how to post a picture of the Surround Mixer but here is my readings.

Master Control .. Volume 100%
Wave.. 100%
MIDI.. Cancel
CD Audio.. Cancel
Line in/ Mike.. Cancel
What U Hear.. 100% (Record)

What does "Line in/ Mike.. Cancel" mean?

In my case, I need line in...

**koiman** · **04-16-07, 09:06 PM**

In the source box there is a line in / Mike setting.. the speaker at the bottom of the line has a X in it just like the the original picture in the set up section of the instructions for the Sound Blaster Live 24
Thanks,
Leon

**Otto** · **04-16-07, 09:14 PM**

OK. Gotcha. I found that thread about SB 24 setup. Did you see this post? I see that you listed "What U Hear", but they're saying to find the Line In in that box. I don't have that soundcard, so I'm not sure how it works, but that might be part of it.

**koiman** · **04-16-07, 09:15 PM**

I think I have figured out how to post a picture of the Surround mixer.
Thanks,
Leon

**Otto** · **04-16-07, 09:16 PM**

Yep. Now can you select that little "ear" icon by the "REC" and drop it down to select "Line In"?

**koiman** · **04-16-07, 09:52 PM**

Otto,
Ok.. I finely got it to work instead of having the Input Device on the Sound Card set to line in/Mic in, I changed it to What U Hear and it ran a perfect line. Thanks for all the help I have been fighting this for a week now.

Thanks,
Leon

**Otto** · **04-16-07, 10:03 PM**

Hmmm, that's interesting.

So where is that "Input Device" setting actually located? You said it's on the Sound Card, but I'm not sure what you mean -- on the hardware device itself? You changed it from "line in/mic in" toWhat U Hear? Is that telling us that there are two places that must match for this thing to work? And the previous post I liked to just happened to have it the other way around? What if you set them both to "line in/mic in"?

Or am I missing something?

**brucek** · **04-16-07, 10:14 PM**

Quote:

Ok.. I finely got it to work instead of having the Input Device on the Sound Card set to line in/Mic in, I changed it to What U Hear and it ran a perfect line

I'm afraid your perfect line is an illusion. When you select What U Hear with that soundcard it turns on the internal loopback of the card. The output loops directly back to the input and gives a perfect line. You can't measure anything though.

Return the settings to mic/line in as shown in the sticky thread... Re-read that entire thread and set it up the way it describes and it will work..

brucek

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