REW Forum

**Vaughan100** · **03-04-08, 03:05 PM**

Hi there,

It's been some time since I last posted. The last time I gave up with REW because my sound card was simply not up to the challenge. However I downloaded the latest sound card drivers and things have changed.

The graph looks like it shows in the help file. Now I'm getting somewhere ! I saved the calibration file and went step by step to recalibrate for a flat line and I still don't get a flat line.

Now I need your help. I need to get that flat line. Thanks.

--Regards,

**JohnM** · **03-04-08, 04:51 PM**

Soundcard cal looks fine. You need to press the Measure button on the main window (the image of the subwoofer and the mic in the toolbar) to make the check measurement, the Measure... button in the soundcard settings just re-measures the soundcard.

**Vaughan100** · **03-04-08, 11:07 PM**

John, in your help file it tells you how to get a flat response from the sound card. I unchecked the C-weighting box and got rid of the cal file and then remeasured and the graph looked exactly the same.

According to the help file, once you do this the graph should be ruler flat. So I just want to know that I'm doing this right.

I did as you suggested and pressed the measure button. Graph looks like this :

--Regards,

**Vaughan100** · **03-04-08, 11:20 PM**

Right, I unchecked the C-weighting function and redid the test. Graph now looks like this :

Tell me what you think. Thanks !

--Regards,

**JohnM** · **03-05-08, 03:58 AM**

That looks OK, can ignore the noise above 20kHz and carry on with checking levels and calibrating the SPL rerading.

**Vaughan100** · **03-05-08, 10:47 AM**

John, so can I proceed to the next stage and leave the sound card settings ? Otherwise this is a major step for me.

I assume once I've calibrated the SPL reading then I can actually start measuring my room response ? At the moment, I sold my SVS PB10 ISD and have ordered dual MFW-15 subwoofers.

Can I measure my room response without the subwoofer ? I'm using largish bookshelf speakers at present. Really would like to see what the decay times are like in my room.

Thanks again John !

--Regards,

**JohnM** · **03-05-08, 11:06 AM**

Sure, go to it.

**Vaughan100** · **03-05-08, 12:20 PM**

John, could you please explain to me how to get the SPL meter wired up to get measured ? And also how to get REW to measure without a subwoofer. What do I need to do ?

Thanks.

--Regards,

**Vaughan100** · **03-05-08, 12:22 PM**

Thanks again for helping John. I really appreciate it.

--Regards,

**JohnM** · **03-05-08, 03:32 PM**

Connection details are in the Getting Started section of the help, the SPL meter line output is connected to the right channel of your soundcard's line input and the soundcard's left and right outputs can be connected to an input on your processor, e.g. "aux". To measure either of your front left/right speakers alone just disconnect the other one. Make sure the processor is not in a surround mode, set it to "stereo" or similar.

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