Order of Importance with setup?

[sploo]

OK. Well, I don't have the machine I was using for ETF at the moment, so I can't compare a soundcard only reading.

What I would say is that, a PC is an electrically noisy environment, and it wouldn't surprise me if you got a some noise in the reading.

Also, the level of noise in the pics you posted is way below what you're going to see if you've got reflections in the room, so it shouldn't affect your readings.

Connect the PC to your amp and run a full frequency sweep. You may need to have a few tries - tweaking your amplifier volume and SPL meter sensitivity dial (I'm assuming you're using the RS unit).

If you can get yourself a set of graphs that look even remotely like the ones I got (i.e. 'something' is happening) then post them here and I'll take a look.

 

[Vaughan Odendaa]

Thanks ! I also downloaded REW (Room EQ Wizard). I also get noise in the results. But in ETF, the results are bad.

I will try to post some graphs with room measurements but I fear that my poor sound card FR is going to mess up the readings. What concerns me is that even after changing the sampling from 44 to 48, it did not clear up the noise at the help file suggested it would. It made almost no change.

That worries me, to be honest.

--Sincerely,

 

[Ethan Winer]

Vaughan,

> This whole time I've been struggling to get a good flat line with no or little noise. <

I've never run ETF with both channels looped, so I can't say if you should have that noise or not. Most sound cards these days, even cheap ones, have acceptably low noise for music (80+ dB), and you need only 50 dB or so to do a decent room measurement. So here's what I suggest:

Use the microphone to record yourself talking at a normal level from about two feet away. If you don't have a "real" recording program, use the Windows Recorder. Set the record level so the peak reading is between -10 and 0 dB while you speak. Then play it back and listen. If the recording sounds basically clean and has no obvious or excessive hiss, then your sound card is fine.

--Ethan

 

[Vaughan Odendaa]

So I just connect the SPL meter into the right line level (or is it microphone) and start talking. Correct ?

I spoke with Doug (from ETF) recently, and he suspects that it could be my sound card. He thinks that my card has a very old chipset.

I'll try to record something and I'll check back. Thanks.

--Sincerely,