Testing speakers ?again

[martyh45]

The last piece (hopefully) of my testing gear will be shipped out in the next couple of days and I am looking for some advice on how to start measuring.
So far I have assembled ?.
Dedicated XP pro laptop
M-Audio audiophile USB outboard card
M-Audio Audio Buddy Mic Pre
Low power SS amps
Dayton WT3 tester
On the way is a calibrated Dayton Mic
I have Holm impulse installed and got what looks to be a valid calibration of the soundcard through the ASIO driver at 48kHz duplex (after a day of screwing around) WT3 looks to be working too, getting normal looking and repeatable impedance curves anyway
I?m not really confident of setting the gates in Holm at this point so I plan on measuring outside. The one thing I really want to measure is 802-8g on a 32B just because I have never seen measurements posted for this combo.
So?there it is any advice you can share will be appreciated.

[Panomaniac]

Sounds like you are well on your way. I don't use the gating, just take my chances with the smoothed response. Doing measurements near and far and using a little brain power can go a long way.

Hint: Double check your sweeps with the MLS square noise measurement. I find it better in the bass, anyway. I usually have to restart the audio stream is switching from sweep to MLS or back again - or I get glitches.

Don't worry too much about the sound card calibration, they are usually so flat that it doesn't matter. How did yours look? Mic calibration is important, so be sure to load that.

The WT3 is super easy to use. Just be sure the room is quiet. Keep the woofer vertical and away from reflections.

[martyh45]

Thanks for the reply. The card looked flat with low distortion after I got it working right. I had to disable some other audio stuff to make it work though. When I first started I was getting bizarre spikes all across the audio band and high distortion. Do I need to include a capacitor to protect tweeters or can I set the sweep frequency high enough to prevent damage?

[Panomaniac]

Good question. If you use the "High Pass" down on the lower left, it should limit the sweep.
But be careful and start with a cap and low levels. I've done a lot of tweeter testing with HOLM and so far, not hint of trouble.

You also want to be sure your amp has no, or very little, DC offset. If it has an output transformer, no worries.

Yes, there is an amazing amount of junk in Windoze that will interfere with the audio. Tracking it all down is a pain.