Anyone use a sub with 2-channel?

steveinaz

I'm pretty sold on the idea. I'm imagining some Linkin Park power chords thru an SVS.....:D

Dr. Spec

When you're adjusting the Phase, what are you listening for to get optimum sound integration?

I'm running about 20 FR sweeps via my test rig. I go in 10 degree increments. Easy and fast with the QuickSweep function on TrueRTA. 110 degrees is perfect in my rooom; the curve just flattened out like magic.

PolkWannabie

Doc,

What kind of tools are their for measuring stuff like this outside of using an SPL meter and without laying out a bunch of cash ?

Is this what you are referring to ? http://www.trueaudio.com/rta_abt1.htm ... What other equipment is needed ? A certain kind of mic ? etc.

Dr. Spec

You need:

1) The software ($100).
2) A measurement mic ($50).
3) A mic pre-amp ($70).
4) An audiophile grade PC sound card ($100).
5) Professional FR calibration of the pre-amp and mic ($50).
6) A sound level calibrator for the mic ($350).
6) A handful of interconnects and adapters ($50).
7) A firm grasp on manipulating the log10 dB scale and calculating THD.
8) A boatload of patience for a very steep learning curve.

I was fortunate enough to already have a sound level calibrator, so I didn't pay for that part. But if you are just getting started, you'll need to buy one. It can be used to calibrate SPL meters and mics - it generates a test tone at a specific SPL when the nose of the mic is placed into the receiver cup of the calibrator.

Doc

PolkWannabie

Thanks for the info ...

Although I'm sure this methodology is what's needed to be totally accurate, it appears to be more than I have the patience or need for.

Short of that is it just an Avia disk and a SPL meter ? or are there other viable methods in between some where.

tryrrthg

the cheapest route is a CD with test tones and an SPL meter, it just takes a LONG time to run through them and then plot graph of your results. It's a pain, but with some time spent it can be very rewarding...

here are some test tones to download and burn to a CD

http://www.snapbug.ws/sinewaves/

Dr. Spec

Make sure to use the correction factors for the RS meter. They aren't exact, but they are far better than not using them.

Also, the Behringer ECM8000 mic I use is a steal for $50 - nothing else comes close as a measurement mic for the price. But aside from that, a pro grade mic (like LinearX) with say 160 SPL capability @ 2% THD will set you back about $400.

Add auto THD capability from software like SpectraPlus, and you're looking at $800 vice $100.

And if you go full bore pro grade test rig all the way - count on $5000+.