I just bought a new Paradigm Servo 15 v2 last week and I have some questions for you experts.

I have a Denon 3803 receiver which I use to calibrate all channels with the test tone function. It works great for the speakers, I get accurate DB readings on my radio shack SPL meter, but with the subwoofer the needle on my analog SPL is always dancing, 3 to 6 db, is that normal? Does this have something to do with my room response?

Another thing, I have tried my AVIA disc for calibration AFTER I calibrate with my Denon's test tone. The main speakers where calibrate ok but the sub test tone coming out from the AVIA DVD is way lower than the Denon test tones. I have reajusted the output but now the bass is way too loud, so I put it back to my Denon's settings.

What should I use? My Denon test tones or the one on the AVIA disc?

I played with the phase too, but didn't ear any difference...

help please.

Base waves are very large and the variations you are reading have to do with the way the sound waves bounceh around the room (cancelling and reinforcing each other). Just try to take an average.

The variance in your test tone readings may have to do with the differing frequences used by the tone generator. If there is a frequency which your subwoofer is emphasizing, one set of tones may read higher than another set of tones which don't put out that frequency, and this happens more easily with bass tones than the main speakers. Also remember that the Radio Shack meter reads a bit too low for bass tones, so if the reading is say 1-3dB too low on the meter, it is about probably about right.

I'm sorry, but it's too difficult to diagnose long distance. I'm afraid you'll just have to ship me your Servo 15v2 for some extended analysis.... may take up to a year or more, we can only hope.:p

Seriously though, the needle jumping around is fairly normal. It's related to the way that subwoofer frequency response can be peaky.

The Denon is probably calibrating the sub level pretty close to even with your mains, but it looks like it's low when you measure it with the RadioShack SPL meter because the RS meter is about 2-3db insensitive at very low frequencies in the subwoofer range.

I'd try just adding 3 db to whatever the Denon sets the sub level at and try that out for a while.


Tim

that makes sense.

What about the phase control knob? I played with it and I don't hear much difference. I think I must turn it until I hear the loudess bass, is that right?

Yep, you can get phase pretty much right on by just adjusting it so that you get the loudest bass at the seating position. If you do it that way, it helps alot to have another person helping you. And, go by the values on the SPL meter, not your ears.

Tim