posted by Edward J M over at HTF...
There are common set-up errors that could be causing some problems. Double check all of these things before you try to recalibrate:
In the AVR:
1) All speakers set to small.
2) Crossover set to 80 Hz.
3) Sub set to on/yes.
4) Subwoofer Remix or LFE + Mains set to off/no.
5) Dolby Dynamic Range Compression Circuit set to off/no.
6) LFE (0.1) channel level set to maximum (i.e., unattenuated) value (if the AVR has the capability).
7) THX (or any other) bass limiter circuits set to off/no.
8) Subwoofer channel level to -5.
In the DVD player:
1) Output set to bitstream (digital output via the digital coax).
2) Dolby Dynamic Range Compression Circuit set to off/no.
On the subwoofer:
1) PB2 to all ports open (we can try 20 Hz tune later).
2) Tune switch to 25 Hz.
3) Crossover switch to off.
4) Set the phase to 0 degrees initially unless you have the capability to evaluate the FR of the system.
Avia is true Dolby Digital and uses the speaker channels for sub calibration and therefore allows the speaker channel in question to contribute bass to the subwoofer tone.
I have found that the amount of bass each speaker contributes to the sub tone is highly dependent on its room location, its inherent bass capabilities, its proximity to the subwoofer, and the xo you have selected.
For example, the left main channel in my system is several dB higher than any other channel on the subwoofer tone. If I selected the left main channel for sub calibration, it would result in undercalibration of the sub.
The best way is to run the Avia sub test tone for each speaker channel and note the results. Pick the one that seems most representative of the average and go with it for final sub calibration.
Also, a good way to evalaute the effect of the phase control when using Avia is to run the sub calibration tone for the speaker closest to the subwoofer and try the phase at 0 and then at 180. Observes what happens on the SPL meter. Usually one setting will be considerably higher than the other, indicating the subwoofer and the nearest speaker are the most "in phase" at that phase setting. This may not be completely desireable from a smooth FR standpoint, but it can help you understand the effect of the phase control, since Avia does rely on redirected bass.
Keep your sub level in the pre/pro around -5 to minimize pre-out distortion levels, and adjust the sub volume at the PB2.
While bass tastes will vary, most prefer the sub 2-3 dB hot for HT, and flat for music. Because it is C-weighted, the RS sound meter reads about 2 dB LOW on the typical subwoofer rumble tone.
So an average reading of 85-86 dB on the meter is about 87-88 dB in reality - or 2-3 dB "hot". This would be a good starting point for HT. If it's not "hot enough", crank it up another 2-3 dB; the PB2 can take it.
An average reading of 83-84 dB on the meter is about 85-86 dB in reality - or about "flat". This would be a good starting point for music.
The above assumes you are using 85 dB with Avia to calibrate to Reference Level. You can use a lower level of course (like 80 dB as you stated above). I just find using 85 dB and Master Volume to 0.0 easiest.
If you retune the PB2 to 20 Hz, bump the sub level in the pre/pro 2-3 dB (over the 25 Hz tune) to compensate for the loss in sensitivity.