Originally Posted by JHAz
IMO you are better off to get the sub properly calibrated and then if you want to bump it up do so. Barring a miracle, chances are the OP's sub as currently set needs a setting of less than -12 from the receiver, but it can't get there. If it's just a dB or 2, not probably a big deal, but if its more than that, things will be "out of whack" (although in a potentially pleasant way.) For me, dynamic EQ is the better way to get my bass up where it needs to be when I'm (almost always) playing well below reference. I'm also gnerally a proponent of trying the "proper" calibration for a week or so even if it initially seems bass shy. Those of us who "calibrated" by the seats of our pants in the past may have gotten used to sound that departs significantly from what the mixers and director heard. While turning down the sub to the "proper' level may decrease impact, it also may un-mask som good stuff in a soundtrack that was preveiously overwhelmed by a too-hot sub.
Again, IMO, it's best to know if you're departing from "flat" or "reference" and by how much. Once you know where technically correct is, everybody's ultimately free to choose their preference levels instead. Just better to know what departures you prefer if only so it's repeatable if you rearrange the room or get new speakers or sub . . .
+1 to JHaz explanation.
Another approach to understanding the trim calibration settings was a Q&A with Chris Kyriakakis/Founder and CTO of Audyssey as follows:
Chris Kyriakakis: Audyssey measures the entire frequency response of each speaker. The chirps are "full range" even though it's hard to hear the low frequencies in the beginning. After that the energy under the 500-2k range is analyzed to produce an SPL estimate. The trim is the difference between that estimate and 75 dB SPL.
Q: How does that work with regard to subwoofer level...does Audyssey set the bass level using the lowest measured frequency and then make cuts to equalize the other frequencies? or does it use one particular frequency like the crossover as the reference?
Chris Kyriakakis: Same as above, but the range it looks over is 30-80 Hz.
Conclusion: Audyssey sets the trims to 75 dB at the MLP (Main Listening Position) with a test tone at -30 dBfs (band limited, 500 Hz - 2kHz for satellites, 30Hz - 80Hz for sub). In case of Denon a +/- 12 dB tolerance is allocated for Audyssey. Should the trim level for the sub be out of this range the gain knob on the back side of the sub should be adjusted accordingly, i.e. trim over +12 dB -> sub gain up, while trim below -12 dB -> sub gain down.Edited by mogorf - 10/1/12 at 12:43pm