Originally Posted by bmock17
Got it. Thanks again!
As jdsmoothie suggested, the sub crawl will identify a few places where the sub should be placed with respect to the Main Listening Position (MLP) in terms of peak bass output. Audyssey XT will try and smooth out the peaks, but will not do so well with the nulls. The room dimensions and physics of long wavelength bass frequencies work against you on this.
You'll find that a single sub will struggle in getting smooth bass due to room modes below 300Hz (the Schroeder Frequency) and while it maybe okay at the MLP - just a seat away, the bass will sound very different.
Be sure to check the F3 response of the PM600 in your room as Def Tech as specs are a little bit on the generous side. A high crossover frequency set on the SR6008 (say 120Hz or more) will risk localization of the sub - where one hears both the sub and speaker. This may or may not bother you, but for some it's enough of a distraction to spoil the movie watching experience.
Once the Audyssey setup is complete, always make sub level adjusts on the Marantz SR6008. The plate amp volume level adjustment on the sub was used as an input during the Audyssey setup and modifying this may have an impact to the filters created for room correction. Furthermore, the plate amp is working in the analogue domain and not as precise as on the receiver which is working in the digital domain complete with bass management. It's much easier to get back to the default state on the Marantz SR6008 if one is fiddling around don't like the results.
Marantz SR-7009, Oppo BPD-93, MTV 7000D, aTV, Harmony Home Control remote, KEF E301+T101, MiniDSP (2x4)+(10x10HD)+(DDRC-88A), Emotiva 2xXPA-5 (Gen2), Rythmik 2xF12G+2xF8, HiMedia Q16, LG 55EC9300.