Originally Posted by kbarnes701
While I had the OM out, I did this experiment, with Audyssey off and then on. Settings are the same as for the OM graphs in my earlier post.
The blue line is with Audyssey OFF of course and the red line is with Audyssey ON.
While the red curve is clearly much flatter, can anyone offer an explanation of why Audyssey seems to be bringing the lower bass down so much? More than 5dB down at 20Hz and about 10dB down at 15Hz. DEQ is off of course and may well compensate when it is on, but it just seemed odd to me.
You got a pair of Submersives? I didn't know. Congratulations! ;)
Seriously, I think the response curve looks pretty good. Looking at the gradual dip going to the left, I looked at my most recent measurement, and I am seeing something similar, but perhaps not quite as pronounced.
Whether this is intended by Audyssey would be difficult to tell, given that we know little about its inner workings. Before the recent measurement in my system, I did play with an adjustment on my Hsu ULS-15 subs called "ULF Trim", which has a variable setting from 16Hz to 50Hz. Here is the effect of this adjustment (with Audyssey off):
Since the 50Hz setting produced what looked like the flattest response, I used this setting before re-running a Pro calibration. It's entirely possible that if I had used a different setting, the post-calibration bass response might have been flatter. However, I get tired of re-running Pro calibrations to tweak minor differences that I can't really hear (especially because a bug in the 4520 causes calibrations to take twice as long), so if I have a different reason to calibrate, I might change this setting.
Slightly OT, I have been green with envy ever since you installed the Submersives. I'm now trying to devise a plan to sell my ULS-15's and replace them with a pair of Submersives. I just need to read the info in the AVS Submersive thread to see which model would suit my perceived needs (space is not as much of an issue as it was for you). As someone once said, you can never have too much woofage.....
Back on topic, I spent several hours recently looking at every possible tweak to see if I could improve my bass response, especially the dip 90-100Hz, and the smaller dip around 50Hz. Treatments are no longer the issue, IMO, because I have eight 2'x4' bass traps in every available corner of my listening room. The final frontier is to see if the Curve Editor can be leveraged to provide some improvement. Thanks for sharing your experience, and for ruining the rest of my day... ;)