I used the audessey calibration to set things originally, but I find that I have to increase the input to the center channel sometimes as high as +6. and this woks pretty well for some things. During calibration the sub ended up a few degrees less than straight up, call it 45% gain.. This is often too much I find so I reduced this input via remote call it -10 so that is what I have going on and it works for me at this point. (I've even just turned the gain down to like 33% manually on sub) so I wouldn't say I prefer bass heavy sound. Its awesome except when its getting in the way of hearing other stuff. Note: the sub isn't far from where I sit, say 3 ft, front stage is like 15 ft, so this could be a big part of it. Sub was on front wall to the right of the LCR, but I moved it to the right rear (3 ft from me) and re-calibrated it. The move was to make room for other stuff in the room and aesthetics. Acoustically I don't prefer it but I'm making due.
All I'm getting at with my original question about future options is that it seems like my sub has a lot more head room and the center/(front stage) is often lacking. sometimes i wish more content was run through the other fronts. Seems a ton of content runs (like 80%) through the one center speaker.. Is what it is!
Depending on what I'm watching I'll add 4 to 6 dB to my center channel so to me that's pretty normal. As for your bass It almost sounds like something is wrong. If it's set correctly that sub should not be drowning out the other speakers. I have 2 of them and they didn't overpower my bookshelf speakers or my little
DefTech ProMonitor1000's (which are currently part of a small stereo setup in my office).
One thing I just now discovered while navigating menus is when I went into "Subwoofer Level Adjust" and turned it on things got boomy and overpowering. If you have Denon/Marantz you could try going into the menus and make sure it is "Off". When I adjust my sub levels I go in with the "Option" button, then "Channel
Level Adjust" and do it from there. I never use the sub adjust under the "Audio" menu and leave it off.
I'm assuming you're auto calibrating and setting levels with... was it Audyssey XT32? I forget and started typing already and don't wanna go back, lol. Also, I'm sure you saw it, but just in case, Hsu does recommend calibrating in sealed mode with both ports plugged and EQ set to 1. The gains for both of my subs are ~25 - 30% and my receiver set the trim at -9.5, which is a good spot to be. Then I added another +5 dB to each and they're smooth and musical, not boomy or overpowering at all.
You did mention location and that can have a huge impact on what you hear. If you're close to a wall or in a corner things can get boomy. Oh! Have you tried plugging one or both ports? That's one of the pluses with the VTF (Variable Tuning Frequency) series. Gives you some flexibility and options.
I know you said it's sounding pretty good, but I'm still getting a vibe from you that things could maybe be a little better and believe me, I can relate with that. I wanna help you get your system dialed in so it puts a smile on your face every time you use it! If I think of anything else I'll pop back in and let you know. Sub position is probably gonna be the key so you could try finding another spot, but check on that sub adjust I mentioned above real quick too. When I turned mine "On" it was enough to make me cringe, lol.