Yes - your info is most helpful... thanks again!
I'm thinking more and more that I wish I would've gotten the Laramie Sport I'd been looking at, rather than this Limited Longhorn my wife found... it would've been cheaper, had the Alpine system, and would've been a lot less 'Yee-Ha' than the rodeo-themed interior I now have (I am very much NOT a Texan, despite living in San Angelo). Now, having said all that, I really do love the truck and have a few plans for making it more 'mine.'
Yes, I was talking about the storage bins under the back seat. The MTX box took away those bins on my 2012, so I'm happy to have them back with the '21... but I'm willing to give up one of them, if that's where the Hideaway (or whichever one I go with) happens to wind up residing. Under the driver seat would be optimal, but I need to scope it all out to find the room to make a home for that add-on powered sub.
Good info about PAC gain control knob - it's nice to know that if the powered sub doesn't come with its own, there would be an option. Having that gain control will be huge for me. I listen to a LOT of different kinds of music, so setting the B-M-T (EQ) to an overall workable curve is the best I can do, but a lot of tunes (like most of the '80s & early '90s rock tunes) just don't have a lot of bass or fullness built-in, hence the gain control knob - dial it up a bit for those tunes, and back down again when something newer with better engineering and production comes on.
I ain't gonna lie: as well as the H-K subs handle the better-engineered tunes, I'm not entirely unhappy with the system. If there was just a way to better fine-tune the EQ curve and adjust the gain for the subs on-the-fly, that would be awesome. I've been tossing around an idea of pulling the H-K subs out of the system's control, wire up separate amps (with their own gain control) and place them back into the mix. In theory, that would actually accomplish what I'm hoping to have, but I'm thinking that would be too much of a PITA... most likely ruining the spiritual creaminess of rest of the H-K system and make things worse (for instance, I'm sure there's some noise-cancelling going on, and the sound processor would probably do some weird stuff to compensate). I'll just stick with an add-on - my MTX was 400w RMS, and honestly was just about all I needed with that system. Most tunes ran with the gain around 3-4... some up to 8-ish, and a few even got bumped down to 1 or so. That's the flexibility and augmentation I'm looking for - just keep 'em all filled in as needed.
Some people would suggest just using Sirius (since the recording levels are already optimized), but in all honesty I ran through everything one day, and just like the first few times I played with Sirius in other cars, "there are a 1000 channels, but nothing I want to listen to."
Thanks again for the info and insight!