Adcom Gia 555ii amp and gfp 565 preamp

Sounds like a nice set up! For the longest time I had the same issue with subs. They filled in the lower regions ok,but they always sounded like something wasn't quite right. I finally connected them directly to my amp using high level inputs,and SHAZZAM!  They now blend very well. (At least to my ears)

I am going to try that,  had been thinking about it but hadn’t got around to it yet. I have to try that. Trying to get the best sound on a junk budget. 

Do you know the environmental condition of the storage area?  If conditioned were 70 degrees +or - a bit. If so, I would do a few things first.  Open the cases and perform a visual inspection of each device.   If the capacitors are swollen and leaking material, this would be bad. Now, if you only find dust and age related debris, plugged that puppy in and rock.  

None of the above is based on a Electrical Engineering Degree, just years of "Get It Done" and are you kidding "it Worked".

Inside climate controlled storage in boxes. There literally is not even any dust inside and I looked at the four main capacitors on the amp and they seem to be holding in there but there is no doubt in my mind they should probably be replaced on age alone at some point. Haven’t looked at the preamp yet.

Also got a gsa 700 in with the bundle but I am pretty much a 2 channel stereo guy.