Here are a few thoughts that might help and won't cost much.
First I have the LW-1 pre (w/DACT attenuator) and AZ Matrix Ref interconnects between LW-1 and power amp (McCormack DNA-1 r/a-gold). I don't currently hear boominess per se, but I have in the past heard the bass to be a little loose...I've always attributed that to my Vandy 3A sigs though. Here are a couple things I believe helped.
Thought #1 (isolation): A local audio buddy had me over and we were listening to his system and we pulled out a trio of DH Squares (by Golden Sound) that had been under his DAC. Suddenly and to my amazement, the bass became bloated and loose. I thought I understood the importance of isolation, but the difference here floored me. He has a decent rack, cones, lead shot, etc. He couldn't put the squares back quick enough. Since that experience I have added two sets of squares (6 in all) to my DAC and transport (w/o cones). It has tightened things up a lot. List price of these are $10 each. I'd recommend trying a set under different components. BTW, I'm using a polycrystal rack and still hear the differences. The bass gets tighter and more defined with an overall relaxed, natural sound. I have two more sets on order to try under my amp and LW-1.
Thought #2 (CD polish): Another thing to try regarding your comment on some CD's sounding unforgiving is Vivid from WalkerAudio.com. I was using the Mikro Smooth from Mapleshade to clean my CDs. The same buddy gave me a little Auric Illuminator to try and there were improvements. Then he tried the Vivid and "had" to send me home with a little to try. I now use it on all CDs with excellent results. Again, I sat listening in disbelief. Kinda felt like a newbie...switching cables for the first time. Doesn't even sound like "digital". BTW, I did try some car polish (Zaino - great stuff) but didn't do much for the CDs. Price is $65 shipped when purchased direct with a money back guarantee. A must try!
Thought #3 (A/C receptacles): To smooth things out, try a single FIM receptacle...$60. See http://www.gcaudio.com/Archives/summerfall2001.htm. IME, this is an accurate review.
Regarding speaker cables, I use the AZ Satori's and while I haven't tried other ones since I retired my AQ's (too short in new setup), I can recommend them with confidence.
Power cords...'nuf said.
Here is my system for reference only: http://cgi.audioasylum.com/systems/837.html
Enjoy and good luck!
-- Greg
YMMV, IME, IMS, etc.