How do you get the cans down to the drywall facing? Or did you guys use the IC remodel cans?

You need to install a couple of sleepers.
(Here's from the magic decoder ring...)
Attach 3/4" plywood plates to the joists which are installed to terminate below the joists, even with the back side of the drywall.

However, since you're going to all this sound isolation effort, it would be better to visit Ted's site at www.soundproofingcompany.com and review the destructions for building an isolation box for your cans. This willl allow lowering the cans plus allow you to maintain your isolation levels.

Do you have a direct link? I couldn't find any articles on building isolation boxes for recessed lighting on the site.

Thanks,
CJ

It's actually a link under 'Library--Articles--Flanking' all the way at the bottom.

http://archive2.avsforum.com/avs-vb/showthread.php?t=654719

Many people here have built these boxes with similar techniques. Search AVS for "backer boxes" and you'll be able to see plenty of examples.

DO the cans really need to be that low? I notice that the inserts in mine look they they can be adjusted to fit tight to the botom of the drywall and still attach to the inside of the can. The inserts just have a bent metal "clip" that friction fits to the inside of the can. I have a couple of a different design that have the spring clips and I'm thinking a little paper clip extension ought to do the trick.

It's actually a link under 'Library--Articles--Flanking' all the way at the bottom.

http://archive2.avsforum.com/avs-vb/showthread.php?t=654719

Many people here have built these boxes with similar techniques. Search AVS for "backer boxes" and you'll be able to see plenty of examples.

Thanks- I was aware of the back box thread on AVS, but was wondering about the adjustability that Dennis alluded to in the article on Ted's website. However, it appears that this just links back to the AVS forum's thread. I don't need the adjustability myself, I was just wondering.

CJ