Best $4000-$5000 loudspeaker

How about Merlin VSM-MM's (I found mine for $4500 as demos)or MX's (might be able to find them used for around $5,000-$5,500).

They extend down around 28 with BAM, work well in an average size room, and can be enjoyed at low to moderate levels.

Swklein listed most of the speakers I would have included. As an owner of the Vandersteen 3A Signatures, I can highly recommend them -- they compete very well with speakers costing up to $5000 (MSRP). The one other speaker I'd add to the list is the Magneplanar 3.6's, which are a superb speaker if you have the right room for them, and a fairly powerful amplifier (200 wpc minimum).

For new, I like the Focus Audio FS788 and Amphion Xenon.

Merlin VSM-MM is perfect for your requirements!!

Check out the new Hyperion HPS 938. Rave reviews from all magazine's reviewers and agon alike.
Good luck,
Tim