Speakers or Amplifier

Why not go with a set of subwoofers? SVS, JL, Martin Logan ... just to name a few have excellent products. Make sure that it's a sealed unit with adequate power. Subs have come a long way and may really improve even a very nice system such as yours.

Just a thought, but why not try different speaker cables. I am not discounting yours, but sometimes a different cable cab make a big difference in sound presentation. Try the lending library at the Cable Company, provided that 8 feet will work for you. I think all their speaker cables are about 8 feet in length.
Again just a thought.

Brauser,
In general I don't like subwoofers, but I did send an email to Bricasti to find out if I could connect a JL F112 subwoofer through my M1 DAC.

Theo,
I've tried several speaker cables(Transparent, Cardas, Shunyata)and thought the WireWorld Silver 7 was the most balanced.

Not familiar with your wires either, but as interconnects and cables can make a significant contribution to what level of tonal color is revealed I'd probably start there too. I'd demo a full loom Acoustic Zen as I know them to be very organic sounding without sacrificing things like detail and soundstaging that seem to be important to you. If that doesn't work I might try to audition a good preamp. Not sure how the Bricasti does as a pre, but some systems seem to benefit significantly by using a standalone preamplifier. If you're not tube averse maybe a VAC or ARC pre, and solid state maybe Pass Labs, Boulder, Vitus, Sim Audio. Hope this helps, and best of luck.

Richard, as I recall from one of your other threads not long ago you achieved a substantial improvement in bass performance via some revisions to how your bass traps are arranged. And you apparently achieved further improvement in bass performance by going to the M1 DAC.

My suggestion at this point is that you read through the lengthy ongoing thread Is DEQX A Game Changer?, and consider adding both a DEQX and one or preferably two subwoofers to your system.

As you'll see in that thread, several experienced members here have reported DEQX to be transformational in their already very high quality systems. They have reported it to be totally transparent apart from room and speaker corrections that are intentionally introduced, even when its internal A/D and D/A converters are in the signal path. (You would presumably use it entirely in the digital domain, aside from analog outputs it would provide to the sub or subs). Also see the review by Kal Rubinson (A'gon member Kr4) of one of the DEQX models, which recently appeared in Stereophile.

Also take a look at the DEQX site, including the section of their FAQ about subwoofer integration, which DEQX processing facilitates and optimizes.

Personally, I'm planning to purchase their latest flagship model HDP-5 as soon as its forthcoming production run arrives in the USA, which is expected to be in May.

Depending on your choice of DEQX model, subwoofer model, and the number of subs, the total cost of all of those things would come in either right around your stated budget, or for not a great deal more (although I recognize that under this approach you would not be selling anything to offset part of that cost). I'd be surprised if an amplifier change would accomplish anywhere near as much. And I'd be surprised if a $10K investment in new speakers would give you the bass improvement you seek without a significant risk being incurred of compromises to the qualities of your present speakers that you are happy with.

Good luck. Regards,
-- Al