Upgrade from Merlin VSM-M to What?

I have a wonderfull pair of Merlin VSM-M speakers, but I want fuller range. I have the balanced/single ended battery bam and it does extend the bass, but not as low as some other full range speakers. I have been lead to believe that my Karan KA-i180 integrated amp could sound even better with fuller range speakers. I don't want to spend a bundle of money. I just purchased a Pioneer 5060HD plasma and my budget for speakers are $1000.00 more then I will get for my VSM-M's. So my hope is for used speakers costing between $4,000.00 - $4,500.00. My thoughts are toward Dunlavy or Eggleston. Shipping these speakers must be taken into account. I do have sub woofers, but don't use them. They are Velodyne servo 1200's. My integrated does not have preamp outs and I think using the subs x-overs in the speaker line would harm the sound.
Suggest you Keep the already excellent Merlins and get TWO better subs. Perhaps the Vandersteen 2wq model.
All it seems you are wanting is the low end that the Merlins are not providing. However they are about as good as it gets the part of the audio spectrum that they do cover.
Good luck!
Why not upgrade to the MX with the super-BAM? It is true that the bass will not go any lower, the cutoff/filter/whatever is still at the same frequency, but the MX with the Super-BAM produces much more, and much better bass, than the old Milleniums with the old BAM. If you listen to pipe organ music or electronica or anything with 20 cycle bass, then going to the MX won't work, but otherwise it will be an improvement. In my room, with my system, it almost sounds like there IS a well-integrated sub in the system. Bass weight, clarity, and articulation improved dramatically with the MX ( i had the Milleniums too before going to the MX) and even more so with the super-BAM.
Again, though, if what you're looking for is LOWER bass than 28 cycles, you'd have to go elsewhere.
How is it possible to integrate a sub into a system using the merlin bam and having no preamp outputs in my integrated? I don't need 28 cycles, just more of what the VSM's do. I am afraid to ask what the upgrade cost is to the MX and Super-BAM + shipping. My budget is $1000.00. I am surprised at the used asking price of VSM-M speakers. I purchased mine used. At $7200.00 new and asking less then $2500.00 used seemes cheep. Other speakers that are older and cost about the same new are asking, and I assume getting $3500.00 and up. Why?
I recently bought a used pair of VSM-MXs, and upgraded the BBAM myself to work with large external SLA batteries. This upgrade (or doing the Superbam upgrade for $450 thru the factory) will increase the performance of the VSMs by an astonishing 30-50%. They will have more bass authority, bigger dynamic envelop, tactile realism, and greatly reduced midrange and treble grain. I have not heard speakers at any price surpass the Merlins in refinement after these mods. If after upgrading the BAM you need deeper bass, then sell your amp and get a preamp with a line-level output to a sub.

Also, have you properly set them up? The bass extension of the VSM is finicky-- very dependent upon placement and correct use of the spikes/cones.

Don't sell them!!