I want profoundly better bass

Looks like I caught your attention. I have a moderate sized stereo room that is about 12.5 feet wide and has no rear wall for almost 32 feet. With a large opening for the stairs on on side of the front of the room I have a fairly large area in which to propogate bass. My current speakers are either a pair of Apogee Mini Grands or a pair of Meadowlark Audio Hot Rod Herons. I have VTL MB-450s, A forte 4 and Vtl Tiny Triodes (with Infinicaps) with which to play amplifier roulette. Preamp is a hot Rodded VTL TL. 2.5 and Digital Source is an Ayre Cx7e. Vinyl is via a Dynavector 20Xh strapped to a Rega P-25 that feeds A Plinius Jarrah.
Here is the $64.00 question. Given the 2 speaks I have now and their proclivity to warmth and subtle detail, what would somebody suggest I do for speakers with PROFOUNDLY better bass? Budget is somewhere in the 5K range used preferred. If your thoughts are to subs, no thanks as I have been down that road. Even the Minigrand's subs are a bit too much slop and giggle compared to the panel parts of the Apogees. Here is another hint. BIG sound is good as long as images are not too stretched. Re. I do not want a 10 foot tall Diana Krall in my living room. I already married a gal who looks like her (only better) and would be very afraid of a ten foot tall woman. Thanks in advance

Talon Khorus. They go down to 17hz and you can find them used for under $5000.
Legacy Focus 20/20, the dip low and have a beautiful finish. I am looking into VMPS hybrids also BUT vmps doesnt dip[ below 20 cycles
Excellent recommendation by Frankg. I tried out the Khorus and could not believe the value and performance over Thiels. Outstanding bass dynamics and great great resolution.
I'm guessing that profoundly better bass doesn't necessarily mean speakers that go lower. Have you done any measurements of your system in your room to identify what's going on? Room treatments or equlization (digital or analog) might ultimately be a more successful solution for you than chasing after a pair of speakers that complements your room.
seek out subwoofers from rel and velodyne
I'm listening to a pipe organ CD through older paradigms and my DIY subwoofer.This system images like a king and with the subs calibrated with TrueRta I think you should rethink subs.IMHO.
Meadowman, I'd like to address your statement about playing amplifier roulette only.

Simply because I think any good quality or better full-range speaker is capable of giving you the bass that you may be seeking.

The problem is that there only a few amps capable of reproducing such bass possessing such absolute controlling power over the woofer driver like you never thought possible.

For even finer tuning of the bass regions, I would not underestimate the significance of speaker placement, the interconnects, and speaker cables. Some to many ics and scs induce much time smear which simply translates to a bloated and/or ill-defined bass.

Oh, yeah, I almost forgot to mention the significance of proper vibration control and line conditioning.

All these are contributing factors toward successfully achieving the best possible bass that is not only profound but a deep, tight, well-defined, bass, that when called upon knocks you square in the sternum (but not across the room) and produces that PR&T that instinctively gets your toes tapping and head bobbing.

But none of the sonic benefits of these other ingredients, even when combined, will quite compare to the quality of acquiring the right amplifier to control the woofer drivers.

the new fried, gradient revolution
You MIGHT be able to find a used pair of Vandersteen 5A's in that price. With an active subwoofer built into the 3-way design, it produces serious bass notes. Overall it's a very good speaker.
I agree with Stehno. If you have your equipment sitting on their feet or on some damping material, try spiking them with brass spikes (I use AudioPoints, www.audiopoints.com), and definitely don't forget to spike your speakers.

The spikes tighten and focus the sound more than many people realize, and it's a fairly cheap place to start. I've recently gone from the individual spikes to AudioPoints complete stand, the Sistrum SP-6. I've even found that not using the brass disks with the spikes tightened things up even further.

There may be used spikes on Audiogon, because as people (like me) go to the Sistrum stands that come with their own spikes, they have the others sitting around. I have a bag of them myself.

Damping might work, but it's a double-edged sword, too much damping dulls things.
Some amps will provide iron-fisted control over the woofers - think Krell. Another possibility might be to go with speakers that have active built-in amplification. I would recommend Genesis (V, 500, 501), which are warm and have incredible but natural bass down to 20 Hz. Wilson speakers (5.1) have pop but not the deep bass you seem to crave. I am not a fan of the 5.1 as it is too dry/sterile (I realized this after I sold them). Maybe Eggleston Andras.
Sounds like you have a fair amount of cubic feet in that room.

At that price point, B&W Nautilus 801 or Vienna Acoustics Mahlers come to mind. Both produce prodigious bass that usually sounds boomy unless the speakers are driven by the right amps in big rooms. The B&W's are pretty impractical because they require bi-amping with serious solid-state amps, but can produce truly low bass (below 30 Hz.) and move a lot of air. The Mahlers have really potent midbass, are easier to drive and are 90 db. sensitive, but drop below 3 Ohms in the bass and require a top-notch solid-state amp to control the woofers. The Mahlers may be tough to place if you listen on the long wall, as they are rear-ported (the B&W's are bottom-ported).

In view of your amplifiers, these suggestions probably do not help much, but it's going to be tough to find a speaker that moves a lot of air with any finesse at that price point that does not require really potent solid-state amplification or that will work with typical tube amps. If you are patient and flexible with speaker placement, maybe a pair of subs would be a better way to go.
Von Schweikert Vr4 jr's may give you what you need. I had them in my room which is just as large and it almost did the trick. Big rooms need big speakers so I went to the 7's
I'm going to say it anyway... perhaps you can audition a Velodyne Digital Drive series sub with the room equalization sofware and have it professionally set up so as to obtain the best results. The software really does work and may just tame what you didn't like before. A DD-18 is in your budget and for 5 large someone has to through in the room service, I'd think.
If that is what is most important to you, then Talon Khorus speakers are it for you.

I think drubin gives wise advice on the issue. Also if Meadowman could give some qualifiers as to what he think 'profoundly better bass' should sound like then that would help others in their recommendations. Does better bass mean more bass response, smoothing out the peaks and dips in bass response, additional extension, enhanced pitch resolution, better driver control, etc.
Yeah, I'm with Drubin. Room treatments and speaker placement are the first things you should experiment with before laying out a bunch of cash. You've got a narrow and long room...narrow will give you big corner distortions (12.5' will give you a node at 42hz), and long (lots of cubic footage) will make it tough to keep sound pressure in the room.

Try some bass traps in the front corners, and some "triangle" absorbers for the upper front corners. Something in the intersection of the front wall and ceiling (right in the middle) will also help eliminate some slap echo and clean up low frequencies. Some companies with good products for these are: Echo Busters, Eighth Nerve, RealTraps, Acoustics First. The Eighth Nerve and RealTraps stuff is extremely affordable, and an excellent value for the improvements they will make in a room that currently has little treatment.

(disclaimer: I'm a dealer for Eighth Nerve and Acoustics First)

Not quite sure what you can do about the length of the room to keep sound pressure in except perhaps to "shorten" the room with some furniture or barriers to divide the room (bookcases, etc). What are your limitations in terms of aesthetics and functionality? It sounds like this room might be your living room?
I don't know that your prejudice against subwoofers is warranted.

In order to fill your huge room subwoofers might be the best option. Not all subs are created equal. Vandersteen subs and REL subs seem to be highly musical (i.e. fit for the most critical two channel audio listening). Positioning them at the back of the room may help "fill" the void. I would recommend a pair, since much low level info does come on either left or right channel.
My listening room is 13x23 and is filled quite easily by the bass created by twin pairs of Eminent Technology LFT-8A's as main speaker, along with pair of Vandersteen 2W subs. That's 10 8" drivers for bass. Even the lowest frequencies are reproduced without effort. I actually have the Vandy subs dialed down a bit since there's so much clean bass, they don't have to work hard at all.
I would caution using a sub with larger than 8" drivers in multiple configuration for use with panel/hybrid speakers, since it won't be able to keep up with the speed of the panels. But trust me, the Vandersteen sub can work fabulously with a panel speaker. I've used it with Magnepans and now with Eminents quite successfully.
>> But trust me, the Vandersteen sub can work fabulously with a panel speaker.<<
Amen. I'm using one Vandy 2W per channel in conjunction with a pair of Quad 988's and the sound is breathtaking. The three 8" drivers are superb with the Quads; very quick indeed. I have also adjusted the 2W "down" to match my room.
Two subs..one placed on each side of the mains, the acoustic centers of all in alignment for proper wavelaunch will ensure a wall to wall soundstage. Timbre matching becomes apparent when all speakers are mechanically grounded thru high speed devices so then you may perform coherent level match of all speakers. Settling time for all the speakers and their mechanical grounds will take several days.Tom
For 5k you can get the TacT 2.2X room corection preamp. This thing has been a revelation, and I have been reviewing gear for nearly ten years. I have heard a lot of stuff, the Tact has had one of the most profound impacts on the bass, and thus the rest of the spectrum. You may be shocked to see your frequencey response curve of your room. Mine looked like the Rocky mountains. The TacT not only corrects these anomallys, there is a parametric equalizer, as transparent as any preamp I have heard as well as the capacity to blend two subs into the system with a huge amount of control over the crossover points. Without this, I ewas shooting arrows in the dark hoping to hit on something. Give it some serious consideration, yo will not be disapointed. Greg
Coincident Tech. Total Eclipse
Legacy Audio Focus 20/20
Vienna Acoustics Mahlers
Talon Raven C???
Used Legacy Whispers or Verity Audio Parsifal Encores...

You will have what you are looking for with these. And no sub !
These are my own finalists. Actually the Totals and Focus 20/20
Vienna Mahlers work very well in large rooms, they disappear in the soundstage and have excellent bass extension and resolution. They prefer lots of space from the walls, and need an excellent amp to keep the bass under control. I have had good luck driving them with Pass X-350 and Bel Canto Evo4 Gen2 in my room. They are definitely warmish, not as transparent as your panels up top but the mids are very accurate and expressive. I tried the Von Schweikert VR4-jr's, not enough bass for a big room unless you leave the shot out, then it is muddy.
Raven C's with high current, high powered amps play extremely deep, tight, tuneful and fast bass. You will not even consider a subwoofer in a 2 channel system. Incredibly accurate and musical bass response when driven properly. MM
The big Velodyne servo Sub will probably do the trick for under $4000.
Stereophile gives it class-A for integrating with fast panels and electrostatics.

The problem with replacing good mains like yours in order to get better bass, is that you end up throwing out the baby with the bath.
ie: you might get the bass you're seeking, but then you'll end up sacrificing the midrange and treble you're apparently satisfied with.