A pair of used Snell Model Cs, one thru three versions. Vandersteen 2Ce, 2Ci, Nht 2.5i....these are all examples of relatively modern speakers that would give you a nice warm, full bass on a budget....about $300.00 to $700.00 a pair. The later Snells with the poly woofers might not be so warm, but real punchy and fast, and very good none-the-less. Oh there are others to be sure, like the Snell type A, first iteration, absolutely wounder-full, big and warm, but the ones I mentioned above are the ones I am presently playing around with....again.
But why not go back to the beginning, the very beginning....well almost. A good pair of early AR3As, using the woofer that was first use in the Ar3s, set up on 24" high stands, or in my case on 24" high old Warfdale cabinets, will give you a bass that defines what warm bass is; yet it will still be very detailed at the lowest end, with lots of upper bass thud and fullness when you want it...plenty fast too.
Acoustic Research (AR) invented big bass in the small (by standards of the day, 1950s/60s) package, and I don't care what anyone says, the AR3....granddaddy to all 3way acoustic suspensions designs, and the first speaker ever to use dome drivers, invented by AR....and the AR3a are the most satisfying speaker systems I have ever heard; I've owned hundreds...wilsons/watts/puppies/maggies/acoustat/psb/paradigm/nht/duntek/and on and on/advents/bose 901/canton/b&w/ess/ohm/klipsch/eminent technology/etc.,etc...you name some for me, and I'll tell you yes or no as to weather or not I have owned them because my memory for names fails me at present. But no matter how many times I've strayed, and no matter how many speakers systems I've put up at any given time, I always find myself coming back to the ARs....
The others are usually more efficient, so they seem to have an advantage, but come back I do; with my current amps, McIntosh MC252, transistors, and Masa Baron, tubes, the efficiency advantage seems moot since I have plenty of power to play the ARs satisfyingly in my 15' x 25' x 9' listening area. The big (called bookshelf in their day) ARs have remained with me for decades, while others have come and gone. They have pretty good extension in the highs, nice defined midrange, and a bass that is big, warm, but also tight, fast and defined....the ringed woofers are a work of art, and kill anything found on modern speakers costing upwards to $5000.00. The solid, all wood through and through cabinets hark back to the days when building a fine speaker was really a craft. Spend 3 grand on a pair of speakers today, and you still don't get real wood through and through, not in most cases. The big ARs are something to cherish.
The 3As might be better than the 3s for those who crave a bit more highs....or slightly modify the crossover of either, and add a more modern tweeter if you like; be sure to perfectly seal the cabinet, and make sure you have the correct amount of fiberglass baffling material installed. This makes a big difference in the bass capabilities of the speaker.
One last thing about the ARs....these speakers do not sound boxy at all, like some ported designs do. Even ones costing several thousand dollars. And they image very well, with a very detailed center stage; even staging to the outside of the speakers, that is if the recording is done that way, they will present it, with all the positioning of the vocals and instrumentation, etc., rendered spaciously intact....I love them!
Yet, invent the same thing anew they do...."On our waste to perfection," each generation, until all the generations are born and have lived and died, seeks to find that which is important, or of real value. So, go go go....a new gimmick a day keeps the blues doctor away, but there's very little in audio that's truly new under the sun....except your new speakers, yeah!! "On our waste to perfection, we have reached a new direction"......yeah,,,yeah.
