Have been serious (at least tried) about audio for over 30 years. I've had really big three way speakers, the original Hafler pre/power amps, $300/pair two way standmounts, NAD receiver, McIntosh, etc. Epiphanies over the years include the dynamic/full bass from active speakers, single driver coherency, the deep/musical/uncolored sound of transmission lines, and keeping life simple. Stuff that hasn't done it for me include vinyl (can't stand the surface noise), tubes (flabby bass and sound that changes throughout the life of the tubes), and open baffle speakers (smeared wall of sound).
About 4 years ago we built a house that included a basement (concrete slab grade) man cave that primarily is my listening room. The 8 foot x 13 foot x 22 foot dimensions and nearfield layout follows Cardas recommendations. For almost no additional cost it is well isolated physically and electrically. Six GIK 244 high density fiberglass panels at front corners, front wall first reflection points, and side wall first reflection points complete the room.
Associated equipment -
Bob Brines FTA-2000 speakers (I commissioned this original pair)
Channel Island VMB-1 chip based monoblocks amps (40 watts/8 ohm)
Oppo DV-170HD universal player (used as a transport)
Scott Endler stepped attenuators (12 step, 4 dB model)
Element Cables Red Storm power cords (for the monoblocks)
Scott Endler digital cable/interconnects/speaker cables
Ikea "Eina" nightstand equipment rack (without wheels)
Super Soundproofing Co 2 inch square cork/neoprene isolation blocks
2x4 blocks and Styrofoam cups to keep cables off the floor
Music used - (yes many of those audiophile recordings)
Large classical compositions
Chamber music, especially baroque
Old school, modern, light jazz
Pop music from the 50s and since, Led Zeppelin, Dire Straits
Various crossover stuff like Bella Fleck's "Flight of the Cosmic Hippo", etc.
The FTA-2000 speakers use the "mighty" Fostex F200A driver (8 inch, AlNiCo, 91 db/w/m, 30 - 20,000 Hz, 8 ohms) in well braced floorstanding mass loaded transmission line cabinets ala Martin King. Like many other single driver designs, Bob includes a baffle step/zobel circuit.
Part of being an audiophile is never being quite satisfied. So being a "speaker guy" and a "room guy" a Scott Endler modified Behringer DEQ2496 was added to the mix. As many know, the DEQ2496 can serve several functions including digital equalization and digital to analog conversion. Scott's mods relate only to the DAC. Although the Oppo was Stereophile Class C rated I felt that it was a weak link in the system. I played with the DAC without EQ briefly. Detail, imaging, and frequency extension all were improved. I've discovered brushes on cymbals that are playing along with snare drums. After 100+ hours overall focus of each instrument continues to improve, highs are still smoothing out, and the level of resolution increases. Overall the sound seems leaner, more "to the point". Bass is less mushy, more solid. The work (mods, cabling, and attenuators) took a couple of months, but was flawless. Scott kept me in the loop the whole way.
Then I got into the EQ by replacing the baffle step/zobel and added Scott's speaker cable. (With the DEQ2496's XLR jacks I'd never been able to use the unit.) This removed non-audiophile grade cap/resistor/inductors in the baffle step/zobel and overall reduced the number of connections to pretty much an absolute minimum in the system.
It took some playing with (and I'm sure that I'll play some more) but, wow! First, you won't believe the masking/smearing that occurs when the frequency response isn't really flat. Everything sounds clearer, resolution is further enhanced. Secondly and more to the point (finally) you can extend the usable frequency range. Without any (nasty) whizzer cones, the F200A drivers beam high frequencies like crazy even though they're rated out to 20,000 Hz, but adding some boost helps balance out the beaming.
The big news though is the increased bass response. During a previous single driver audiofest the FTA-2000 left most slack jawed (in a 6,000 cu. ft. room with 2 - 25 watt amps and without the baffle step/zobel circuit!). But now, in my 2,000 cu. ft. room, and with EQ available the bass is amazing. Not boomy at all, but much more volume and deeper bass response than my HSU VTF-2 sub in a smaller A/V room can provide. The bass goes deeper/stronger and less warm/muddy (not that it was bad before by any means, just one of things you realize after finding something better).
Thanks to Warner here at AC (for selling me the used Behringer DEQ 2496 in the first place) and Scott for the mods, cabling, and attenuators. By the way, the 4 dB steps in his standard attenuators work great and are plenty flexible. With all the interest in music servers and computer based EQ, I suppose many see this as an old fashioned approach. I had tried a modded Squeezebox, but had continual technical problems that would take days/weeks for me to stumble into a solution for. Plus I didn't like having to power up the computer to listen or ripping every disk I listened to. I do keep looking at servers, hoping to find something that has good sound, is idiot proof, and not too expensive.
Scott's website explains his offerings and modding approach: http://mysite.verizon.net/vze4c5pt/