ProAc Response 4 loudspeaker
But my system must not only satisfy me personally, it must also act as an evaluation tool for the gear I review. For example, as an audiophile I would never feel the need to own the wonderful Audio Research Classic 150 amplifiers—rarely have I needed that much power, and I typically wouldn't spend $5495 on a single amplifier. But as a reviewer, the Classic 150s have been ideal: they have protective turn-on circuitry and dual-speed fans which extend tube life, so the amps virtually can be used continuously; their power and output options make them compatible with almost anyone's speakers; their attenuators allow me to leave the amps on while I change cables; and speaker and cable manufacturers have been consistently satisfied when I've reviewed their products with the amp. Essentially, the Classic 150 has satisfied both my reviewing and personal needs.
As a reviewer and an audiophile I've long desired a sonically splendid, truly full-range loudspeaker with high sensitivity and an easy impedance load. The sonic splendor and full-range capability would satisfy me personally; the high sensitivity and benign impedance would allow me to review virtually any amplifier, including low-powered ones; and its full frequency range would make it an appropriate tool for reviewing other components.
Over the last five years or so, I've "compromised" by using the ProAc Response 2, 3, or 3 Signature as my reference loudspeakers. Although each is sonically stunning, high in sensitivity, and an easy load to drive, none has great extension into the deep bass. Nevertheless, these speakers have matched up extremely well to my personal biases and suited my audio reviewer needs reasonably well.
I lobbied ProAc designer Stuart Tyler tirelessly during this period to take a crack at a truly full-range speaker which would preserve the strengths of the Response lineup. My wish came true in mid-1993, when ProAc announced the release of the monstrous Response 4. I eagerly arranged to get a review pair. They arrived just before the 1993 Summer CES, and with the help of my two nephews, Ryan and Shawn, I lugged the two 355-lb boxes (which didn't include any sand or lead) into my basement and headed off to Chicago.
I got to the Show early enough to watch Richard Gerberg, the US ProAc distributor, unpack a pair of 4s. The packing is brilliantly clever: The +300-lb. boxes were placed down on the integral pallets, binding straps were cut, and the entire package was lifted off the speaker. The remaining pallet/speaker was tilted upright, and the speakers were slipped out into a standing position. The rest of the setup took muscle but was rather straightforward: the plastic covers were removed, the plinths were bolted on, the 4s were placed properly in the room, and four spikes (footnote 1) were inserted into each speaker.
I couldn't wait to hear the speakers. I was particularly impressed with the fact that their weight was due entirely to the heavy ATC drivers and the well-constructed cabinets.
Unfortunately, the Response 4 failed to live up to my expectations. My disappointment was shared by Bob Deutsch, who described what he heard in his Show report (Vol.16 No.8, p.93). All I could think of was unpacking, auditioning, repacking, and sending back over 700 lbs of audio disappointment. What could I do?
Rationalize! There had to be a reason for the ProAc's disappointing sound at the Show. After all, the CES set up featured all new wire with which I wasn't familiar, a brand new digital front-end I hadn't heard, new amps that weren't broken in, and a room that didn't appear to be a great match for the speakers. But each time I came back to ProAc's room, the overall sound was better. They played more analog, changed the wires, repositioned the room treatments, and the electronics were breaking in. Things got better, yes, but they never got good enough to justify the $18,000 price tag. It looked like the big ProAcs weren't going to be the answer to my dreams after all.
When I got home from Chicago, I replaced the Response 3 Signatures in my system with the 4s. The rest of the system consisted of the Koetsu Pro IV mounted on a Versa Dynamics 1.2, Mark Levinson Nos.30 & 31, CAT SL-1 Signature, ARC Classic 150s, dual Tice Power Blocks/Titans, and all NBS Signature cables. I aimed the speakers directly at my listening position—approximately a third of the way into the listening room and just under 3' in from each side wall.
The tide turns...
Much to my surprise, the 4s sounded very good right out of the box, much better than they'd sounded at CES. The soundstage was slightly narrow, with a tendency to be located well within the speaker-cabinet positions; there was a bit less top-end extension than I would've preferred; and the bass level, while extended, was somewhat uneven. Nevertheless, everything was naturally musical, harmonically rich, and immediately satisfying. I realized I could do a meaningful review after all.
The room placement of the 4s turned out to be much more critical than it has been with many other speakers I've had in my listening room. Since the 4s extended so low in the bass, room reinforcements and cancellations became problematic. I ended up moving the speakers in and out of the room, closer to and farther away from the side walls, and toed them in more or less. The best location turned out to be a slightly asymmetrical one: I placed the right speaker slightly farther from the side wall than the left, which meant that my listening position was no longer centered. Although the 4's initially uneven bass performance bothered me, once the best location was found, the bass extended powerfully to 50Hz and audibly down to 20Hz. In my room, I ended up with a mild peak at around 125Hz, but the bass overall ultimately became extended and relatively flat. The remaining bass unevenness may have been a room problem.
With proper placement, the 4s provided the power and authority missing in many speakers. This powerful foundation added a satisfying underpinning to music as diverse as the otherworldly soundspace of Brian Eno's "JuJu Space Jazz" on Nerve Net (Opal/Warner Bros. 45033-2) and the naturally recorded splendor of Stravinsky's Petrushka with Ansermet and L'Orchestre de la Suisse Romande (Athena ALSS 10004). Of course, this foundation was essential for the reproduction of most rock, especially metal and grunge.
Footnote 1: The spikes, terminals, and various other key components of the 4s are plated with the precious metal rhodium, which is resistant to tarnishing.—Jack English