ProAc Studio 100 loudspeaker

Of all the speakers I've heard through the years, the $3000 ProAc Response 2 (footnote 1) is definitely one of my all-time faves. One of the few high-end speakers at any price that sounds equally at home pumping out Prong as it does Puccini, the Response 2 blew me away with its incredible musicality and just plain "rightness." The Response 2 doesn't call strict attention to any one area of technical achievement, like so many Audiophile-Approved jobs, but just makes music so naturally and unforcedly that I hesitate, even considering its remarkable performance, to call it an "audiophile" loudspeaker. Yah, I dig the Response 2! So last year when ProAc introduced the Studio 100, a new affordable version of the Response 2, I got excited.

Laying out the long green to the hurtin' tune of $3k for a pair of small stand-mounted two-ways—however great they may be—is a real stretch for most people. Can ProAc make the same magic for just $1400?

Ostensibly an update of ProAc's older Studio 1 Mk.II, the new Studio 100 is a stand-mounted ported two-way. Identical in appearance to the Response 2, with its tweeter offset to one side, the Studio 100 differs from its pricier sibling in both parts and bass-loading. Its 6.5" paper-cone woofer and 1" fabric-dome tweeter are less-expensive versions of the hardcore Danish ScanSpeak drivers used in the Response 2. And while the Response 2 utilized Stewart Tyler's drinking-straw–filled port loading to split the diff between ported and sealed bass-loading by increasing the wind resistance in the port as them spls climb, the Studio 100 is a textbook example of straight port loading—no straws to be seen in the 2"-diameter port.

Much attention was paid to the Studio 100's cabinet construction. By using advanced damping materials and cabinet walls of nonuniform thickness, ProAc claims a much more inert construction. The crossover is internally "split" to allow for bi-wiring via two pairs of cool-man rhodium-plated Michell binding posts. Physically, the Studio 100 looks just like the Response 2, and is a hefty chunk of wood—the teak-finished pair I got looked mighty 'spensive indeed. ProAc recommends the use of heavy steel stands, like Target's HK20/2; for the porpoises of this review, I used both a pair of 24" Merrill sand'n'lead-fillable stands and the 30" Sumiko stands that were sent along with the Sonus Faber Minuettos.

I liked these speakers plenty. It definitely took some serious system-matching experimentation to get them singing, but once I got all the i's dotted and the t's crossed, the Studio 100s had the same kind of easily heard rightness to their sound as ProAc's more expensive models. At its best, the Studio 100 sounds like a junior-varsity Response 2, with a good dollop of the $3000 speaker's coherence and musicality at less than half the clams. The Studio 100's sound is quite a bit more compromised than that of the justly lauded Response 2, but the family resemblance—the "ProAc Sound"—was immediately noticeable.

Even so, it took a while to get what I felt was acceptable performance from the Studio 100s. While their break-in time seemed much shorter than that of most speakers I've had through here, merely heave-ho–ing the big NHTs out of my listening lair and plopping the ProAcs into my reference rig did not immediately result in happy happy sound sound. Dropped right into my usual rig, the speaker's balance was very forward and bright, with an over-sharpness that didn't suit extended crankage of Soundgarden's Superunknown CD (A&M 314-540 198-2), which I've found hard to remove from my transport lately.

Swapping the silver Kimber cables out for the copper PBJ and 4TC helped sweeten the sound a bit, and changing to the OCOS speaker cable smoothed the treble over even further, but the overall balance was still pretty forward and bright, which I found surprising from a speaker wearing the ProAc badge. Even driving the speakers with an Exposure IV Dual Regulated—an amp with a much softer high end than the Aragon's—didn't really smooth the Studio 100's sound out acceptably enough—although it did help.

The Studio 100s weren't way overly tizzy like so many purportedly high-end speakers, but they were just on the outside edge of acceptability—even for someone like me, who usually prefers a slightly forward balance to one that's duller than neutral. I wasn't really expecting the Studio 100 to equal the smoothness of the Response 2, but it fell short enough of that mark to get me wondering about what was wrong here. I'd had no such system-matching problems with the Response 2s, whose extremely EZ-2-drive load and "take all comers" character rewarded me with great sound whether the rest of the system featured tubes or solid-state. But it occurred to me that, in all the ProAc demos I've heard at CESes over the years, Modern Audio Consultants' Richard Gerberg has always used a tube amp; was it possible that these affordable Studio 100s needed a tube amp to sound their best—even though the He-Man ProAcs worked well with good solid-state? Even when I switched to the softer-sounding Exposure, the Studio 100s just squawked, "Tube us!"

So I did. At first, the only tube amp I had on hand was my trusty Dynaco Stereo 70—the classic–but–dated-sounding 30W amp from the 1950s I rebuilt with modern parts several years ago. I keep the Dyna around partly for sentimental reasons, but mostly because I like having an amp I bought used for $50 and put another $50 worth of parts into that sounds better than the cheap Adcoms/Rotels/B&Ks. It was also a lot of fun getting my hands dirty rebuilding the Dyna—which is more than I can say about flashing the plastic for a cheap'n' gritty solid-state amp and then trying to bullshit yourself into liking what you hear.

The Dyna is hardly the last word in tube sound—being more of a warm, snuggly, "vintage"-sounding amp than most modern tube designs—but its overly rolled-off high end was just the ticket for the Studio 100. With the treble-challenged Dyna in the driver's seat, the ProAcs' balance was far more neutral, and the HF spit was pretty much gone. Driven by the vintage Dyna, the ProAcs had a very detailed, natural midrange, with only a trace of the upper-midrange forwardness and edge heard with the solid-state amps. The Dyna/ProAc combo's bass was pretty flabby and loose, but a fluffernutter (footnote 2) low end is probably the Dyna's biggest weakness after its severe HF rolloff. The Dyna did wonders for helping the Studio 100s really sing, but I clearly needed a better tube amp to hear these ProAcs at their best.

Serendipity strikes
Seldom seen in public but widely feared in the international hi-fi trade for both his tremendous physical strength and his erratic taste in footwear, Joe Roberts had allowed me a rare visit to the Sound Practices offices several weeks earlier to hear SP's Reference System #1—a horn-loaded speaker system featuring Dr. Bruce Edgar's celebrated Edgarhorns and Joe's 2W single-ended triode amplifier, the 45. Serendipity had struck—the sound, with Joe's two-watter, was amazingly good—it shattered all my prior notions about horn systems and single-digit amplifiers. It was one of those systems you never want to shut off until the last Al Green record is played, twice. So when I found myself with the Studio 100s and a desire to hear them with a better tube amp than my old Dyna, I arranged to borrow the 45 amp to try with the ProAcs.

That did it. As much of an improvement as I felt the Dyna made to the ProAcs' balance as compared with the solid-state amps, the 45 amp took it even further. Now the ProAcs had a vivid, hear-through sound that rendered well-recorded voices, like Johnny Cash's on his killer new American Recordings CD (American 45520-2), in a rounded, believable manner. This mostly mono CD is a great test of both a system's neutrality through the midrange and its ability to float a tightly focused phantom center image; the triode-driven Studio 100s passed both tests well. I was also very surprised at the more-than-acceptable levels the 2W amp was able to coax out of the ProAcs—no, it wasn't the kind of Stupid-Approved level I like to listen to rock at, but it was plenty loud enough to just almost do justice to Black Sabbath's Greatest Hits. Seriously! It was pretty cool. Your thought model tells you that two watts just can't be enough to drive a non-horn speaker to decent levels, but alls I can say is, try it.

Bass-wise, the 2W single-ended amp couldn't really drive or control the Studio 100s with as much authority as the Aragon and Exposure amps, which sounded better in the low end with the ProAcs. Even so, I felt the Studio 100's performance in the bass was fair rather than good—even with the iron-fisted Aragon, the ProAc's low end was a bit on the woolly side, with less tightness and control than I remember the Response 2 having, or the similarly priced Sonus Faber Minuetto. Bass lines were all there except for the lowest octaves, and the ProAcs could play impressively loud before the onset of audible distortion; but the tightness I've grown accustomed to with the mighty NHT 3.3s just wasn't there to the same degree with the Studio 100s.

I got the most focused imaging and soundstaging with the Studio 100s aimed right at me, toed-in from the sidewalls. Unlike the NHT 3.3s, the stand-mounted ProAcs sound best when they're positioned well away from the front and sidewalls; this gave me a very detailed, coherent soundstage that reminded me very much of the Response 2s', because the soundscape held up even if I moved my head all around or moved over to the couch. This kind of listening freedom tends to make for an extremely liveable speaker, and the Studio 100 shares this quality with the more expensive ProAcs.

While there was lots to like about the ProAc Studio 100, I have to reiterate that I only really liked what I heard when the speaker was driven by Gordon Rankin's 2W single-ended triode tube amplifier. Once mated with it, the ProAc sang like a bird—especially in the midrange.

That said, if you don't plan on chucking your solid-state amp, however good, for a tiny single-ended triode tube amp, I think your $1400 would be better spent elsewhere. Off the top of my head I can name the $1295/pair Epos ES 14, the $1000/pair Dunlavy SC-1, and the $880 NHT SuperZero/SW2P sub-sat rig as speakers that offer better sound overall. These are also much more suitable for use with a wide range of amplifiers, tube and solid-state. The Studio 100 has its virtues: an open, clean midrange, excellent image focus, and freedom from the "head-in-a-vise" effect common to those speakers whose timbres change dramatically with small movements of the listener's head. But, given the level of its competition, it also has faults that are hard to ignore: an overly forward balance through the mids, a ported woofer that sounds more "classic" than the tighter examples of the genre, and a tweeter that could use a few dBs knocked out from under its legs. The use of a treble-challenged tube amp is mandatory to hear the Studio 100s at their best.

While it didn't sound nearly as musical when driven by solid-state amps, the Studio 100's ultra-EZ load and highish sensitivity make it a fine alternative for single-digit triode fans who just can't see their way to using horns. Recommended, but make sure your amp glows in the dark.

Footnote 1: See my review in the July 1992 Stereophile (Vol.15 No.7, p.109).

Footnote 2: For those poor souls who didn't grow up in Suburbia, USA, a fluffernutter samwich consists of equal parts Kraft Marshmallow Creme and Skippy peanut butter on Wonder Bread—praised be thy chewiness. When the warden wants to know what you want to eat before they fry you, you tell 'em, "Make mine a fluffernutter!"

US distributor: Modern Audio Consultants
112 Swanhill Ct.
Baltimore, MD 21208
(410) 486-5975

remlab's picture

Oh yeah, now I remember, He's the guy that got run out of town by "Old goats". Heh heh.

Glotz's picture

He did push the limit on a few reviews... I can still picture Arnie Nudell's sneer on his face when Corey asked him to play some rock... sheesh- the hate was palpable.