Monitor Audio Studio 6 loudspeaker
By John Atkinson   •   March, 1994 Back in the summer of 1968, I bought a secondhand pre-CBS Fender Precision Bass guitar for the grand sum of £35 (then about $75) (footnote 1). It was so cheap because the previous owner had pretty much scratched the sunburst finish to ribbons. The P-Bass may have looked like roadkill but it played like a dream, so I decided to refinish its body. Paint stripper removed the remains of the original nitrocelloluse lacquer, leaving me with a white wood body—ash, I understand—which I carefully sanded and stained. Contrary to what you might expect, the finish of an electric guitar does have an effect on the sound, so I thought long and hard about how I was going to varnish the body. I ended up applying thinned gloss-finish polyurethane, which I then sanded, repeating this process some five or six times, using finer and finer sandpaper, until the application of a final coat of varnish gave as close to a mirror-smooth finish as I could get...which wasn't anything near as perfect as the piano-lacquer rosewood finish on the samples of the Monitor Audio Studio 6 loudspeaker that Monitor Audio USA sent for review!

The Studio 6...
...is the fourth model in the English manufacturer's Studio range to be reviewed in Stereophile (footnote 2). All the Studio speakers are two-way designs featuring all metal-diaphragm drive-units. ("Metal" is actually a misnomer: the diaphragms are heavily anodized, this adding a strong ceramic coating which significantly stiffens the material. When I taught science, one of my favorite experiments was to get my students to anodize an aluminum rod, then melt it in the flame of a Bunsen burner. Much to their surprise, the molten metal would hang safely in a bag of the anodized oxide coating, which is a very hard, strong material related to sapphire.)

The 6's tweeter is made by Monitor Audio and features a gold-anodized aluminum-alloy dome with a tiny nitrile-rubber roll surround. Ferrofluid is used to cool the unit's voice-coil, which is wound on a vented aluminum former. There is no protective cover over the tweeter, so those with inquisitive two-year-olds should make sure they keep the grilles on.

The woofer, again made by Monitor Audio, is built on a diecast chassis and has an anodized aluminum cone with a shallow flare, 5" in diameter, terminated in an inverted roll surround, this again made from nitrile-rubber. A shallow aluminum dustcap covers the end of the voice-coil former which is made from aluminum and insulated from the coil by a layer of Nomex. The high degree of metal used is said to increase power handling and reduce thermal compression by providing more heatsink area than is usual. The woofer is reflex-tuned by two 1"-diameter, 4"-deep ports on the front baffle below the tweeter. These ports have flared exits to minimize wind noise.

The crossover is said to be minimal. Electrical connection is via two pairs of gold-plated Michell terminal posts on a recessed rear panel. Bi-wiring is recommended. The cabinet is fabricated from 18mm MDF and is heavily braced and damped. Both drive-units are rabbeted into the baffle and the finish is either a high-quality wood veneer or, for an extra $700/pair, a high-gloss piano lacquer. According to Monitor's Mo Iqbal, when I asked him at the 1993 WCES how many coats of lacquer there were, "The cabinet finisher is asked to keep going until the speaker is perfect!"

Break-in
Kevro's Robert Sinclair had advised that I "burn-in" the speakers for "a good two weeks" before I did any critical listening or measuring, due to the drive-units and some crossover components changing during the initial period. Certainly, there was a very bright edge to the sound of the speakers straight from the box that intruded on the music. Accordingly, therefore, I placed the speakers face-to-face, wired them out-of-phase, and drove them with high-level pink noise for about 48 hours (footnote 3). After the break-in period, the mid-treble peakiness was significantly less disturbing. The drive-unit fixing bolts all seemed a little loose, however, so this is probably something that Studio 6 owners should check regularly.

Sound
Prior to the Monitor Audios taking up residence in my room, I had been listening to the NHT SuperZeros that Corey Greenberg reviewed in January (Vol.17 No.1, p.139). The $199/pair NHT is indeed an excellent loudspeaker for the money, offering as much musical satisfaction as a speaker costing significantly more. But when I first listened to the Studio 6es, I breathed a sigh of satisfaction: the English speakers offered such a cleaner, more transparent view into the soundstage, such a considerably more refined presentation of the music, that I was reminded of the very first time, following a steady diet of budget speakers, that I heard the Rogers LS3/5a, back in 1977. Subtle where the lesser speaker was brash, deeply detailed rather than all up-front, the Studio 6 was obviously a high-end speaker from the moment I fired it up.

Its overall balance was on the forward side, the midrange being pushed a little at me. I could also hear this effect as a trace of nasality on pink noise, this signal also revealing that the speaker's top octave was a little suppressed. Though it made solo violin sound somewhat muted, this rather mellow treble was not musically intrusive, perhaps due to the speaker's excellent clarity and sense of transparency. I got the feeling that every little bit of recorded detail was audible, though not in the spotlit manner of some "audiophile" speakers. The different textures of the background noise on each track of the second Stereophile Test CD, for example, were easily audible.

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Footnote 1: The Fender, serial number L16706, served me well during my professional musician career, and it still sits, ready for action, on a stand next to my listening chair. (It sounds better than any air guitar I've tried.) It can be heard identifying the channels on Stereophile's Test CD 2, as well as on the two Mondial-sponsored CES jam-session CDs released by Bainbridge, yours for a $30 contribution to the LA chapter of MADD. For availability, contact Bainbridge Records, P.O. Box 8248, Van Nuys, CA 91409-8248. Tel: (213) 476-0631. Fax: (213) 472-4190. Those interested in reading more about Leo Fender's seminal invention should check out The Fender Bass, by Klaus Blasquiz, Hal Leonard Publishing, 1990.—John Atkinson

Footnote 2: I reviewed the now-discontinued Studio 10 and Studio 15 in Vol.13 No.11 and Vol.15 No.6, respectively, while Robert Harley's report on the still-available Studio 20 appeared in Vol.14 No.12. Sam Tellig also wrote about the Studio 20 in Vol.15 No.4.—John Atkinson

Footnote 3: There is current discussion of whether pink noise—which contains equal amounts of energy per octave—is the best signal for break-in. A CD-R available from Purist Audio Design (for $150!) contains 63 minutes of computer-generated noise signal said to be optimal for system break-in.—John Atkinson