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Revel Ultima Studio2 loudspeaker Room Measurements

Sidebar: Room Measurements

Given that Fred Kaplan felt that Kalman Rubinson "underrated" Revel's Ultima Studio2 loudspeaker in his original review and how much I had enjoyed my time with the larger Ultima Salon2, I thought it worthwhile to examine how the speaker performed in Fred's room.

Fig.1 Revel Ultima Studio2, spatially averaged, 1/6-octave response (red) and of Verity Sarastro II (blue), both in FK's listening room.

The red trace in fig.1 shows the spatially averaged response of the Studio2s in FK's room. I derive this graph by averaging 20 measurements…

Music in the Round #29

For years, I have espoused the use of the same speakers (except subwoofer) in all positions for multichannel music. To have no speaker in the system contributing a different voice to the choir seems as intuitive as having the room acoustics not color the sound. Of course, this still doesn't guarantee perfect timbral match—positioning and room acoustics usually impose some unique characteristics under all but the most perfect and symmetrical conditions. You can hear tonal imbalances even between the left and right speakers of most two-channel systems simply by switching pink noise between…

Music in the Round #29 Page 2

The DV-60's sound was the cleanest and least characterful I've yet had here for DVD, SACD, and DVD-Audio, but with a little effort, even it can be made to sound a bit bland. One of the salient features of the player is its ability to choose among upconverting filter configurations or to convert PCM to DSD. It is the latter that, in my opinion, goes a bit too far. Playing PCM-sourced discs using the default FIR filter, in either the Wide or Narrow setting, the DV-60 was as smooth, clean, and transparent as my reference universal player, the Bel Canto PL-1A, but with a marginally reserved…

Music in the Round #29 Recordings In The Round

Sidebar: Recordings In The Round

CONCERTGEBOUW BRASS ENSEMBLE: Brass
Music by Bourgeois, G. Gabrieli, Henze, Schmidt, van Otterloo, Woud
Ivan Mylermans, Concertgebouw Brass Ensemble
RCO Live 07002 (SACD).

This is simply glorious brass playing, and although most of the music was unfamiliar to me, it was all exciting and enjoyable. Except for Giovanni Gabrieli's familiar Canzon in echo duodecimi toni a 10, the works are from the late 20th century, but all are approachable and melodic. The Serenade by Willem van Otterloo (whom I knew, from my old Epic LPs, as the…

Listening #63

I'm old enough to remember my family's first table radio that was made out of plastic. It was cream-colored, and it sat on the rearmost edge of our kitchen table: a less-than-timeless design in its own right, destined to be discarded at the end of one era and treasured again at the dawn of another, for more or less the same reason. But in 1958, a cream-colored plastic radio looked fresh, clean, and right, and its cheap wooden predecessor seemed dowdy and sad by comparison. That would all change in later years, of course. Then it would all change again.

The plastic timeline…

Listening #63 Page 2

A smaller board, adjacent to the one containing all the pots, is the 3D's wafer-switch board. "That does three things," according to Morecroft: "It selects the input signal on the live side, to pass along to the volume control. Simultaneously, it does the same thing on the ground side. So if you've got, say, a DVD player connected to the preamp, you don't want its crappy or dubious ground to infect the performance of another source." The last wafer switch routes the signal through to the various source trimmers.

"If you could look at the circuit in three dimensions," Morecroft…

Classé Audio Fifteen power amplifier

I think every audio reviewer hopes for a surprise—when a good, but not outstanding, product is refined by the manufacturer into something special. The review then becomes an exciting discovery, reaffirming the pleasure one takes in good audio, and in listening to music being reproduced as it should be. It makes the listening exciting and the writing easier. The Classé Fifteen solid-state stereo amplifier is just such a surprise.

I first heard the Fifteen in an earlier version, the DR-15, when Classé's president Glen Grue shipped me an all-black pair of them while I was reviewing…

Classé Audio Fifteen power amplifier Specifications

Sidebar 1: Specification

Description: Solid-state stereo power amplifier. Rated output power (20Hz–20kHz): 175Wpc minimum continuous sinewave power into 8 ohms (22.4dBW), with no more than 0.1% THD (FTC); 375Wpc minimum continuous sinewave power into 4 ohms (22.7dBW), with no more than 0.3% THD (FTC); bridged-mono, 700W continuous sinewave power into 8 ohms (28.5dBW), 1200W mono into 4 ohms (27.8dBW). Frequency response: 20Hz–20kHz ±0.1dB. Input impedance: 70k ohms. Voltage gain: not specified. Power consumption: typically 225W at idle.
Dimensions: 17.25" (431.25mm) W by 7.25" (181.…

Classé Audio Fifteen power amplifier Associated Equipment

Sidebar 2: Associated Equipment

My listening room is 26' long by 13' wide, and has a 12' semi-cathedral ceiling. An 8' high by 4' wide doorway at the back of the room opens onto my 25' by 15' kitchen.

The Classé Fifteen amplifier was driven by a number of preamplifiers, including my favorite, the Classé Six Mk.II set to Bypass mode. I compared the Fifteen with my well-broken-in solid-state Mark Levinson No.27.5. I conducted additional gain-matched listening tests with a Krell KSA-250 and a pair of Woodside M50 monoblock tube amplifiers. I focused on low-frequency extension,…

Classé Audio Fifteen power amplifier Measurements

Sidebar 3: Measurements

A full set of measurements of the Classé Fifteen was made in its balanced mode; selected measurements were repeated for the unbalanced configuration. Unless otherwise noted, the results presented are for the balanced configuration.

Following the 1/3-power, one-hour preconditioning test, the Fifteen's heatsinks were hot, but not too hot to touch comfortably. The Fifteen's input impedance measured under 76k ohms, balanced and unbalanced. Its output impedance was under 0.017 ohms at either 1kHz or 20Hz, increasing to (or under) 0.045 ohms at 20kHz. Gain into…