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A dream I have had since I discovered the pleasures of music is to possess a time machine. Not a fancy one, just a small device that would allow me to escape modern music-making and drop in to hear what must have been some of the greatest musical experiences of all time. Classical music presents no problems: Off to 18th-century Leipzig on Sunday, of course, to hear J.S. Bach play the organ in church, after an early 19th-century Saturday evening spent in Vienna listening to Beethoven improvising at the pianoforte. During the week it would still be Vienna, but forward 80 years or so to hear…
The Gem is a graceful, narrow-aspect-ratio stand-mounted design, with twin mid/woofers vertically flanking a central 28mm tweeter (a high-performance soft-dome design from Danish manufacturer ScanSpeak). The 5.25" low-frequency drive-units are from Revel and use a one-piece titanium concave dome with a fluoroelastomer rubber surround, neodymium magnets, and a 2" edge-wound voice-coil with a Faraday ring to reduce magnetic distortion. The woofers are reflex-loaded with a 2"-diameter flared port some 6" deep; this vents on the rear panel. As with most of Kevin's Snell designs, a second tweeter…
No matter how I set the controls, there was always a slight mid-treble accentuation audible. Nothing to get bothered by, but it should be mentioned, and in this the Revel was not dissimilar to the B&W Silver Signature. Whereas the British speaker has a rather polite, laid-back balance with a voluptuous midbass, the Revel Gem sounds more neutral, both in its treble voicing and in the character of its bass. As Tom Norton noted in the July/August '98 issue of Stereophile Guide to Home Theater, the Gem is voiced a little lean overall rather than rich, which does make it a little more fussy…
One area of weakness for all subwoofers is the quality of the feed to the main, high-pass-filtered speakers. It's nice to have the bass extension, but not if this is at the expense of added midrange grain or a reduction in the soundstage. The LE-1 added a very faint treble haziness to the system's presentation that was noticeable on direct comparison but was not significant when I was assessing the system on its own sonic merits.
As I was writing up the measurements for this review, I was listening to the Adagietto from the 1991 Welsh Symphony Orchestra's live recording of Mahler's…
Specifications
Revel Ultima Gem: Two-way, stand-mounted loudspeaker with rear-facing reflex port and second tweeter. Drive-units: 1.1" fabric-dome tweeter, 0.75" rear tweeter, two 5" metal-cone bass/midrange drivers. Measured crossover frequency: 2.3kHz. Frequency response: 70Hz-15kHz, ±1dB of target curve; -10dB at 39Hz (2-pi anechoic measurement). Nominal impedance: 6 ohms, 4 ohms minimum. Sensitivity: 87dB/W/m. Power handling: not specified.
Dimensions: 19.5" (496mm) H by 8.375" (213mm) W by 17.375" (442mm) D. Weight: 40 lbs (18.2 kg) each with wood side panels; 48 lbs (21.8 kg)…
Revel Ultima Gem: Two-way, stand-mounted loudspeaker with rear-facing reflex port and second tweeter. Drive-units: 1.1" fabric-dome tweeter, 0.75" rear tweeter, two 5" metal-cone bass/midrange drivers. Measured crossover frequency: 2.3kHz. Frequency response: 70Hz-15kHz, ±1dB of target curve; -10dB at 39Hz (2-pi anechoic measurement). Nominal impedance: 6 ohms, 4 ohms minimum. Sensitivity: 87dB/W/m. Power handling: not specified.
Dimensions: 19.5" (496mm) H by 8.375" (213mm) W by 17.375" (442mm) D. Weight: 40 lbs (18.2 kg) each with wood side panels; 48 lbs (21.8 kg)…
Associated Equipment
Digital sources: Mark Levinson No.31.5 CD transport and No.30.5 DAC connected with Illuminations Orchid AES/EBU link; Wadia No.270 CD transport and No.27i DAC connected with ST-glass links; Nagra-D open-reel digital recorder, Tascam DA-38 MDM recorder, and Panasonic SV-3700 DAT recorder, all connected via a Meridian 518 reclocking unit (and a Prism MR-2024T bit splitter for the Tascam) and Canare 110-ohm AES/EBU cables.
Analog source: Linn Arkiv/Ekos/Sondek LP12/Lingo on Archidee table.
Preamplifiers: Mark Levinson No.380S with Levinson source components,…
Digital sources: Mark Levinson No.31.5 CD transport and No.30.5 DAC connected with Illuminations Orchid AES/EBU link; Wadia No.270 CD transport and No.27i DAC connected with ST-glass links; Nagra-D open-reel digital recorder, Tascam DA-38 MDM recorder, and Panasonic SV-3700 DAT recorder, all connected via a Meridian 518 reclocking unit (and a Prism MR-2024T bit splitter for the Tascam) and Canare 110-ohm AES/EBU cables.
Analog source: Linn Arkiv/Ekos/Sondek LP12/Lingo on Archidee table.
Preamplifiers: Mark Levinson No.380S with Levinson source components,…
Measurements
Other than impedance, all acoustic measurements were made with the DRA Labs MLSSA system and a calibrated B&K 4006 microphone (footnote 1). The Gem's voltage sensitivity (measured using a noise signal and a B-weighting filter to discount the effects of peaks and dips at the frequency extremes) was around 87.5dB/2.83V/m, which is fractionally if inconsequentially higher than specified.
Other than impedance, all acoustic measurements were made with the DRA Labs MLSSA system and a calibrated B&K 4006 microphone (footnote 1). The Gem's voltage sensitivity (measured using a noise signal and a B-weighting filter to discount the effects of peaks and dips at the frequency extremes) was around 87.5dB/2.83V/m, which is fractionally if inconsequentially higher than specified.
Figs.1 and 2 show the Gem's impedance with its controls set to give the most demanding amplifier loading (fig.1, front tweeter "+1" and rear tweeter "+4") and its kindest load (fig.2,…
Fig.3, a waterfall plot calculated from the output of a simple PVDF plastic-tape accelerometer attached to the center of the cabinet sidewall, shows that there is in fact one resonant mode present, and at quite a high level. However, the presence of extensive and well-positioned bracing pushes this up to a very high frequency, 670Hz, which will mean that it will both "fall between the notes" in the musical spectrum and, once excited, not ring for very long. And it should be noted that this measurement was made without the Gem bolted to its stand. When the speaker was attached to the stand, I…
The tweeter comes in a little higher in frequency than I would have expected. The ripples in its on-axis response are due, I assume, to reflections from the trim plates, which offer symmetrical obstructions in the tweeter's acoustic environment. These will be most severe exactly on-axis, but will tend to even out to the speaker's sides—as can be seen in fig.6, which shows the Gem's response averaged across a 30-degree horizontal window on the tweeter axis. Other than a slight lack of energy in the presence region, this is a very flat-measuring speaker! The tweeter control was again set flat…
Vertically (fig.10), the spaced woofers result in comb-filtering at extreme off-axis angles. The listener needs to listen to the Gem with his or her head between the centers of the woofers to get the designed balance from the Gem, hence the tall stands.
Fig.10 Revel Ultima Gem, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 45 degrees-5 degrees above HF axis; reference response; differences in response 5 degrees-45 degrees below HF axis.
Fig.11 shows the spatially averaged response (footnote 2) of the Gems…