Revel Ultima2 Studio2 Surround Speaker System Measurements
For logistics reasons, the samples measured were different than the ones auditioned. All measurements shown here were taken with the grilles removed.
The impedance of the Studio2 dropped to a minimum of 4.4Ω at 330Hz. The impedance magnitude in the bass is more linear than we usually see, making it difficult to determine the cabinet tuning from that measurement, but judging from the maximum port output it appears to be around 26Hz.
I would rate the speaker's nominal impedance at 6Ω. The impedance phase angle becomes highly capacitive at very low frequencies, which will make the Studio2 a challenge to drive full range with anything less than a first-rate amplifier tolerant of capacitive loads. But I had no difficulty driving it full range with the amplifiers I used, nor should this be a problem if the deepest frequencies are routed to a subwoofer. The speaker's sensitivity measured approximately 89dB/2.83V/m.
The horizontal averaged front response of the Studio2 is shown in Fig.1 (violet). This is the pseudo-anechoic response averaged over a 30° forward horizontal angle, taken at tweeter height, combined with the nearfield responses of the woofers and port.
Fig.1: Revel Studio2, pseudo-anechoic response, off-center in the horizontal plane, at 45° (red) and 60° (blue).
The Studio2's response, taken in this manner, is as good as we've ever measured. It remains within +/- 2dB across most of the range, with some very minor exceptions, and is even more tightly controlled across the vital midrange from 300Hz to 2kHz. The response falls off above 8kHz at significant off axis angles, but this is not unusual, even in the best speakers.
The bass is strong to very low frequencies, with an effective lower limit (-10dB) of 24Hz. A subwoofer is still recommended for the system, however, if your taste in films runs to major action titles played back at high levels.
Fig.2 shows the same averaged horizontal front response (violet), but this time overlaid with the vertical responses taken at +15° (red) and –15° (blue). There's little I can add that isn't evident from this result; at any reasonable ear height relative to the tweeter you'll still hear the same superb response.
Fig.2: Revel Studio2, pseudo-anechoic response at 15° above (red) and 15° below (blue) the tweeter axis.
We also measured the action of the Studio2's Tweeter Level control (also available on the Voice2. In its +/- 1dB settings it raised the tweeter response, starting at about 2kHz, to a maximum of approximately +/-2dB above 10kHz.
The Revel Voice2's minimum impedance measured 4.1Ω at 94Hz. The impedance phase angle in this case is benign, and I would rate the speaker's nominal impedance at 5Ω. Its sensitivity measured approximately 89dB/2.83V/m. The Voice2 should be an easy load to drive as long as your amp or receiver is happy with a 4Ω load.
The measured front horizontal response of the Voice2, taken on the tweeter axis and averaged in the same manner as described above for the Studio2 (but no port in this sealed-box speaker), is shown in Fig.3 (violet curve). The system is tuned to just below 100Hz and the response rolls off rapidly below about 80Hz, with an effective bass limit of approximately 40Hz (-10dB). You will definitely want to route frequencies below that point to either a subwoofer or large L/R speakers such as the Studio2.
Fig.3: Revel Voice2, pseudo-anechoic response, off-center in the horizontal plane, at 45° (red) and 60° (blue).
While the response of the Voice2 isn't quite as spectacular as that of the Studio2, it's still one of the best center channels speakers we have measured. And thanks to its three-way design, with the midrange and tweeter configured vertically in the center, there is little or no sign of the type of suckouts we see in many center channel designs in which all the drivers are arranged horizontally.
Fig.4 shows the vertical response of the Voice2 at + 15° (red) and –15° (blue), overlaid again with the averaged front horizontal response. The response at +15° is slightly better than at –15°, but the vertical off-axis aberrations at these angles are mild. And the Voice2's tilt-adjustable base can insure that the tweeter is aimed directly at the main listening area.
Fig.4: Revel Voice2, pseudo-anechoic response at 15° above (red) and 15° below (blue) the tweeter axis.
Overall, there isn't much to criticize in this excellent set of measurements.
Thomas J. Norton
All figures: Violet curve: pseudo-anechoic response on the tweeter axis, averaged across a 30° horizontal window, combined with nearfield responses of the woofers (and, in the Studio2, the port). All measurements taken at 1 meter.