Sonus Faber Venere Speakers and REL T-7 Subwoofer Page 5

Test Bench

Frequency Response

  • tower 41 Hz to 20 kHz ±6.2 dB, ±5.5 dB 200 Hz to 10 kHz
  • center 61 Hz to 20 kHz ±4.8 dB, ±1.9 dB 200 Hz to 10 kHz
  • mini 54 Hz to 20 kHz ±5.4 dB, ±2.5 dB 200 Hz to 10 kHz
  • sub 29 to 103 Hz ±3.0 dB

Sensitivity (2.83 V @ 1 meter, 300 Hz to 10 kHz)

  • tower 86.5 dB
  • center 90.2 dB
  • mini 81.9 dB

Impedance (minimum/average)

  • tower 3.1/6 ohms
  • center 3.1/6 ohms
  • mini 5.3/11 ohms

Bass output, tower (CEA-2010A standard)

  • Ultra-low bass (20-31.5 Hz) average: 95.3 dB
    • 20Hz: 84.3 dB
    • 25 Hz: 94.2 dB
    • 31.5 Hz: 100.6 dB
  • Low bass (40-63 Hz) average: 112.2 dB
    • 40 Hz: 107.9 dB
    • 50 Hz: 111.4 dB
    • 63 Hz: 115.6 dB

Bass output, subwoofer (CEA-2010A standard)

  • Ultra-low bass (20-31.5 Hz) average: 97.7 dB
    • 20 Hz: 74.0 dB
    • 25 Hz: 93.9 dB
    • 31.5 Hz: 104.9 dB
  • Low bass (40-63 Hz) average: 112.3 dB
    • 40 Hz: 111.9 dB L
    • 50 Hz, 113.3 dB L
    • 63 Hz: 111.5 dB L

Bass limits

  • center 40 Hz at 96.6 dB
  • mini 40 Hz at 87.9 dB

I measured the Venere speakers with the microphone placed at a distance of 2 meters, using quasi-anechoic technique to remove the effects of reflections from nearby objects. I measured the Center and the 1.5 on a 2-meter-high stand, and the 2.5 sitting directly atop my measurement turntable, in both cases piling attic insulation on the ground to eliminate sound reflections from the ground. I adjusted the microphone position for the flattest on-axis response, then averaged the measurements at 0°, ±10°, ±20°, and ±30°, smoothed to 1/12th octave. Bass response of the Venere speakers and the REL subwoofer was measured using ground plane technique with the microphone on the ground 2 meters from each speaker; this was smoothed to one-third octave, then spliced to the quasi-anechoic measurements at 200 Hz. Results are normalized to 0 dB at 1 kHz. All frequency response measurements were made with a Clio FW audio analyzer and then imported into a LinearX LMS analyzer for post-processing.

All three of the Venere speakers show a downward tilt in their tonal balance, with a mildly rolled-off treble. The 2.5 tower and 1.5 mini both show a fairly large resonant peak at about 100 Hz, which makes their measured specs worse but gives them a lot more bass output. Both the Center and the 1.5 mini measure impressively flat in the critical range between 200 Hz and 10 kHz — especially the Center, which runs ±1.9 dB through most of the audio band. I couldn’t get such good results from the 2.5 tower, though. Its frequency response numbers are thrown off by a big response dip at 2.9 kHz. Given that the tweeter crossover point is specified at 2.5 kHz, I have to suspect this is a cancellation effect between the midwoofer and the tweeter. Interestingly, the 2.5 tower has a much higher crossover point than the other speakers: 2.5 kHz, vs. 2.0 kHz for the 1.5 mini and 1.8 kHz for the Center, even though the 2.5 has a larger midwoofer that would seem to mandate a lower crossover point. I have to think this has something to do with its anomaly at 2.9 kHz in the averaged response.

Off-axis response for all models is very good — especially for the 1.5 mini, whose response at ±30° looks almost the same as the on-axis response. The 2.5 tower looks almost as good off-axis, with just a slight dip in the midrange emerging as you move to ±30° or further off-axis. Most woofer-tweeter-woofer center speakers show pretty bad interference effects between the woofers when you move off-axis, but the effect with the Center is comparatively mild: just a fairly narrow dip of about 10 dB centered at 1.45 kHz.

All of these measurements are with the grilles off. Adding the grilles produces only a mild difference at high frequencies: a narrow dip of about 5 dB at 8 kHz for the 2.5 tower and 1.5 mini, and a dip of 2 to 4 dB between 8 and 10 kHz for the Center.

Impedance is a little on the low side for the 2.5 tower and the Center. The former drops to a low of 3.1 ohms/-22° phase at 96 Hz; the latter to 3.1 ohms/-15° at 10 kHz. Surprisingly, the 1.5 mini’s impedance is much higher, with a minimum of 5.3 ohms/-5° at 163 Hz. The 2.5 tower’s low impedance and the 1.5’s low sensitivity means these speakers should be partnered with a powerful, high-quality amplifier; I’d recommend 100 watts or more per channel into 8 ohms for best performance, with double the power (or close to it) at 4 ohms for the Venere 2.5. The center speaker, surprisingly, is much more sensitive than the others, but that’s good — some experts contend that you need 3 dB extra headroom in your center channel relative to the front left and right channels.

I did CEA-2010A output measurements for the REL T-7 and the Venere 2.5 tower. Both were taken at 3 meters and then scaled up so that they are equivalent to 1-meter results. An L next to a measurement indicates that the maximum level was dictated by the subwoofer’s limiter. Bass output of the Venere 2.5 when powered by an Outlaw Model 2200 amp was impressive for a fairly compact tower speaker — in fact, it’s close to that of the REL T-7. Not many passive tower speakers of this size can deliver measurable CEA-2010 results down to 20 Hz. The REL T-7 also measures pretty well for its size, and also produces measurable CEA-2010 results down to 20 Hz.