Test Report: Wharfedale DX-1 Speaker System Page 3

Bottom Line

In the DX-1, Wharfedale seems to have put fidelity first and foremost, without making any of the compromises that could have gotten greater output from the system. If you’re looking for an inexpensive yet extraordinary system for a bedroom or small den, I can’t think of another I’d recommend more highly. Just don’t push it beyond its limits.

Test Bench

Frequency response
• satellite 100 Hz to 20 kHz ±2.8 dB
• center 100 Hz to 20 kHz ±5.1 dB
• subwoofer 37 to 122 Hz ±3 dB

Sensitivity (SPL at 1 meter with 2.83-volt signal)
• satellite 80.7 dB
• center 82.6 dB

Impedance (minimum/nominal)
• satellite 3.7/7 ohms
• center 82.6 dB

Bass limits
• satellite 80 Hz at 81 dB
• center 80 Hz at 84 dB

Bass output, subwoofer (CEA-2010 standard)
• Ultra-low bass (20-31.5 Hz) average: NA

20 Hz, NA
25 Hz, NA
31.5 Hz, 88.9 dB

• Low bass (40-63 Hz) average: 108.3 dB
40 Hz, 103.7 dB
50 Hz, 110.1 dB
63 Hz, 109.8 dB

I measured the Wharfedale DX-1 satellite and center speakers atop a 2-meter-high stand with the measurement microphone at a distance of 1 meter from the fronts of the speakers. The curves you see here represent an averaged quasi-anechoic frequency response from 0° to 30°, smoothed to 1/12th of an octave. To get the low-frequency measurement for the satellite, I close-miked the woofer. For the center, I close-miked the woofers and port and summed their responses. I then spliced the bass responses to the averaged responses at 240 Hz. I measured the response of the subwoofer by close-miking the woofer and ports, then summing their results. Frequency response curves for the satellite and center are normalized to 0 dB at 1 kHz, and the curve for the subwoofer is normalized to peak at +3 dB.

The satellite speaker measures great. In my opinion, anything that measures with less than ±3-dB variance on our averaged response curves is a well-engineered speaker, and the satellite measures ±2.8 dB. The only major response error is a 3-dB dip at 2 kHz. Off-axis response is also great. At 45° and 60° there are no major response anomalies, just a very gentle treble rolloff. Adding the grille caused only subtle response changes, except for a reduction in treble averaging 2.5 dB between 9.5 and 15.8 kHz. Bass output isn’t great, but it’s adequate to blend with the sub; turns out 120 Hz was a good choice of crossover point.

The center’s on-axis response is almost as good as the satellite’s (±3.2 dB), but its averaged curve doesn’t look as good because interference between the woofers causes a broad dip between 1.8 and 8 kHz. This dip shouldn’t cause overt colorations in the midrange, but it could make the treble and lower mids sound a bit emphasized (unless you have absorptive material on the side walls of your room). Off-axis response is typical for a woofer-tweeter-woofer center speaker — at 45° and 60°, a dip of 10 to 20 dB appears between 1 and 4 kHz, and at 60° the response dips by 13 dB at 10 kHz. The center’s grille caused a treble reduction averaging 2.5 dB between 11.3 and 17.8 kHz, but no other significant changes in response. Impedance (see chart) of the satellite and center drops a little low for inexpensive speakers (which will presumably be connected to an inexpensive receiver), but it should be manageable. For the satellite, it drops to 3.7 ohms at 285 Hz with a phase angle of +7°. For the center, it’s 3.7 ohms at 265 Hz and +4°. Sensitivity is low, though. Average of on-axis quasi-anechoic output from 300 Hz to 10 kHz runs 80.7 dB for the satellite and 82.6 dB for the center. It’s unlikely you’ll be playing this system real loud, so I imagine most inexpensive receivers can drive these speakers with no problem. I probably wouldn’t recommend using the DX-1 system with one of those all-in-one DVD player/receiver components that come with many mass-market HTiB systems, though.

The subwoofer’s frequency response goes up to 122 Hz, just enough to mate properly with the satellite and center. Combined low-pass function of the subwoofer’s crossover and driver is -19 dB/octave. I measured the DX-1 subwoofer’s output using the CEA-2010 technique, outdoors at 2 meters, and added 6 dB to each result to simulate measurements at 1 meter. For such a tiny sub, output is pretty good in the low bass (40-63 Hz) octave, but it drops quite a bit at 31.5 Hz and there’s no measureable response at 25 or 20 Hz. (The average low bass response is calculated in pascals, as per the updated CEA-2010A standard. Calculated by the original CEA-2010 standard, it would be 107.9 dB instead of 108.3 dB — an insignificant difference.) Note that none of the results was dictated by a limiter, so either the limiter threshold is set very high or a limiter isn’t present.