Stand Loudspeaker Reviews

Sidebar 2: Measurements

I measured the frequency response in the listening window—spatially averaged to minimize room standing-wave problems—using third-octave pink noise, and measured the near-field low-frequency response with a sinewave sweep to get an idea of the true bass extension. The in-room response showed a smooth characteristic with a slightly falling trend above 80Hz, broken only by a slight excess of energy in the 3–10kHz region. The nearfield –6dB point lay at 55Hz, but, as indicated by Martin Colloms in his article elsewhere in this issue, an optimally damped small sealed-box design can still have useful in-room bass extension, and this was true for the SL6S, the response extending to 40Hz or so. It rolled off gently below that frequency, without the sudden nosedive typical of vented designs.

The impedance curve indicated the box resonance to be at 63Hz, and the lowest point reached was 6 ohms, suggesting that the SL6S will be relatively easy to drive.&#151John Atkinson