Sonos Play: 1 Measurements

Sonos Play: 1 Frequency Response

The frequency response for the Play:1 on-axis, 1 meter in front of the tweeter, is shown in the blue trace. Averaged response across a ±30° horizontal listening window is shown in the green trace. Generally speaking, with a speaker frequency response measurement, you want the blue (on-axis) line to be as flat as possible, and the green (averaged) response to be very close to flat, perhaps with a mild reduction in treble response.

This is performance that the designer of a $3,000/pair speaker could be proud of. On-axis, it measures ±2.7 dB. Averaged across the listening window, it's ±2.8 dB. This means that on-axis and off-axis performance are both superb and that the Play:1 should sound pretty good no matter where you place it in a room.

You can see a downward tilt from the low frequencies at left to the high frequencies at right, but my guess is that Sonos' engineers did this to keep the unit sounding full. It's a well-known (although not well-known enough!) psychoacoustic principle that rolling off the treble a bit in a product that doesn't produce a lot of bass can give a more natural perceived tonal balance.

This is a result of using a 3.5-inch midrange/woofer, which has very broad dispersion because of its small size; placing the tweeter very close to the mid/woofer, to minimize interference between the two drivers; and (I assume) application of generous amounts of equalization using the internal digital signal processor (DSP) chip.

It's practically a case study in how a product like this should be designed.

The -3 dB bass response of the Play:1 is 88 Hz, which is excellent for a speaker this small, and comparable to what I've measured from most small mini-monitors with, say, 4.5-inch woofers. Sonos seems to have put a lot of work into getting the little 3.5-inch woofer to play super-deep -- I assume by giving it lots of excursion, or front-to-back motion range, which lets it push more air and make more bass.

I also did my MCmäxxx test, cranking Mötley Crüe's "Kickstart My Heart" as loud as the unit could play without gross distortion (which in the Play:1's case was all the way up), then measuring the output a 1 meter. I got 95 dBC, which is comparable to what I've measured from many much larger AirPlay and Bluetooth systems. The Play:1 certainly plays loud enough to fill practically any home office or bedroom with sound. OK, maybe not Oprah's bedroom. But you get the idea.

By the way, I did these measurements with a Clio 10 FW audio analyzer and Clio MIC-01 at a distance of 1 meter. Measurements above 300 Hz were made using quasi-anechoic technique to remove sound reflections from the surrounding environment. Response below 300 Hz was measured using ground plane technique, with the mic at a distance of 1 meter. Results above 300 Hz smoothed to 1/12th octave, results below 300 Hz smoothed to 1/6th octave. Measurements were taken at a level of 80 dB at 1 kHz/1 meter (what I usually do for relatively small audio products), then scaled to a reference level of 0 dB at 1 kHz for this chart.

Overall, measurements for wireless speakers -- or any small speakers, really -- rarely get better than this.