Soundmatters Foxl Portable Speaker System Page 3
In the Lab
Frequency response (at 1 meter) 63 Hz to 20 kHz ±3.2 dB Bass limits (lowest frequency and maximum SPL with limit of 10% distortion at 2 meters in a large room) 100 Hz at 78 dB (also maximum SPL)
Maximum full-band output approx. 86 dB at 0.5 meters approx. 76 dB at 2 meters The frequency-response graph is weighted to reflect how sound arrives at a listener's ears with normal speaker placement. Measurements were made from the left channel at 1 meter, which with a system this small is adequate to include full effects of cabinet diffraction and front panel reflections. Response of the "Twoofers" was measured on a 6-foot stand, which delivered quasi-anechoic results to about 150 Hz. Response of the woofer was made with a microphone positioned about 1/4 inch away; this response curve was scaled, then spliced to the quasi-anechoic response.
The frequency response of the Foxl looks like that of a well-engineered, $2,000-per-pair bookshelf speaker. Off-axis response is nearly identical at 10° and 20°, which comes as no surprise given that almost all the sound comes from the Twoofers and there's no crossover in the midrange region. Soundmatters deserves a pat on the back here; if you peruse other speaker reviews on Sound & Vision, you'll see that the Foxl's measured performance is superior to that of many, and perhaps most, conventional speaker systems we've tested.
Our typical bass distortion measurements, with the sound-pressure level (SPL) readings taken at 2 meters, are not really applicable to the Foxl because it's not designed to fill a room with bass. But just for kicks, I did the measurements anyway. Though close-miked measurements show bass response down to 63 Hz, there's a lot of distortion at 80 Hz and below. At 100 Hz, the unit delivers 78 dB maximum SPL at 2 meters when powered by the AC adapter. (To emulate typical usage, I placed the unit on an end table when I made the distortion measurements; this positioning reinforced the bass.) Below 100 Hz, distortion was typically about 30%.
Given the Foxl's small size and dynamic limitations, I decided to measure its overall output to get a realistic idea of what it can do in a typical hotel room. I played various types of music, turned up the level just to the point where audible distortion occurred, then backed the volume down one notch. I then measured the peak output using an SPL meter with peak hold. I made measurements at 0.5 meters (about the distance you'd listen from while sitting at a desk with the Foxl on the desktop) and at 2 meters (more like the distance you might listen from if you were wandering around the room). At 0.5 meters, results ranged from 82 dB to 86 dB depending on the recording. At 2 meters, they dropped to 71 to 76 dB. When I unplugged the AC power supply and switched to battery power, the maximum broadband SPL dropped by about 2 decibels, which isn't a big difference. However, with the AC connected, the bass at maximum output is much less distorted.