Subwoofers

Paradigm Reference Signature Sub 25 Subwoofer and Perfect Bass Kit Software (PBK-1)

ARTICLE INDEX

On the Bench

All bench tests were performed with the Sub 25 in the middle of the listening room, to avoid interaction with corners or walls. Except as noted below, measurements were taken from 1 foot at a height equal to the center of the speaker grille.

Paradigm Reference Sub 25 powered subwoofer and Perfect Bass Kit (PBK-1)

Distortion at 20 Hz and 100 decibels was a very good 6.5%.

Paradigm Reference Sub 25 powered subwoofer and Perfect Bass Kit (PBK-1)

Subwoofer output is generally considered clipping at 10% distortion; I wanted to see how much I could get from the Sub 25 at 20Hz before reaching the limit. How about 108 decibels at 20Hz? Keep in mind, that was measured mid-room without any benefit from wall or corner placement, which typically adds between 3-6 decibels of useable output.

Paradigm Reference Sub 25 powered subwoofer and Perfect Bass Kit (PBK-1)

Below is the graph for THD+N vs. Frequency. It was set at 100 dB output at 50 Hz at 1 foot, then the test was started. At 15 Hz, while technically clipping at 13.5% THD+N, the Sub 25 produced a robust 93 decibels with no audible distortion or distress. Paradigm's product sheet for the Sub 25 states "low frequency extension 9 Hz (DIN)," but I could not reproduce usable output at or below 10 Hz during my bench tests. To summarize, the subwoofer stayed below 5% THD+N from 23 Hz to about 160 Hz, which is excellent.

Paradigm Reference Sub 25 powered subwoofer and Perfect Bass Kit (PBK-1)

As noted above, the Sub 25 was technically clipping (10%) from 10-15Hz, with distortion of about 6% at 20Hz before dropping off at higher frequencies

Paradigm Reference Sub 25 powered subwoofer and Perfect Bass Kit (PBK-1)

Frequency response is shown at one foot (red), one meter (blue), and two meters (yellow). Notice how flat the response curve performance stays even as the measurements are taken farther away from the sub. That is excellent performance.