Test Bench: JL Audio Fathom f112 Subwoofer
In the lab
Frequency response (at 2 meters) 24 to 101 Hz ±2.5 dB Bass limits (lowest frequency and maximum SPL with limit of 10% distortion at 2 meters in a large room) 16 Hz at 80 dB SPL 108 dB average SPL from 25 to 62 Hz 114 dB maximum SPL at 62 Hz bandwidth uniformity 94%
I measured the JL Audio Fathom f112 subwoofer's bass limits with it set to maximum bandwidth and full gain and placed in the optimal corner of a 7,500-cubic-foot room. In a smaller room, users can expect 2 to 3 Hz deeper extension and as much as 3 dB greater sound-pressure level (SPL).
The f112 has fairly high output (109 dB or greater at every frequency from 32 Hz upward) and good uniformity of output across its operating range. The subwoofer comfortably handled 16- to 20-Hz signals without exceeding our 10% maximum distortion limit, with its low-end limit measuring 16 Hz, where it produced 80 dB SPL. Maximum SPL (114 dB) was achieved at 62 Hz.
Although the crossover control is marked from 30 to 130 Hz, the true acoustic operating range was 60 to 92 Hz when the LP Filter was employed. Crossover slope was 18 dB/octave when the control was set to either Off or 12 dB; the slope measured 12 dB/octave when the setting was 24 dB. The ELF (extra low frequency) trim feature added 1.9 dB of SPL below 70 Hz when set to +3 dB. When the ELF trim was set to -12 dB, level began decreasing at 100 Hz and reached a maximum cut of 12 dB at the lowest frequencies. The ARO (Automatic Room Optimization) routine would not always fully complete when the microphone was more than 3 meters from the subwoofer and did not always make the optimal adjustments, as verified with MLSSA measurements. Users should listen with and without A.R.O. to confirm their results.