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  F18 Direct Servo subwoofer
18" sealed audiophile sub with 900WRMS amplifier
Performance & Specifications

F18 is designed to be compatible with other sealed subwoofers from our product lines. With 12hz and high damping setting, it is frequency response is very similar to that of F15HP/E15HP. In the following are the plots for both frequency response and phase response. Phase alignment is very important when integrating multiple subs. It is our objective that all of our sealed subwoofer models have similar low end frequency response and phase response.

sealed response

Fig 1.0 - F18 Frequency response chart with line-in 12hz high damping

sealed response

Fig 1.1 - F18 Frequency and phase response chart with line-in 12hz high damping

The high (low) damping setting has the most gradual (steep) roll-off. For movies, we recommend mid damping or low damping.

Fig 1.2 - Comparison of F18 Frequency response of all 3 different damping settings at12hz

F18 also has a rumble filter with -6db @10hz. This is suitable for playing the intro scene in movie Edge of Tomorrow. Fig 1.3 shows the frequency response and phase shift of this rumble filter. Rumble filter should be turn on for maximum SPL playback at all times.

Fig 1.3 - F18 Frequency response of the selectable rumble filter


One important aspect of getting a correct integration is phase alignment. We have written a guide on how to achieve a phase aligned subwoofer. More >


Driver DS1820 18" high excursion with custom sensing coil
Driver materials One piece black anodized dish aluminum with rubber surround
  Cast aluminum basket
  Multiple aluminum flux de-modulation shorting rings
Amplifier 900W RMS Hypex class-D patented servo controlled
Dimensions 20-1/2"(W) x 20-1/2" (H )x 21"(D) - (23" D with grille and heatsink)
Shipping Weight 140 lbs (125lbs gross)
Frequency Response 14 - 200 Hz (0db/-2db) with LFE inputs
10 - 250Hz (+/-3db) with LFE inputs
14 - 90 Hz (-2 dB @ 14 Hz) with LINE IN inputs
Crossover slope Selectable 12 or 24 dB / octave (PEQ and XLR versions)
Crossover range (Low pass) 25 - 100Hz
Rumble Filter (High pass ) 12 Hz 18 dB / octave (-6db @10hz)
Phase response 90 degrees phase shift at 20 Hz (measuring mic has 18 degrees shift)
Phase adjustment 0 - 180 degrees continuously variable
Bass damping factor settings high (Q=0.5), med (Q=0.7), and low (Q=1.1)
Finishes Available in black oak and black matte vinyl
Warranty 5 years warranty on driver and 3 years on electronics
  45 day satisfaction guarantee