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  L12 Direct Servo subwoofer
12" sealed audiophile sub
Performance & Specifications

In the chart below, with bass extension controls set to Low Music, the response is 3 db down at 18Hz. The red and blue lines are the amplitude and phase response, respectively. The phase shift as only 120 degrees. But in reality the microphone itself has 18 degrees of phase shift at 20hz. Therefore L12 only has 102 degrees phase at 20hz.

sealed response

L12 features bass extension switch allowing users to select among 3 different modes: Low Music (Q=0.5), Low HT (with a 18db/oct rumble filter at 20hz), and High (with 18db/oct bass extension at 28hz). Below is the frequency and phase response of Low HT mode. Note that the phase response (blue line) below 10hz is noisy because the response level is significantly down below 10hz.

sealed response

The comparison of all 3 modes with LINE-IN is shown below

L12 accepts a pair of LINE-IN and one LFE IN. The LFE input mode extends the upper end response to 200hz.


L12 provides a 12/24 db/oct switchable low pass filter to so that it can easily integrate with any front speakers.

Another aspect of getting a correct integration is phase alignment between the front speakers and the sub. We have written a guide on how to achieve a phase aligned subwoofer. L12 has a phase/delay adjustment knob. More >

Output, extension and user preferences

The bass extension switch allows the user to customize the deep bass extension and the rumble filter to control cone excursion. For HT application, one can set the extension to Low-HT or High for higher SPL output. For music one may prefer a lower cut off such as Low-Music setting. Changing the settings can also result in a better integration with the acoustic gain of the room.

Driver 12" high excursion with custom sensing coil
Driver materials paper cone with lightweight rubbersurround
  Aluminum flux de-modulation shorting rings
Amplifier 300WRMS class D (dual Hypex Ucd modules) patented servo controlled
Dimensions 14"(W) x 14" (H )x 15-1/2" (D) with grille and amplifier knobs
Shipping Weight 58 lbs
Frequency Response 18 - 100 Hz (-3 dB @ 18Hz, -6db@12hz) LINE-IN, 18-200hz LFE IN
12 - 120 Hz (+/-3db) LINE-IN, 12-250hz LFE IN
Crossover slope Selectable 12 or 24 dB / octave
Crossover range (Low pass) 30 - 120 Hz
Rumble Filter (High pass ) 20 Hz 18 dB / octave
Phase response 110 degrees phase shift at 20 Hz with LOW MUSIC mode
Phase adjustment 0 - 180 degrees continuously variable
Bass damping factor Low music (Q=0.5), Low-HT(Q=0.9), and high (Q=0.8)
Standy power 7W (standby, red light), 13W(ON,green light)
Finishes Available in black matte vinyl or black oak vinyl
Warranty 5 years warranty on driver and 3 years on electronics
  45 day satisfaction guarantee.
  Customers pay only one way return shipping in case of return