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ALF 120

The passive subwoofer that can play the loudest and lowest whilst remaining easy to install into a wall or ceiling.

Using a Distributed Transmission Line design using an array of 4″ drivers, the ALF120 packs a punch whilst staying incredibly slim. At only 118mm thin and 345mm wide, it is designed to fit into a cavity wall or ceiling.

Requiring a DSP amplifier (or suitable system processor), the ALF120 can play down to 27Hz at 111dB at 1m from just 50W. This makes the subwoofer perfect for great music systems but also media rooms and home theatres.

Product Description

Utilising a highly efficient Distributed Transmission Line design, the ALF120 is the perfect discreet subwoofer for installation into walls, ceilings or cabinetry. This passive subwoofer is capable of reproducing frequencies down to 24Hz at an incredible 111dB from just 50W, all with excellent accuracy, low group delay and minimal distortion. Only 118mm deep and porting through a slot designed to vent discreetly through an opening in the skirting board, the DTL design allows for easy installation into standard cavities while giving incredible sonic performance.

In order to protect the subwoofer once installed and to help achieve accurate audio integration into the audio system, the ALF120 must be used with a DSP amplifier or separate processor.

Example Applications

ALF120 subwoofer installs straight into cavity walls, ceiling voids or furniture with a minimum cavity depth of 121mm, porting directly into the room through a slot vent which is to be cut in skirting board, ceiling or cabinetry as per installation guide. Port location may be adjusted to allow for an ‘end-fire’ installation, specifically designed to allow the ALF120 to be installed flat, into furniture.

Frequency Response


Designed to be fitted into a cavity wall with 16″ spaced studs (on centre), the ALF120 is mounted using felt pads which not only hold it securely in place, but also mechanically decouple the cabinet from the structure of the property, allowing all sound energy to be effortlessly ported directly into the room and not into the rest of the structure.

It is also possible to install into a ceiling void or into furniture if this helps to further remove the slotted vent from the eye-line of the listener.


Being a passive subwoofer, the ALF120 requires external amplification, however due to the Distributed Transmission Line design using 4″ drivers, it requires DSP to maximise performance and ensure it continues to perform for a lifetime.

Either requiring a dedicated DSP amplifier or a system processor and ‘dumb’ amplifier combination, the requirement is for 3 bands of parametric EQ, 48dB/Octave bandpass filtering and absolute voltage limiting. For information on a suitable amplifier or processor, please contact your distributor.

Note: Failure to use adequate DSP protection may result in warranty becoming void.


Nominal Impedance
6 Ohms
Power Handling
96dB 1m/2.83Vrms (quarter space)
96dB 1m/2.83Vrms (quarter space)
Frequency Response
27Hz - 120Hz (±6db) 48dB/Octave bandpass
Electrical Connection
Push Terminal
Product Weight
17.5Kg (38.5lbs)
Fixing Requirements
Felt isolation-pads (included)
In-line Protection unit
External DSP protection (voltage limiting) - Not included
1605mm x 345mm x 118mm (633/16” x 131/2” x 43/4”)
Port Location
Front or end-fire location options