Skip to main content

ALF 40

The entry-level passive bass-enhancer that can add warmth to music and television whilst remaining easy to install into a ceiling or into cabinetry.

Using a 4th order bandpass design, the ALF40 can play at medium level whilst only having a small circular visible vent into the room.

Built in filtering and protection circuits mean that the ALF40 can be powered from a 60W amplifier delivering full-bandwidth content.

Product Description

Utilising a unique adjustable ported design, the ALF40 bass-enhancer easily blends into any room environment by mounting within walls, ceilings, cabinets or other joinery with minimal visual impact. This passive 30W subwoofer can deliver 106dB SPL/1m down to 65 Hz making the ALF40 discreet bass-enhancer ideal for distributed audio systems.

The ALF40 is provided with metal mounts for mounting directly to studs/joists, and is designed to be connected directly to a dedicated full range amplifier output. No additional filtering is required when used in conjunction with Amina Invisible loudspeakers.

Example Applications

ALF40 may be installed in wall/ceiling cavities where there is a minimum 134mm depth. The adjustable port tube can be allows the ALF40 to vent straight into the room rather than into the cavity. ALF40 may also be installed into cabinetry, behind kickboards, under furniture or even inroom.

Frequency Response


ALF40 can be mounted directly to stud frame using the supplied metal mounting L-mounts.

Port tube can be relocated to one of 2 port-opening positions and can have it’s length adjusted to perfectly match the depth of the ceiling void (maximum adjustment 80mm).

Note: Port tube can be adjusted, but should never be replaced, bent, extended or blocked. Doing so will impact the performance of the subwoofer.


Being a passive unit, the ALF40 requires external amplification. Given that both protection and filtering are both built in to the subwoofer itself, the unit can be powered by a 60W amplifier delivering full-bandwidth content.

The ALF40 can be powered by its own dedicated amplifier channel, alternatively it may be wired in parallel to a single Amina VPT loudspeaker panel.

Note: Please take care to match total impedance load to the amplifier when wiring subwoofers and speakers in parallel. It is not wise to wire two subwoofers in parallel to each other, however it is possible to wire an 8 Ohm subwoofer in parallel to an 8 Ohm loudspeaker panel without affecting overall load that the amplifier will see. For example, the ALF40 can be wired in parallel to an iQ3 and still appear as an 8 Ohm total load.


Nominal Impedance
8 Ohms
Power Handling
88dB 1m/2.83Vrms (half space)
88dB 1m/2.83Vrms (half space)
Frequency Response
65Hz - 155Hz (±6db) (4th order bandpass)
Electrical Connection
Sprung Terminal
Product Weight
3.2Kg (7lbs 1oz)
Fixing Requirements
Mounting mounts (included)
359mm x 157mm x 134mm (141/8" x 63/16" x 51/4”)
Port Location
Front and end-fire, adjustable port location options