Amina ALF40 User manual

USER GUIDE
ALF40 Bass Enhancer
(V2.1 Mar 2010)

2
Contents
Using the adjustable port system page 3 –5
Positioning the ALF40 page 6 –7
ALF40 connection options page 8 –11
Setup tips page 12
Specifications page 13

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Using the Adjustable Port System
The ALF40 features a unique port system which allows for great flexibility
in positioning and concealing the product.
The port can be switched between two optional positions in the ALF40’s
cabinet. An aluminium plate [port plate] and rubber o-ring provides an air-
tight seal around the port. A similar plate is used to cover the unused port
hole [blanking plate].
WARNING:
BE CAREFUL NOT TO DROP ANY OBJECT INTO THE ALF40
ENCLOSURE THROUGH THE PORT HOLES.

4
Top Position
This port position can be useful if you need to stand the ALF40 on its end
(connection terminal facing upward).

5
End Position
IMPORTANT NOTES:
ALWAYS loosen the 4 screws in the port plate before adjusting the
port
the blanking plate MUST always be screwed down over the port
position that is not in use
be sure to tighten both the port plate and the blanking plate. NEVER
over-tighten the screws
ensure that the RUBBER O-RING is correctly in position around the
plastic port and sitting in the circular rebate.

6
Positioning the ALF40
Free Standing
The ALF40 can be positioned anywhere in the room. A location near the
corner of the room will give the most bass output. It is important to allow
the bass port to “breathe” i.e. do not place any solid objects closer than
50mm (2”) directly in front of the port. You may place the ALF40 in any
orientation that doesn’t block the port.
Concealed Placement
The ALF40 may be placed inside a cupboard or other piece of furniture,
behind wall panelling or even within a ceiling cavity. Whatever structure
you install the ALF40 inside, it is important to create a suitable hole for the
port to protrude through so that it may “breathe” into the listening room.
There are 3 brackets supplied with the ALF40. These may be used to secure
the ALF40 to a structure.
Please use wood screws not longer than 12mm (1/2”) to fix the brackets to
the ALF40 cabinet.

7
In-Ceiling
The illustration below shows how the supplied brackets can be used to fix
the ALF40 to a ceiling joist.
Notice the port protrudes from the cabinet –this is to allow it to protrude
through a suitable hole cut in the plasterboard ceiling layer.
A suitable lighting trim may be placed over the port opening to improve its
appearance.

8
ALF40 Connection Options
Passive 2.1: The output of an ALF40 in most situations will match a pair of
AIW1X or AIW3X speakers (2x ALF40 might be necessary to match a pair
of AIW3X in a large room). The ALF40 is designed to be connected in
parallel with an AIWX series speaker (the APU2 forms part of what is
effectively a crossover between ALF40 and AIWX). In this scenario, one of
the amplifier channels (Left or Right) is used to drive the ALF40 and one of
the AIWX speakers together. It is assumed that bass frequencies are
normally mixed in mono; however for orchestral music better performance
will be obtained with the ALF40 connected to the Left channel of the
amplifier.

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Passive 2.2: For systems using a pair of AIW5X speakers, a pair of ALF40s
will be necessary. In this scenario both channels of the stereo amplifier
drive an ALF40 in parallel connection with an AIW5X.

10
Active 2.1: By connecting a single ALF40 to its own amplifier channel, its
output relative to the AIW1X/AIW3X pair can be set optimally. In larger
rooms care should be taken not to adjust the relative output of the ALF40
so high that its mechanical limits are reached well before those of the
accompanying AIWX speakers –consider using two ALF40s if this is the
case [see Active 2.2].

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Active 2.2: For systems using a pair of AIW5X speakers, a pair of ALF40s
will be necessary. In this scenario the amplifier will need four independent
channels.

12
Setup Tips
When setting up any of the above system scenarios, it is advised to
experiment with connecting the ALF40 in reverse phase with respect
to the AIWX series speakers. Often, the reverse phase connection
results in better integration and slightly higher sound pressure level
through “cross-over” region.
In scenarios 2 and 3 only, a maximum of two ALF40s may be
connected in parallel to a single amplifier output [amplifier must be 4
ohm stable]. This will help provide the correct low frequency sound
pressure levels in large rooms without needing additional amplifier
channels.
Where there is more than one pair of AIWX speakers in a room,
decide which of the above scenarios is applicable to the system and
multiply the number (e.g. 2.1) by the number of speaker pairs.
Example: a large reception room requires four AIW3X speakers and
the amplifier has provision for up to 6 independent amplifier
channels. Therefore this could be an Active 4.2 system (2.1x2 = 4.2) or
a Passive 4.4 system (2.2x2 = 4.4) depending on how much bass
output is required.

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Specifications
Dimensions: 358 x 159 x 134mm (14.2” x 5.3” x 6.3”)
Weight: 3.03Kg (6.67 lbs)
Design: Ported, acoustic bandpass with built in
protection circuit
Power handling: 40W continuous
Nominal Impedance: 8 Ohms (4 Ohm when used in passive
configurations with AIWX speakers)
Frequency Response: 60Hz - 150Hz (+/-6dB), 24dB/octave slope
Sensitivity: 88dB @ 1m/2.83V RMS
Maximum SPL/1m: 103dB
Port location: Front or end convertible, length adjustable
Port diameter I.D/O.D: 39mm (1.55”)/43mm ( 1.7”)
Connection: 3-way binding post (accepts 4mm plugs)

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Amina Technologies Ltd
Cirrus House, Glebe Road
Huntingdon, Cambs, PE29 7DX England
tel: [phone], fax [phone]