It is important that the cabinet is airtight and doesn't vibrate uncontrollably.
The most suitable materials are:
- Chipboard (inexpensive, however, treatment of the rough surface is rather
complicated and time consuming.
- MDF panels (about 50% more expensive, but with a smooth surface and edges)
Quite suitable are also cabinets made of bricks, concrete or stone - they
are, however, difficult to handle.
In order to suppress unwanted vibration internal bracing panels should be
fitted to the cabinet (2 to 3 panels for a 80 x 225 x 25 cm cabinet). At least
one supporting panel should be fitted in a right angle (preferably in the
centre) to the panel running over the full height of the cabinet.
Removable parts should be sealed with car putty, adhesive sealing (e.g. window
sealing) or our driver sealing tape (-> damping material). Non-removable
wooden parts should be put together using wood-glue or even better structural
First you need to prepare all panels and drill the necessary holes. If not
indicated otherwise the bass reflex opening should be close to the bass driver.
The midrange driver / tweeter should be even closer to the bass driver, otherwise
- depending on the listener position - volume differences in the crossover
frequency range will develop.
The individual drivers have to be connected to the crossover. It's essential
to connect the drivers with the correct polarity. Every driver's plus terminal
is marked, usually with a red dot (or e.g. with a white flag like Peerless
WA 10). The driver's plus pole may also be determined by connecting the plus
pole of a small battery to it. In this case the driver's cone should move
The crossover's plus pole is tagged as well, either with a "+" or a red marker.
If you design the crossover yourself it's not that important that all speakers
are connected with the correct polarity. It is, however, absolutely mandatory
that the polarity of each driver of one loudspeaker corresponds with the drivers'
polarity of the other loudspeaker.
Important: the correct connection of
Please pay attention to connect the tweeter to the correct "tweeter" terminals
of the crossover. If the tweeter is connected to the bass driver terminals
by mistake then the tweeter's voice coil will be destroyed, should the volume
of the amplifier be increased carelessly.
Bass reflex tube:
There is an elegant solution to tune bass reflex speakers: the longer the
tube the tighter the bass. The shorter the tube the boomier the bass. If you
intent to position the speaker close to a wall, the tube should be longer,
since walls enhance bass. On the other hand, the tube should be shorter when
the speaker is placed in the centre of a room.