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Glossary
General notes on ABS pipe:
ABS Pipe (Schedule 40 in Canada at least) is an engineered product. There is a
remarkable consistency between different manufacturers. It is physically strong and
has a high acoustic damping factor.
The tapered female flanges of the coupling pieces hold pipe securely for a temporary
fit but not so securely that pieces cannot be separated. When using ABS plumbing
glue set time is extremely short. Know that you have a good fit and reherse piecing
the work together quickly before gluing. Alternatively, use a glue which sets up
in a more relaxed manner; epoxy would work well.
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90°
Tee
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90°
Elbow
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| Commonly available in
4, 3, 2 and 1.5 stock. Sizing of drivers and baffles is the same as for elbows.
Use these elements just like the connector pieces in the old Tinker-Toy sets. 1 baffle
and 2 connected pipes or 2 baffles and 1 connected pipe. Go crazy with the possibilities. |
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Commonly available in
4, 3, 2 and 1.5 stock. When sizing drivers to fit into a baffled elbow the inside
diameter of the female pipe flanges is typically .5 larger than the inside diameter
of the elbow/pipe stock. When sizing baffle collars or box cut-outs the outside diameter
is typically 1 larger than the inside diameter of the elbow/pipe stock. |
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Hubcap
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4
x 1.5 Adapter
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| Commonly available in
4, 3, 2 and 1.5 stock. These are for solidly terminating ABS pipe. The ABS variety
are very rigid; there are some thin poly-ethelene types available but these are not
rigid enough for audio use. The ABS caps have the same inside and outside diameters
as all the other ABS pieces of a given size. |
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This gem is much more
useful than first glance suggests.
With a baffle, it forms the basis for T-line enclosures for drivers 3 and under
and aperiodic enclosures for drivers 4.5 and under (a short length of 1.5 pipe
stuffed densly forms the vent).
Without a baffle it can be used to attach a tuned piece of 1.5 pipe to other 4
stock to make a bass reflex enclosure.
4 x 3, 4 x 2, 3 x 2, 3 x 1.5, and 2 x 1.5 Adapters
Stand in the pipe section of the local harware store and piece these together like
Lego to visualize the possibilities. When a store clerk gives you static ask them
if they can help you to understand the interaction of mass loading in a tapered quarter
wave tube; I bet theyll go away and leave you to play alone. |
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