"Old Nick" wrote in message

Don't forget air ports. Subwoofers need a lot of air, and they can be
damaged by the pressure difference between inside and outside at higher
volumes. (Don't ask me how I know)

Can you describe that? Serious. I have seen speakers blown by too
_little_ back pressure (over excursion) caused by ducts.

What happened?

Driver design ... some drivers are designed to be ported, others not. There
is a good deal of magic/art in correct porting of a specific driver for a
certain sound and the size of the box, despite the physics involved and the
manufacturer's recommendations. I used to build my bass cabinets based on
the old Dietz design, which was a favorite for bass players in the "old
days" and I experimented with many different porting sizes and designs on
most of them ... AAMOF, I still play through an old Altec 15" bass speaker
in an original Dietz box that I customized the porting on..

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Last update: 7/10/04