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Intro
Most woofers just don’t quite do the lowest
octave. You read the specs that say "usable response: 20 Hz – 20 KHz" and you know that
the 20 Hz part of it is wildly optimistic. Achieving very low frequencies at reasonable power levels
is not an easy job; the acoustic impedance experienced by a speaker cone declines as the inverse of
the square of the frequency. As a practical matter, woofers and their enclosures need to be very large
to properly reproduce the lowest octave. Even when you compensate with frequency equalization and more
amplifier power, the performance suffers as you reach the excursion and power handling limitations of
a small cone in a small box.
Let’s face it. Size does matter.
This is the saga of El Pipe-O, an adventure in
over-the-edge woofer construction. The name El Pipe-O came from its striking resemblance to a
legendary smoking appliance belonging to one of Pass’s roommates in college that was the object of
worship by a small cult.
El Pipe-O consists of very large woofers mated
to large cylindrical transmission lines. The goal is to get good powerful response down to 20 Hz at
levels where the room starts to rattle before the loudspeaker.
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