I suppose this is my first scratch project. I've built kits
over the years (crossovers prewired) and modified cabinet/
speaker combinations. Had a successful mod of some old
Nakamichi enclosures that went with their mini receiver by
replacing the woofer with the Fostex FE87e and knocking a
big hole in the backs. This worked out well and I'm using those
as my computer monitors.

I got a couple RS 1197's when they were being closed out
for (I think) $3 ea. or so. And I got on to the PVC pipe
idea because it requires few tools and no power tools at all.

The PVC's I've seen have a small baffle made of MDF. To fit
the speak to a 90d elbow, I used a toilet adapter with a
short ring of 4" diameter pipe as a baffle.

The whole thing (I've completed one for testing) consists of
RS 1197 with foam insulation as a gasket screwed to the
toilet ring and inserted into the 90d elbow. I have a line
length of only about 50 cm total and that includes a PVC t-fitting
at the base which acts as a 4" diameter port.

I intend to make the final length 101 cm as the example
project shows. But to test I just used a piece of the PVC
to see how it sounded.

The rest of this test rig is as sparse and inexpensive
at the speaks: I have a Radio Shack SA155 mini amp and a
turntable from Pioneer that a friend gave me. I purchased
a Grado Black cartridge and that's my source for now.

Playing some mono LP's through the single speak
initially gave what I felt was a muddy end to string
bass and the low frequencies in general. (This is still
the 50 cm overall length.) I've been able to smoothe
out the sound of this little driver with some dacron stuffing
in the 90 elbow and nothing else down the length of the line.

My question is: will increasing the line length to
typical TL proportions make the lower end more crisp (string
bass sounding like a string bass and less muddy?)

There's a long way to go on this but it has been a big
learning experience.

• an example of a PVC pipe speaker