- make the line length ~ 1/4 the wavelength of Fs (1/4 wavelength will be the F3
- taper the line from 1.25 -
2 Sd down to Sd at the port
- after building it, stuff the
line -- increasing or decreasing the stuffing till it sounds right. Add if the line
is too "boomy", reduce if its too lean. The stuffing increases the length
of the line (by slowing the speed of sound down to .7-.9*) and (hopefully) damps
out higher frequencies.
These rules are hit & miss.
* it is actually a taper from
wide to narrow (at the terminus) that means the line can be shorter than Fs/4
Jon Risch covers this
in the next section