Posted by lon [ 209.103.193.224 ] on March 17, 2004 at 21:31:15:
In Reply to: Re: Boomtoobz posted by Martin on March 17, 2004 at 20:12:17:
Hello Martin,
Thanks for your gracious reply to a newbie.
The link below you might well be familiar with from James Melhuish'
Full Range Driver site.
I started out with that design. So I had one ten foot length that I was going to cut down to the proper length for 2 speaks with RS 1197 drivers. I didn't know what I was doing so I made some baffles from closet fittings because the cutout was the right size. To get the
fittings attached to the 90d elbow I used a short length of the
4" diameter PVC glued onto a closet flange.
Before cutting down the rest to make 2 speakers I assembled
one complete speak with the entire reamining length. This was
a little over 7 feet. Unlike the PVC Periscope, my port at the
base was a 4" tee fitting. So port is the same diameter as
the pipe and faces front.
Listening to this configuration was a gas during the weekly organ
recital on Wisconsin Public Radio. I loved the depth of the sound
rigth away. After all, I had been reading about speaker designs for years but had no listening opportunities. I then tried out some electronic music from Steve Roach and Tangerine Dream too. These
listening tests were also good.
But I still had this Wilt The Stilt speaker nowhere near
ear or listening height. It took me a few days to realize that a second tee fitting at the bottom coupled to the port on the
base would allow me to cut the pipe down while retaining the
overall line length.
To get the idea of what the assembly looks like, imagine you are on the deck of a cruise ship near some stacks that protrude through the deck: one is 5 ft high and there's another 3 ft length in front of it coupled at the base. There's some other flanges and stuff holding the thing upright on some MDF squares with through bolts and t-nuts.
Wayne was wondering how the harmonics would work and I was wondering which is the best way to tweak them. The only interior treatment is a couple 12" squares of pillow stuffing directly behind each driver.
If I had to put a number on it, the length of the boomtoob
from driver to port is about 8.5 ft. Not much sound pressure
at the port end but it is definately noticeable.
A fellow over at the t-line discussion has also done
some assemblage of PVC. Those interested can look for the
piece called "Laying Pipe with Audio Leggo" at the t-line
site.
But I have not seen anything like what I put together.
It may be goofy and impractical to duplicate, but I was looking for something to build with a minimum of tools. I have no shop and live in an apartment. So a hack saw and some other hand tools are all I've used.
I have one of the boomtoobz completed and there is another
of 5 ft. length from the original design so some comparison listening can be done. Perhaps 2 boomtoobz would be too many?
Many questions remain. :-)
lon@athenet.net