tube

[lejaybo]

hello

just another though shower

how good would a driver work in a simple tube

or

two drivers in one tube with one driver out of phase ?

[Cal Weldon]

A woofer in a concrete forming tube (cardboard) is known as a sonotube and are somewhat popular as the basis for the cabinet is already built. You just add the end pieces. Phase is another thing so you'll have to experiment with what works for you beit push push or push pull and which way you face the drivers.

[lejaybo]

i've got two ideas

one is to mount a driver at each end of a tube and using a push pull design

the second is to use two tube with the driver firing to the floor

notsure where i'm gonna get the best gain in low end

[Cal Weldon]

There are many options including a wave cannon that places a single driver part way down the tube. If you really want to go crazy, you can run two woofers isobaric and make the tube that much smaller so it's tough to give you the best suggestion without knowing more of your design goals and parameters.

[lejaybo]

basically

i''ve been wanting to build a system for music mainly
with a pair of full range satelites and a pair of sub's
i listen to music which commands low bass and i like it

i've got the satelites sorted its just the sub situation

i don;t want to build really complex cabinets i want it simple
and i though a tube design seemed like the perfect start plus
i think it'll look quite nice

also i don't have a mega budget to build the system

i'm steering towards have two sub in seperate tubes

with my satelite mounted on top

[Cal Weldon]

Sounds like a plan. Show us pics of the build when you do it.

EDIT: I've hear it's best to use a ported design with the tubes as there is less pressure build up and therefore fewer problems with your end caps.

[lejaybo]

i need tubes

anyone know and suppliers of tube in the uk?

mdf or sonotube or similar?

help me please

[Don Reid]

Hey Y'all,

Back in 1984 a good friends built subwoofers in a 24" diameter sonotubes using 18" woofers. I found that his design had much merit, and I decided to build a pair of "over the top-no holds barred" versions of a similar design.

Using JBL 2245H 18" woofers and a reflex alignment of my own devising I used the 24" diam. sonotubes not as a cabinet but as a starting point for the cabinet. The end caps are one and one-half inch void free plywood with 3/4" inside the tube and 3/4" outside. I felt that the attachment of the end caps to the sonotubes was a weak point so I made a frame work of six equidistantly spaced 1&1/2" X 1&1/2" pine struts screwed and epoxied to the inside of the sonotubes and attached in the same way to and reaching from top end cap to the bottom cap. Three additional 1&1/2" square pine braces cross the inside of the cabinet from strut to the opposing strut nearest opposite it.

The port is in the top end cap has internal cross sectional dimensions of 10"X10". It is made of 1/2" marine plywood and fits into a socket made of 1&1/2" square pine.

All totaled for both cabinets I used just over 77 linear feet of the 1&1/2" square solid pine.

The outside of the sonotubes were covered with a layer of teak grain Wilsonart and a piano black lacquer finish was applied to the exposed portion of the endcaps.

Once all of this was constructed I used about one quart of West System epoxy resin and mucho fiberglass cloth to tie all of the various pieces inside each cabinet into a single whole or monocoque.

I feel that the performance of these subs fully justifies all the time, effort and materials I put into them. I wouldn't have written such a long winded post if I didn't have more to report and another point to make.

Another friend, who at that time owned a small recording studio, was so impressed with my subs that he decided to build similar ones. He used the same JBL 2245H 18" woofers and the same bass reflex alignment, but his cabinets were just sonotubes with end caps attached.

When comparing the sound of the two pairs of subs the heavily constructed pair not only had a tighter, better controlled sound, but its usable output redached a few Hz deeper.

I still have the subs, and I believe I still have photos made during construction if anyone is interested.

Bye,
Don Reid

[jbell]

I've built MANY of this style sub. Yes weight (really the lack of it) is a sonotube's biggest downfall. When used in PA levels, usually someone has to sit on it, to keep it from walking off.


I usually sew a 'sock' and wrap the tube in grill cloth, which makes for a very professional look.

I also use a table saw to 'turn' my tops out of 1 1/2" hardwood. The top and bottom is key to making these work.

Believe it or not, I see these tops flex...

The overdamped xbl hsu driver works very well in this type of cabinet.

BTW when looking for sources, you need to look for 'Concrete Supply' companies. They have sonotubes in 12" up to 36" in diameter in 12' lengths for use in the concrete industry.

Does this help any?
http://www.kellysearch.co.uk/gb-product-123858.html

[lejaybo]

cheers Jbell i'll have a look