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.
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.
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
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
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
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
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
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
Attachments
Are these downfiring? I am building some downfiring subs with 12 inch Peerless XXL's in a cylindrical enclosure. How far should they be above the floor? The only info I have found is someone saying that the area of the opening (the height above floor * circumference of the enclosure) should be at least equal to the driver area. What do you guys think?
TIA,
Jan Didden
TIA,
Jan Didden
I found a useful increase in the bass from my subs (sealed) by using that rule of thumb; this allowed me to reduce the EQ somewhat (about 2-3dB less at 18 Hz with a concrete slab floor). Less than that, I saw some odd bandpass effects, probably because of slot-loading the front radiation. I suppose I could rejigger the EQ to compensate...
The subs aren't in use now because we're in a temporary apartment, but when we move into a house next month, it will be interesting to see what effect a wooden floor has compared to concrete.
The subs aren't in use now because we're in a temporary apartment, but when we move into a house next month, it will be interesting to see what effect a wooden floor has compared to concrete.
It might be fun to play with that distance. I used three discrete steps, with some furniture legs from the hardware store. The shortest had just enough clearance for the surround plus X-max, the tallest were about 15cm.
It's probably been warmer here the past few weeks than it is there. Right now (0733), it's slightly below zero C; and it will get up to 10 later. The house we've found has a nice cellar for the wine and a front room that will accommodate my dynamic speakers. Alas, the ceilings are still too low for my ESLs.
It's probably been warmer here the past few weeks than it is there. Right now (0733), it's slightly below zero C; and it will get up to 10 later. The house we've found has a nice cellar for the wine and a front room that will accommodate my dynamic speakers. Alas, the ceilings are still too low for my ESLs.
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