latest project TB 3" bamboo

Hey guys,
Just wanted to show off the latest project. Had the idea for a while but finally found what I needed to make it happen plus a little motivation from an earlier thread where one of you guys made speaker enclosures out of bowls found at Target.

So I needed some computer speakers and made this. I found 7" salad bowls at Bed, Bath, and Beyond store. They came in a set of four and all about the same size. I added a spacer to make them evenly round and added some cotton fill inside. The drivers are Tang Bang 3" bamboo. Also made a wooden donut for the base so they can be positioned at any angle needed.

Got to tell you they surprised me. A little 3" driver and it kept up with all kinds of music I put through them. I am running them on a Harmon Kardon receiver for right now. They sound smooth and not fatiguing at all. I listened to them at work all day. Actually I was thinking of making three more and trying them out as an HT setup. So what do you guys think? Any ideas to improve on the enclosure?

John
 

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AnthonyPT

Member
2004-10-29 9:23 am
Hi Kazoo

You have just done what I have been
thinking of for X years Very nice
and I am sure the Bamboo units work
well. I use counterweights in a foam
core for balance as I used non Neo
Tang Band drivers. Have seen similar
sorts of bowls in Ikea. Picture is
of my sphere experiments in Paulownia,
Acrylic and Ceramic. Your idea is less
work than mine were. I like it Congrats!


AnthonyPT
 

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postalrat said:
Speakers look great. What did you use to make such a clean rebate around speaker. The bowl shape looks like it would have been hard to deal with.


Thanks, I used a lathe. There is a special adapter for a lathe chuck that holds bowls on the outside rim so you can finish off the bottom. So I used a holesaw to cut most of the opening for the speaker and then turned it down to the diameter of the speaker. Once I had the opening I used a flat chisel on the lathe to create the rebate. Trial and error until everything fit right.

John
 
AnthonyPT said:
Hi Kazoo

You have just done what I have been
thinking of for X years Very nice
and I am sure the Bamboo units work
well. I use counterweights in a foam
core for balance as I used non Neo
Tang Band drivers. Have seen similar
sorts of bowls in Ikea. Picture is
of my sphere experiments in Paulownia,
Acrylic and Ceramic. Your idea is less
work than mine were. I like it Congrats!


AnthonyPT


Those are beautiful! Those materials would be a lot harder to work with. So how do they sound, especially the ceramic ones? Is there a ring to them or are they dead quiet? It would be a fun experiment to compare all those and wooden ones also with the same drivers to see how the sound differs.

John
 

AnthonyPT

Member
2004-10-29 9:23 am
Hi
The ceramic Spheres had weighted foam cores
and were lined with tar based spray plus rock wool
to deaden them. The blue sphere is made
of Stoneware and takes a long time to drill
holes in.The driver in the Blue sphere is
an Axon/Haes 4SF-01 with a fibre glass cone
Nylon bolts were used with a blu-tak putty
to secure it to the sphere. Till others
dropped them and I had to make more they
sounded very nice especially with a 6th order
bandpass sub I made. Imaging was very nice.
Did not have my Clio system to measure them then!
I am making some new ones at present. The 3inch
drivers I used are TB 517s & 319s also a Response
3 in coated paper driver from Jaycar which I
always liked. Most are in Acrylic spheres.

regards

AnthonyPT
 
Got to tell you these little 3" TB are impressing me. They sound smooth and are a pleasure to listen to. I hooked them up on my HT receiver and had the sub fill in the bottom. This was in a larger room and the room was filled with sound with authority. I was running around working on the house and every once in a while stopped and lost the concept of time just listening to these things. Next step I will be making more for a HT setup.

John
 
This thread has got me thinking. The web abounds with appropriate wooden bowls. I found some large ones (11-13"diameter) listed at Target and Ikea for about $20 each, and there is a truly monstrous ~16" diameter wooden salad bowl floating around at several web sites. At about $60 the really big one isn't cheap, but when you figure that a 0.5 cubic foot finished enclosure is about $100, two of these bowls is not too far off the mark for an enclosure volume that is similar or a bit larger. I did some preminary studies using the Tang Band 4" full range polypropylene driver (W4-1052 SD) and got some nice smooth curves with an enclosure volume of 0.5 cubic feet and a 2" diameter 4" long port. Pairing one of these drivers with a small dome tweeter for HF augmentation might be very nice indeed, and not too expensive.
 
Well, I've done it this time. I ended up nabbing a pair of Tang Band W4-654SE drivers. Not as magical as the bamboos, but a lot cheaper. Soimulations for a ported box are really smooth. Target sells a black rubberwood salad bowl with a flat bottom that looks like there will be room for the speaker and maybe a teensy dome tweeter to help out the high end. Guess I'm going bowl shopping soon....
 
Thanks, but to let you know the build was not that bad. If you have a lathe then it makes it easier. But once you start going bigger most affordable lathes are only a 12" swing. So probably the biggest bowl you can put on there would be a 11" or so. Unless the lathe head swivels than you are limited only by the clamp that holds the work.
I was also thinking how to do it with a router and a circle jig. I was going to make a clamp/ jig to hold the bowl. A square piece of plywood on the bottom, 4 threaded rods one in each corner, and then two pieces of plywood on the top. Using a circle jig with the router the lower top piece would have a hole cut out that was larger than the bottom of the bowl so it could center it. The top piece of plywood would have a hole cut out that would be the correct size for the driver mounting and then one more piece of plywood that would be the correct size for the rebate. The router would have a bushing that would follow the hole cutouts and the bit would cut the bowl. It would just take some measuring to figure out the correct hole sizes with respect to the bushing and router bit diameter. That should do the trick.

John
 
speed3 said:
You could easily use a hole saw for the driver. I did that for my 3" Tang Bands and it worked like a charm.

The bigger question for me is how you made the circular spacer. Care to share?


A hole saw??? That is too easy. I guess you can use one of those also. Then use a router bit with one of those bearing kits so you can adjust the amount of material removed for the rebate or you can forget the rebate all together.

The circular spacer was made with a circle jig and a router. I have the Jasper JIG and it works nicely because the holes are in 1/16" increments. All I did was cut the outside of the donut a little bigger than the bowl diameter. The inside I tried to cut as close to the inside diameter as possible. Once I glued everything together I chucked the whole enclosure into the lathe and used a chisel to round it down to the shape of the bowls. A little sanding and that's it.

John
 
That's right, I used a router with bearing for the rebate. Yes, a hole saw is very easy, which is another great thing about these small diameter full rangers. I figured I could make the spacer with my circle jig, but to get it precisely to the same diameter would be tricky. Your lathe idea works well, but I don't have one. Maybe I can track one down somewhere areound here.

Thanks
 

Arc

Member
2005-09-01 1:25 am
If there is a Harbor Freight around you they have a lathe that I 'believe' is 6"x12" for $89. They also have one that is 12"x24/26" something close for $149.

They might not be the best quality but they will for fine for making the spacers.

When I get home from school I am going to attempt to mimic your design. Thank you for sharing with us. I will be using the 871s.

EDIT: It's better!! 12" x 40" with a 6" sanding disk. $84.00

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45276