My $13 project

Today I started building my new surround sound speakers using TB W3 871s. I am building 10 sided cubes with free drivers (from a very nice person) and old wood from my last test boxes. The only thing I had to buy was binding posts, and they cost $13. I thought I might as well go all out on the binding posts, since I'm not spending any other money.

Dave (Planet10) suggested building aperiodic enclosures, so I thought I would try it out. Below is a picture of test fitting the pieces of wood. For the aperiodic vent I'm using fiberglass insulation and on either side of it are mesh gutter guards.

I was unable to make a lot of progress because my mom and I are remodeling our garage appartment ourselves. Because of the remodel we have lots of insulation. The gutter guards are old, so they were free also.

I wanted to know if I should line the interior of the cabinet with carpet padding, also free. I read that there should be a clear pathway from the back of the driver to the aperiodic vent, so I'm guessing I shouldn't use too much poly-fil.

If you go to my website there are more pictures of the progress so far.

Thanks,

Josh

Thanks a lot Dave for all the help and suggestions. I'm excited about this project, neither of my parents know how to even use a table saw, so figuring out all of the 45 degree cuts were difficult, when the ousides were odd lengths like the square root of 2 and another was the square root of 8.

Also how can I come up with a filter for these speakers, I've seen John's, but he says only use it with his boxes.

Thanks,

Josh

Yea, I saw the prototype boards when I was over there, they look nice, I'm sure I'll end up getting one.

Do you think I should just not worry about a filter right now?
Or should I try John's values?

Thanks,

Josh

Re: Re: My $13 project

jjdche said:

Cubes have 6 sides.

Click to expand...

not always, this cube (built by a diyaudio member) is 26 sided. I wanted to build something like that at first, then I decided not to. I thought my box would be even harder since it is sooo small, and I'm 17 and have no one to show me how to work a table saw well.

I wanted the exterior to be low diffraction, and the interior to be have less dips and peaks, I'm guessing I will only have like +- 3db, well I'm hoping. I'm also going to add some wood to the internal sides of the enclosure so they aren't flat and the box will be more of "the perfect box".

I'm slowly learning how to get to use my table saw. Cutting the 45degree cuts that were less than 1.5" on the long side were not going to be easy, but I managed to figure it out.

Thanks,

Josh

Thanks Dave, Its a good thing I didn't try to make an irregular rhombi-caduceus. I would hae never figured out all that math.

jaudio, they are all 45degree angles. I used my table saw (Ryobi BT3100). I was bored in AP statistics, so I spent the entire period coming up with the design and side size.

I did a lot more work today, but was unable to finish all of it. I managed to use way too much glue and it took a very long time to glue. Right now each "irregular octagonal prism" is missing the side with the aperiodic vent, and one large side.

The aperiodic vents were/are really hard to cut, because I tried to use my router on that tiny piece of wood and it would move all over, even when I clamped wood all around it so it wouldn't move.

I was wondering if I could spray paint the fiberglass insulation, or if there was anything else I could use. I have lots of poly-fil laying around. Would densely packed poly-fil create the same effect as fiberglass insulation?

Thanks,

Josh

Here is a picture of all the cuts I made yesterday

planet10 said:

if you had cut all the "side" cuts at 22.5, each piece would be the same where they joined.



Polyfill isn't as effective as fiberglass, so it would depend on the tuning you end up with. Don't paint the fiberglass, but there is no reason you can't add a piece of doubleknit to the sandwich.

dave

Click to expand...

Dave, What is doubleknit?

Thanks,

Josh

Thanks Dave, I'll look for some.

To Jason and Solinar,
My Mom's dad owned a hardware store and cut off his pinky. He came in town and gave me an hour lecture about what not todo. I have bought a push stick that works really well. I refuse to touch the wood if my hands are withing 3" from the plastic blade cover. My Mom also went over safety stuff with me right after I got it for my birthday.

What I'm a little more worried about is the router, my Mom had never seen one before i bought it. I had a friends dad (who can show me how to use a table saw but I haven't been there in a while) show me the gist of using a router. I've gotten good enough to do simeple things like make flushmounts, and roundovers, but unfortunately I haven't bought a guide (in fat can anyone recomend an online store to buy a clamping guide from?). What was so difficult about this project was the aperiodic vent is on a piece that has 45 degree cuts on both sides, and the outside (longer part of it) is only 2.8" (square root of 8) long, and 4" wide. For the aperiodic vent I'm doing a 1/16" flushmount for the mesh gutter guard. I actually did it somehow on one of the peices, but I'm having trouble with the other.

Does anyone have any suggestions?

Thanks,

Josh