Tarkus Build... Finally!

[hoosiercheetah]

Re: Let the gluing begin!

it looks like a little of that may have happened.

Ya, I see where you're seeing that. When I get to the shop this morning I'll take a look at that corner. Am I hearing you rightly that, if I have an under-glued spot, I can correct it by stuffing it with bondo?

And thanks for the gluing tip, I'll try it out!

[badman]

Re: Let the gluing begin!

Ya, I see where you're seeing that. When I get to the shop this morning I'll take a look at that corner. Am I hearing you rightly that, if I have an under-glued spot, I can correct it by stuffing it with bondo?

And thanks for the gluing tip, I'll try it out!

Exactly right, you can fill it in with wood putty or bondo. You can even make your own wood putty from your sawdust and wood glue, instead, cheaper and easier.

[hoosiercheetah]

Re: Let the gluing begin!

Assembly progresses slowly. Sadly, this is a spare-time project, and I don't have a lot of spare time. But, it is going a little faster now that I've bought more clamps!



I'm gluing up the sides, top and bottom first with battens. Then the baffle will go on. Then I'm framing the back with battens to make a flange, to which I will apply speaker gasket, so that I can have a removable back. This will allow me to use screws and nuts for the speakers instead of fiddling with Tnuts or hurricane nuts.

That's about it for now. I think I'm about three or four weeks from being done at my current pace.

[hoosiercheetah]

I don't have any clamps long enough to clamp the baffles on the woofer boxes. But I do have a big nasty pair of KLH speakers. Some day I'm going to Econowave them, but for the time being, they make excellent paperweights!

In other news, yesterday I finally had enough mdf glued together that I could test-run the crossovers and drivers. I set the boxes on their backs so I didn't have to mar the drivers' finish with hardware (PE is extremely explicit about this in their return policy). So, in incomplete cabinets, with no bracing or stuffing, powered by my little Lepai 2020, at half volume, these speakers are already louder and clearer that anything I've ever heard. I'm getting very, very excited to be done.

What I have left to do to the cabs:

Trim up the removable back plates for the woofer boxes, Get them fitted and sealed.
Cut in the 4" PVC ports.
Cut and glue on the hardboard for flushing the tweeters. Thank goodness I have plenty of that; I'm nearly certain I'm going to ruin one figuring out how to work with hardboard.
Install bracing in the cabs.
Install fiberglass in the cabs. Planning on using a roll of Kraft-faced R13 from the box store, I think I can glue the paper to the mdf and that should hold it in place, right? Any other thoughts on that?
Install drivers.
Rock On.

[rickyj]

Re: Tarkus Build... Finally!

Cool, using speakers to build speakers

[bolland83]

Re: Tarkus Build... Finally!

Welcome to the Tarkus club! I dig the crossover pyramids, any plans to put LED lights in them? Maybe a cool blue or red LED in each one so you can also use them as accent lights.

[hoosiercheetah]

Re: Tarkus Build... Finally!

Welcome to the Tarkus club! I dig the crossover pyramids, any plans to put LED lights in them? Maybe a cool blue or red LED in each one so you can also use them as accent lights.

Thank you! Yes, one of the first things I thought about when I had the pyramids together was lighting them up. I've done a little preliminary research, but like everything it's more complex than one would think. OR I might just cannibalize a string of Christmas lights and call it good. ;-)

By the by, I think the sunburst finish you did on yours is spectacular! I seriously considered ripping it off, but it wouldn't go with the crossovers. So I have something a bit more shiny in mind involving tin foil and lots of aluminum tape. :-D

[hoosiercheetah]

Flush mounting with Hardboard! I measured the tweet's flange at 3/16", and bought 3/16" hardboard. Which is slightly less than 3/16". I'm confident that the difference will be made up by the finish I'm going to apply to the board.

I cut the board with my trusty jigsaw and a "scroll/fine cut" blade, and it worked beautifully. I was afraid it would chew the board up but it really didn't at all. The marring on the face of the board in the pics is from my own carelessness at another stage of this process. Available time will determine weather I live with the defect (which will likely not show under the finish) or make a new piece.

Anyone have any thoughts on gluing the board to the mdf? Wood glue work ok, or is there something better?

[JimHRB]

Re: Tarkus Build... Finally!

I don't think wood glue would work very well to bond the hardboard to the MDF. I would use epoxy with some filler added to increase the viscosity, but that may be a bit pricey. Gorilla Glue might work, but I don't have much experience using that stuff.

[bolland83]

Re: Tarkus Build... Finally!

Construction adhesive (liquid nails) works pretty well with hardboard.

[hoosiercheetah]

Re: Tarkus Build... Finally!

I went with wood glue for the hardboard. I've been using Titebond 2 for everything else, and it seems to be holding the hardboard quite well!

I think I'm in the home stretch. Just a little more fitting together of parts to do. Today I'm going to go pick up the PVC for the ports, and I should be able to get them in this afternoon. If all goes well, I might actually be done with the rough build today, and have only cosmetics left to mess with.

And at this point, I might not bother with the cosmetics.

Here's a pic of an MT all put together, with the crossover in position!



So, today's question for the peanut gallery - what's the best material to use for stuffing (that I can get from JoAnn's) And, how much stuffing do the Tarkus boxes like? I remember Paul mentioning that he used egg-crate foam in his, and it seems like I've heard of people using quilt batting instead of loose polyfill.

I look forward to hearing everyone's opinion!

[Chris Roemer]

Re: Tarkus Build... Finally!

Most typically sealed boxes get stuffed w/polyfill or fiberglass. Vented boxes should be lined with convoluted (egg-carton) foam. The air in a vented box must be free to resonate, that's how they work. A Wal*mart mattress topper is a good, cheap solution. An alternative would be some other type of "open cell" foam (that means you can breathe through it, and/or it will hold water).

[hoosiercheetah]

Fin!

They're done!

Well, the rough build is done. I have a feeling they'll stay that way for a while. I have some definite plans for finishing, but I don't have much free time, and I do have other honey-dos in progress.

Photographic Evidence:



Ports going in. BIG ports.



Ta-Da!

I ended up using polyfill from EvilMart for the MT cabs. Three dollars for a giant bag of the stuff, so now I have polyfill for my next several projects, too. EvilMart also had big rolls of open-cell foam for pretty cheap - it's not convoluted, but I think it will still serve the purpose, if I understand the purpose correctly.

And since I have removable backs on the boxes, I can always change it later, and see if it makes any difference.

I haven't had a chance to really crank them up yet, but at the somewhat high end of reasonable listening volume, they sound fantastically amazing!
They far and away out-preform the rest of my system, and they play anything beautifully, rock, showtunes, whatever. My favorite moment so far: my daughter was watching the old SpiderMan cartoon this morning, and almost jumped off the couch when the first explosion went off. :D

That's all I have to say about that!