4T speaker build, Rebooted

[Solid7]

I used heavy duty cargo straps that you can buy all over to clam the sides. You may have to make a piece of wood that has the same curve profile as your enclosure to put between the strap and the side to evenly distribute the force.

+1

You know, I forgot about those. But that's also a really great way to do it. It also helps to make a rounded "end piece" to fair the strap, and properly distribute the force, but it's definitely a good way to go.

[BigguyZ]

I used 4 straps wrapped around the speaker, with 4 cauls running length-wise. I still have some gaps between the cauls and at the ends...

[BigguyZ]

Well, I've had really good results with using cauls and screwing the caul to the side and having that clamp the speaker. I have one more layer on one side for the first speaker, then I'm good to start on the next one. I'm thinking I should be able to do a layer on each side at the same time, instead of only a ply at a time. the second speaker should go much more quickly.

I've been using the gorilla glue, as I mentioned. I think it's giving great results, even though it's definitely messy! I've managed to get glue everywhere- even with being careful. Having poly glue soak through your t shirt and glue your stomach to the shirt is NOt fun. I now where 3 shirts when gluing up.

I have pics, but I again need to get them off my phone first. I'll post them soon.

[looneybomber]

Having poly glue soak through your t shirt and glue your stomach to the shirt is NOt fun.

Now where's the pictures of that?

[BigguyZ]

Now where's the pictures of that?

TRUST ME- not a pretty sight! That really hurt! :M

Ok, here are the pics of the first speaker... it's getting there. Once the sides are done, it'll be time to clean up the squeeze out and trim the overhang. I'll use a flush trim bit on the top/ bottom, but I'll use a flush trim multi-tool blade to cut the curved sides. I plan on rounding over the front, but I'm still working out how I'll be doing that.

Using Gorilla glue is definitely expensive, so I hope that this turns out well. Each 32oz glue bottle costs $25, and I need about one per speaker side. So that's about $40 in HDF and $100 in glue! But I honestly think it'll provide better results than PVA, and after all this work why not spend the money and do the best you can?

Once it's all built, then it's just about saving up the $$ for the actual kit/ parts.

I was going to get everything completed first, including the veneering. But I think I'll just leave them raw at first. $500+ in veneer and supplies will be a hard sell until I can confirm that the speakers are correctly set up/ installed.

[Hdale85]

Mine didn't look much better if any at that point trust me!

[Solid7]

Using Gorilla glue is definitely expensive, so I hope that this turns out well. Each 32oz glue bottle costs $25, and I need about one per speaker side. So that's about $40 in HDF and $100 in glue! But I honestly think it'll provide better results than PVA, and after all this work why not spend the money and do the best you can?

Just curious why you think that Gorilla glue is the best?

I hate the stuff, and have always found that Elmer's Wood glue to be (obviously) cheaper, easier to work with, and more than sufficient to hold for your material of choice.

You have a good start, but it might be easier for you to think about a different adhesive. Also, if you leave screws in under your veneer, you should have no worries whatsoever.

Not trying to criticize - just hate to see you suffering needlessly!

[BigguyZ]

Just curious why you think that Gorilla glue is the best?

I hate the stuff, and have always found that Elmer's Wood glue to be (obviously) cheaper, easier to work with, and more than sufficient to hold for your material of choice.

You have a good start, but it might be easier for you to think about a different adhesive. Also, if you leave screws in under your veneer, you should have no worries whatsoever.

Not trying to criticize - just hate to see you suffering needlessly!

Suffering I am! But I don't think it's needlessly. I agree that PVA is MUCH cheaper and MUCH easier to clean (especially considering that you can't really clean poly glue). But, I really like the fact that the poly glue will expand and fill any gaps. That means that if there is a bend in the HDF that's not 100% conforming to the curve, it'll still be solid. And why not make sure that there's nothing that going to be an issue, considering how much time I'm putting into this either way?

Also, I find that it takes a day for the poly glue to cure fully, it's solid enough to add the next layer after an hour or so. So in that respect I like it better, as I wouldnt' feel comfortable unclamping the PVA-glued panel until at least 4-5 hours afterwards.

Trust me, I use TBII for 90% of my gluing needs, and rarely used poly/ gorilla glue. But in this case I think it's worth that bit of insurance to use it.

I'll be heading over to my shop this evening I hope, so I'll have the last layer on the first speaker, and I plan to start the next one!

[Hdale85]

I used Titebond II for my cabinets.

[BigguyZ]

Not quite as close as I thought!

So, I realized something very important today. The front of my template for my braces was 6.5" accross. With the two 3/4" sides, that's a total of 8" accross- the correct width of the baffle. HOWEVER..... Since this is a cuved side, and there's two layers of 3/4" MDF for the baffle, and the angle of the side wall is narrowing towards the front... the actual front will only be about 7" wide as it's planned now! :evil: :M :M :evil: (roughly- I'll take more accurate measurements, but you get the drift).

So what's the solution? Well, I'll have to add another 3-4 layers of HDF per side.... That does increase the costs- but mostly due to the glue (if I stick with gorilla glue). It'll also increase the time until I'm done. The only good thing- it should increase the weight and mass of the walls. That's 10 layers of 1/8" HDF, or 1.25"! That's pretty thick. Luckily, I'm a pretty big guy, so moving them probably won't take two people (then again, once the drivers are in....).

You try to do something different from the standard, and it bites you in the rear...

[Solid7]

So, I realized something very important today. The front of my template for my braces was 6.5" accross. With the two 3/4" sides, that's a total of 8" accross- the correct width of the baffle. HOWEVER..... Since this is a cuved side, and there's two layers of 3/4" MDF for the baffle, and the angle of the side wall is narrowing towards the front... the actual front will only be about 7" wide as it's planned now!

So if your baffle is narrow at the front - did you make a mistake in calculation somewhere that may also affect the internal volume? Or did you keep internal volume while unintentionally neglecting baffle width?

[BigguyZ]

No. Internal volume is still good. It's just the width difference at the point the baffle begins versus the point the baffle ends.

[BigguyZ]

I have just two more layers to do on one side of the first speaker, then I'm done. I think I overshot with the number of layers, but Jed noted in the other Dynamic thread that up to 1" greater thickness is fine. Also, I'll be using as big a roundover bit as I can on these, which should help as well. I think the one I have is 1-1/8".

I'm rethinking what glue I should use. I still have glue on my arms from handling the speaker, and at $25 for a 32 oz bottle that lasts 3-4 layers, that's about $75 per side per speaker in glue alone. Now, I think think it's the best solution, and for as much work as I'm putting into it, it's not that much more- especially considering the project's full cost and that I've already spent $150 in MDF that I didn't use for the stacked lam version. So I'll probably continue with how I'm going. Good news is, I've found that I can reliably do two layers at a time. So, it's the initial layer for the next speaker, then 4 more applications of two sheets for both sides. That means only 5 more glue-ups and then it's cleanup time with a chisel and scraper.

I'll be stalled on progress for a bit though, as I have an apartment to finish for new renters on 10/1. And currently there's no kitchen and the floors are a mess!

BTW- with as much HDF as I have, these things are heavy. I'll have to put them on a scale to see exactly what they weigh in at, but I'd guess 45-55 lbs without the drivers.

[Solid7]

BTW- with as much HDF as I have, these things are heavy. I'll have to put them on a scale to see exactly what they weigh in at, but I'd guess 45-55 lbs without the drivers.

I have designed custom enclosures, and am in the process of building the 2T and 2CC. My designs are about 135 lbs. each. :B

[BigguyZ]

Just a note- I've been in the process of moving my chop from my basement to the garage for my new house. I've stalled a bit with winter and some flooding due to the thaw, but I expect soon that I'll be working on the speakers in the next week or two. So right now I'm looking at using vacum to clamp the sides. That might be more difficult to set up, but it'll give more consistent pressure. I then would feel better about using PVA glue rather than Gorilla glue...

I'll update with pics once I pick this up again.

Oh, and I bought some excellent waterfall bubinga to wrap these in as well. I can't wait to get these finished.

[BigguyZ]

I just ordered my vacuum press and a bag. Also, I decided that plastic resin glue bonded in the vacuum bag would be the best option for glue. Poly glue is just too much mess and too $$. I like the idea that it'll get into any minor voids if the clamping pressure isn't 100% even, but with vacuum pressing the pressure will be 100% even.

So for $100 shipped, I got 25lbs of the glue. That'll be enough to finish the speakers, and do quite a few other woodworking projects I'd like to do.