T48 impressions

[Tom Smit]

I finished my 24" wide 3015LF powered T48's just before new year...



if anyone wants to see any more build shots, let me know.

Ben

Nice lookin' cabs!!

And of course, more pics!!

[J_Dunavin]

LOVE the bracing!

[Harley]

I just love those braces

That cross brace creates such an optical illusion.

[anomalous]

Nice lookin' cabs!!
And of course, more pics!!

Thanks

Here are a few more build pics, starting with the pile of cut panels:





Some interesting chocks, guides, clamps and weights used to hold things in place...



here is the inside of the 'false bottom, before the bottom reflector is glued in place. the blocks are where the wheels mount through.



test fitting the 3015lf:



and for anyone interested in CAD, here is a snapshot of the model I did in Solidworks before I started:

[88h88]

I love that colour. Those are some very very well made subs. The bracing hurts my head to look at though

[Robin_Larsson]

Reeeally nice cabs! The bracing is just wicked
We were thinking about doing something like that with our T48s, but ended up just making holes in the standing braces. But now that I see how fantastic it looks with the curved braces, I think I´ll have to do something like that on my next two, and change the 2 "old" ones

Nice Solidworks model! Did you cnc-route the parts? I did a 2D cad of mine in Autocad, and cutted the plywood with the abrasive waterjet at work But that was before the changes for the Labs and such. I have 2 more 3015LFs waiting to be used, so I dont know if I´m gonna make an updated cad model or not.

Btw, when you made your Solidworks model, did you import the Sketchup model, or did you draw it from scratch, using the models measurements, or the plans? I did the later, I tried to export the Sketchup model to Autocad, didnt turn out great, but I could get the sides good atleast. But by then I had already drawn everything else, completly ready, from the measurements in the plans, and of course the plans are rounded of a bit, but for some stupid reason I went by those measurements instead of the Sketchup model, the biggest difference I could find was like 2mm in lower hornfold So, it doesnt matter of course, but still irritating

I measured the angles in the hornpath, and the angle in the third part of the horn is smaller than in the second part, in my drawings its actually 0.7degrees difference, or almost the same angle in the the third part as it is in the first. Is that how it should be?
It strikes me as a bit odd, I would have thought that the path would expand all the way, in an almost exponential way?
But I dont know ofcourse, it just looked odd, I´m not questioning Bill or anything But maybe I did something wrong in my drawings? But as far as I know, thay are exactly as in the plan, down to a 1/100 of a millimeter in cad ofcourse, the actual speakers have larger tolerances

Sorry for the hijack, atleast it had something to do with Cad

[LelandCrooks]

I am so stealing that brace. Awesome.

[camrynekai]

Very nice!!!

[wounded horse]

Those T48s will look wonderful v plated. My vote for the best design mod I've seen on the forum. And they look so right in that colour.

[wounded horse]

Those cabs look like mahogany. What ply is that?

[Bill Fitzmaurice]

Those cabs look like mahogany. What ply is that?

Lauan, or a close relative.

[Greg Plouvier]

Great look!

[anomalous]

Nice Solidworks model! Did you cnc-route the parts?

no, not for the T48. its too simple a design to be worth the effort - the way i built these was to make the width of the cabs = depth - (2*12mm), so that all the panels (except the bracing) are exactly the same width. When I picked up the plywood, I had the supplier rip it into strips of the correct width (608mm, from memory) on his expensive, accurate table saw. then i just cut all the panels to length by hand using the sled/jig I made up. super quick and about as accurate as you can get without investing big $ in a table saw and a workshop to fit it in.

I built a laser cut DR200 a while back, as a proof of concept, and my next project is going to be to redraw the DR200 in solidworks with a mind to building a small herd. Not sure if I'll go lasercut, or abrasive waterjet. the waterjet is more expensive, but it might be possible to cut more than one sheet at a time with it. In your experience with your waterjet, does the cut flare much towards the bottom of thicker materials?

Btw, when you made your Solidworks model, did you import the Sketchup model, or did you draw it from scratch, using the models measurements, or the plans?

I drew it from scratch. many reasons - one being that Ive found the sketchup models are not super accurate - in some places the panels dont meet properly, or overlap, or the geometry isnt quite right. sketchup is a great tool for mocking up ideas, but is no substitute for a proper, rigorous cad package. I also find that drawing the models from scratch helps me understand them, and often I come up with ideas or optimisations along the way (for example the parabolic curves on the bracing that everyone likes so much). redrawing the models from scratch also allows me to make changes to accomodate different material thicknesses (in this case, 12mm ply instead of 1/2" ply). also makes it easy to scale the model. I havent done it yet, but It looks to me like the T48 is a more or less exact scale-up of the T39. which means that it should be possible to scale UP the T48. Probably a silly idea - the T48 is a sweet-spot in terms of max efficiency of plywood use - but I do wonder what the response of a Titan-Sixty-Something would be like. What would a Titan of sufficient size to accomodate an Eminence Kilomax Pro 18" be like? I really dont know...
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[anomalous]

I am so stealing that brace. Awesome.

Go for it! if people like, I'm happy to post PDF's of the templates I used. I can redraw them slightly for 1/2" ply to perfectly match the plans. (mine are slightly different, being cut for a version modified to use 12mm ply)

[anomalous]

Those cabs look like mahogany. What ply is that?

Lauan, or a close relative.

they are an unspecified exterior hardwood "PLYWOOD HARDWOOD EXTERIOR - BC - S2S - IMPORTED - A BOND"

Could be Lauan. The unspecified nature of it makes me a bit uneasy (I really dont want to be using rainforest timber) but the T48's needed something with a sheet size of 1220x2440, and this was the only locally available product I could find in those dimensions. To be honest, I'd rather just use plantation pine. this hardwood ply tends to splinter when drilled or cut into, which can make a bit of a mess if you arent careful. to get a clean cut with a hole-saw or spade bit, you need to make sure there is always a backing board clamped in place. your drill bits need to be razor sharp, as do your sawblades.