SLA Pro

[bzb]

I've completed the pair and they're already booked for 3 gigs this summer. First wedding gig is May 14th.

This first picture has the one on the left with the grill foam. The one on the right isn't 100% finished in this picture, but it's intended to show that they really don't look too bad in white without the grill foam. The grill needs one more coat of paint and it'll be mounted.


slapro1 by bzbatl, on Flickr

Got some bags made by Connie. Quick turnaround, cost about $60. connietookie23@aol.com


slapro2 by bzbatl, on Flickr

Video review will be posted when I've got some time to take em to an indoor venue and compare them to other cabs.


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Yep, couldn't wait.

Ripped all 8 panels from Arauco. Was going to do the baffle in BB, but I'm out of panels long enough... and I'm too impatient to wait until tomorrow night to start

Laid out the centers for the drivers. Used a hole saw for the tweets.



Setup for the woofers. Using a Craftsman circle cutter, same setup as the holes for the T39 mouth braces.



However, this was taking way too long on my POS drill press, so the plan is to use some 1/4" Luan I have laying around for a template, and cut the first hole on it. Then I'll use the router to make me a nice 1/2" template. I'll then use double sided masking tape and a flush cut bit to make the driver holes.

[bzb]

Baffle all cut.



Side port/handle setup with double-sided masking tape. Holds pretty well as long as you don't handle the router like an ape.



First glue up. Love the W jigs!



Going to glue up the braces after this first panel dries, then I'll actually be patient and wait for drivers to make sure they fit before I glue up the baffle.

[ewetho]

GO GO GO!!!

[Chris_Allen]

Ever considered modifying some of your braces so that you can keep a square edge as well as bracing?

[Bruce Weldy]

Ever considered modifying some of your braces so that you can keep a square edge as well as bracing?

Wouldn't be hard. Just tack on a 3 to 4 inch long strip of 1/4" ply on the two edges that overhangs by 1/4". That way it can do the job and still sit flat.

Downside is that you could only use those braces at the ends. I use 'em all over the place. Lining up the ends has always been way less troublesome that keeping the panels square. But building a set with the "wings" on 'em wouldn't be a bad thing.

[bzb]

Ever considered modifying some of your braces so that you can keep a square edge as well as bracing?

Wouldn't be hard. Just tack on a 3 to 4 inch long strip of 1/4" ply on the two edges that overhangs by 1/4". That way it can do the job and still sit flat.

Downside is that you could only use those braces at the ends. I use 'em all over the place. Lining up the ends has always been way less troublesome that keeping the panels square. But building a set with the "wings" on 'em wouldn't be a bad thing.

Agreed - I have a jigs that have the edge guides, but they're for... edges

I will be temporarily tacking a guide board for the baffle (or possibly just installing the top first), because it is insanely light and will slide around on the PL bead. Most of the time the edge panels are heavy enough that they'll stay put once you squeeze them down.

[Radian]

I don't have plans in possession, yet.

Is there any bracing to connect the baffle to the rear of the cab that would run the length in between the driver and piezo cutouts? That baffle looks like Swiss Emmentaler, and although the metal driver baskets would partially recover some of the structure, I seriously doubt the ABS piezo housings will be doing anything to handle stresses along that whole edge.

[Bill Fitzmaurice]

I don't have plans in possession, yet.

Is there any bracing to connect the baffle to the rear of the cab that would run the length in between the driver and piezo cutouts?

No. When the drivers are screwed and caulked in place the baffle is stiff enough without a brace, though you could add one if you wish. A stiffener or two connecting the baffle to the main brace would suffice, and would be a good idea if you go with 3/8" BB for the cab.

[bzb]

I might drop a single one in between the drivers. The Arauco feels like balsa wood, it's so light.

Everything dry fit. I like these small cabs. They're easy to get square

[bzb]

Bill, is the chart for the SLA Pro with or without the crossover on the piezos?

[ewetho]

Hey Bill,

Also what is an easy way (I HOPE) to get a measurement graph like you provide if I wanted to test the one I built?

Tom

[bzb]

Got my FedEx tracking number already... they might burst into flames waiting.



Would it make any difference/sense to flip one? So they're basically mirror images of each other when they're on sticks...

I'm covering the grills, so you won't be able to tell the difference from the front.

[Bill Fitzmaurice]

Bill, is the chart for the SLA Pro with or without the crossover on the piezos?

With. It's very much a necessity, otherwise there's a lot of bandwidth overlap between the woofers and tweeters.

[Bill Fitzmaurice]

Hey Bill,

Also what is an easy way (I HOPE) to get a measurement graph like you provide if I wanted to test the one I built?

Tom

You need measuring software, hardware and a lot of experience. True half-space measurements require splicing a ground plane and free-space measurement at the baffle step frequency.

[Radian]

No. When the drivers are screwed and caulked in place the baffle is stiff enough without a brace, though you could add one if you wish. A stiffener or two connecting the baffle to the main brace would suffice, and would be a good idea if you go with 3/8" BB for the cab.

Just for a visual of what I was talking about. The displacement values are bogus because I ran the plot using steel (wood isn't available in my sim) and the dimensions were completely eye-balled, but the distribution of the resultant displacement still comes through nicely. Red is the area of greatest deflection along the Z axis using a pressure applied across the entire face of the baffle.