SLA Pro - Powered

[CarterKraft]

You might also be able to get it done with a 3" router bit too.

This might be a simpler solution to a 3" long cutter. These are supposed to be really nice for using the router in a table to allow the bit to come high enough to be able to change the bit without having to remove it from the table.
https://www.amazon.com/Inch-Shank-Route ... 7527&psc=1

[Bruce Weldy]

You might also be able to get it done with a 3" router bit too.

This might be a simpler solution to a 3" long cutter. These are supposed to be really nice for using the router in a table to allow the bit to come high enough to be able to change the bit without having to remove it from the table.
https://www.amazon.com/Inch-Shank-Route ... 7527&psc=1

That's a good suggestion.

But, for this deal, I'm going with the screw-in mount.....won't have to do all the cutting that way.

[Seth]

Was thinking a bit about your build and intentions and came up with a few possible modifications you may consider.

If you moved the subs passive crossover from the T24 and put it in the SLA Pro, you wouldn't have to run two cables to the sub and it would open the possibility of also using the SLAP to power a T39. You could have two saved EQ profiles for each sub, depending on your needs.

Just a thought inspired by the amount of EQ you'll need to get the 50Hz region high enough to balance the sound out. Your T39 will eat up about 10dB less of usable power, allowing the SLAP to run 10dB hotter too, compared to running it with the T24 EQ'd to a similar response curve. Does that make sense in words? Makes sense in my mind.



Example, if you have 300watts of full range signal (which is roughly what I'd expect from that amp) and tune the output of the sub region 10dB hotter than the mids and highs, the SLAP will get limited to roughly 30w with the T39 and only 3watts when used with the T24 tuned to the same curve... I think??? Doesn't seem right, but I'm pretty sure the math is right.

In any case, having the sub crossover in the SLAP would open the possibility to use it with a T39 as well... and eliminate the need for two cables to/from the sub. I'd have to give some thought on how to wire that up with the switch to work with your intentions though.

[Seth]

Example, if you have 300watts of full range signal (which is roughly what I'd expect from that amp) and tune the output of the sub region 10dB hotter than the mids and highs, the SLAP will get limited to roughly 30w with the T39 and only 3watts when used with the T24 tuned to the same curve... I think??? Doesn't seem right, but I'm pretty sure the math is right.

Just remembered that the T24 (BP102) limit is 35v... so limiting to that figure would put the power to the SLAP at 1.5w for a response curve with a 10dB hump on the bottom end, assuming you play content that utilizes 50-60Hz content and that you actually desire that much in the bottom end. A 6dB bottom tilt would give you about 4w to the SLAP with the T24 and 75w with the T39 if the content is at the limit in the 50-60Hz region.


Might be a good idea to put that other top hat in one of your T39's.

[Seth]

^
All of that doesn't take into account any boundary loading. Obviously, indoors, utilizing wall or corner loading would go a long way, in this instance, to getting more usable power to the SLAP.

[Bruce Weldy]

^
All of that doesn't take into account any boundary loading. Obviously, indoors, utilizing wall or corner loading would go a long way, in this instance, to getting more usable power to the SLAP.

Thanks for all the suggestions, but this build is really all about form factor. If I feel the need to drag my trailer with the T39s, then the OT12s are already in there. I barely am willing to hoist that T24 up into my truck, I danged sure ain't going to be toting that T39 in and out of that truck bed.....and my new truck is about 2 inches higher than my old one.....(ok, enough whining....)

Also, that crossover in the T24 has a really good sized coil....it would be a bit of a task to stick all of that inside the SLA. Anyway, I really like the way I have it configured right now. I can run it passive, full-range powered, or with a sub powered......I like the options. In fact - if I ever decide that the on-board amp doesn't have enough juice (I'm still not sure that it does), I can take an amp and driverack to power the mains and use the on-board amp to run a monitor....

[Seth]

^
All of that doesn't take into account any boundary loading. Obviously, indoors, utilizing wall or corner loading would go a long way, in this instance, to getting more usable power to the SLAP.

Thanks for all the suggestions, but this build is really all about form factor. If I feel the need to drag my trailer with the T39s, then the OT12s are already in there. I barely am willing to hoist that T24 up into my truck, I danged sure ain't going to be toting that T39 in and out of that truck bed.....and my new truck is about 2 inches higher than my old one.....(ok, enough whining....)

Also, that crossover in the T24 has a really good sized coil....it would be a bit of a task to stick all of that inside the SLA. Anyway, I really like the way I have it configured right now. I can run it passive, full-range powered, or with a sub powered......I like the options. In fact - if I ever decide that the on-board amp doesn't have enough juice (I'm still not sure that it does), I can take an amp and driverack to power the mains and use the on-board amp to run a monitor....

I hear ya. My mind was a little overactive today. LOL

Have you taken any pics of the back of the cab with the amp mounted?

[Bruce Weldy]

Have you taken any pics of the back of the cab with the amp mounted?

Not yet....on my list of things to do.......got tied up with a couple of other projects....slapping some paint and duratex on a rack case my bass player built and swapping out some tubes in an old Classic 30 with another friend.....so, fun stuff.

I plan on getting some good pics once I get the grill and get the SLA mounted on the sub.

[Bruce Weldy]

A few things have been going on since we last saw our hero valiantly trying to rescue victory from the jaws of defeat.....but, I digress.....

As per Seth's excellent suggestion, I ordered a screw-in mount and pole for the T24/SLA combo.

Drilling out a 1" deep hole down into the brace on the T24 was way easier than a much deeper one for a standard top hat would have been.

The forstner bit stayed in the hole cutout while taking out the brace - so, it was pretty danged easy.

Then a little squirt of caulk and some screws....

And Voila! The Bose Killer is born.....

Here's the back.....the speakon configuration was covered earlier, but it allows for the cab to run as a passive cab, powered as a full-range, or powered with the sub providing the crossover for the SLA.

[Bruce Weldy]

Time for many thanks to Radian.

He reached out and offered me a grill that he had littering up his shop. A little FedEx and a little PayPal later and the grill arrived in excellent shape - very nice packaging job, Tom!

The grill was a little long and a little wide.

First I needed to square up one end. So, I did what I've done in the past when cutting grill material that has worked very well....

I clamp the grill between two pieces of scrap BB (that has a straight edge of course). Then insert a fine tooth blade in my Bosch jigsaw (cuts like buttah). I use the edge of the scrap as my guide and just cut along the edge while everything is clamped up good and tight.

Before.....

After.....

Then had to get a longer piece of scrap for the vertical cut.....I cut both dimensions 1/8" short of the inside measurements of the cab.

After finishing the cuts and putting it in the opening, I noticed that it was going to be hard to align the hole properly on the piezo side because they are really close to the edge. So, I clamped it back up and took off an addition 1/16" or so to give me a little more wiggle room. I like the fit now.

It's always a bit of a struggle deciding how to attach grills - especially with so little room for the screws. No way to use small rubber feet as standoffs - so I came up with a different approach.

I found the thickest old guitar cable I had laying around and pulled out the interior cable and ground, leaving just the rubber jacket. Outside diameter is big enough to not go through the holes in the grill and inside diameter is big enough to accept the screws.

I was going to use pan head screws, but I only had some in 3/4" length and that just isn't quite long enough. I have a bunch of the cabinet screws that came with the OT and T39 kits from Leland years ago. Turns out that the bevel head fits perfectly in the grill holes, so that's what I'm going with. I cut the rubber jacket down to 5/8" lengths - that will be a good offset and still leave plenty of bite from the screws.

Last piece I needed to complete the build was some foam backer for the grill. In the past, I picked it up from Wal-Mart - it's just foam filters for window AC units.

However, Wal-Mart, Home Depot, and Lowe's all think that Air Conditioning is a seasonal thing ...... ya' gotta' be kiddin' me! We're in Texas!

So, after spending a morning driving all over town, I came home and ordered 3 of 'em from Amazon....which I should have done yesterday, because they would have been here today. In case anyone is wondering - it's the Frost King brand and it comes in 24x15 pieces....I'll have to do a little splicing, but I did that back with the WH10s years ago and it's invisible.

Anyway, hopefully that shows up soon and I can button it up. Then it will go outside for some EQ work.

Stay tuned....

[Bruce Weldy]

The foam backer came in, so I set about cutting it to size. Had to do a splice as it wasn't long enough at 24x15. Not a problem with this stuff. Made the cuts and used some blue tape to hold the pieces together.

Then sprayed the grill with adhesive (never the foam - don't want to clog it all up). Laid the grill on top of the foam, then a piece of scrap plywood to cover it all and some weight on top of that.

Went out this morning and decided where the screws would go. I used an old leather punch I had on the wall to cut holes in the foam through the grill holes. That way the foam won't catch and twist around the screws. Put the screws through the holes and then put the rubber stand-offs on the back. Laid it in place on the SLA (laying on its back), lined it up and screwed 'em in. Didn't even use pilot holes. Those cabinet screws are really sharp and start quite well on their own.

Came out pretty good.....

The Bose Killer is finished......a least the hardware part......next up, I'll have to get it outside and get the on-board EQ set.

I'll let you know how that comes out and get some better pics without my shop chaos in the background.

[himhimself]

Looks totally awesome, Bruce. I like the leather punch idea. Nothing more frustrating than having a screw wind up the fabric it's going though. I used a hot nail, heated up with a torch, to melt holes through the grill cloth on my truck tuba. Thanks for the foam info - I still need to back the grills on my j-arrays...

[Bruce Weldy]

Looks totally awesome, Bruce. I like the leather punch idea. Nothing more frustrating than having a screw wind up the fabric it's going though. I used a hot nail, heated up with a torch, to melt holes through the grill cloth on my truck tuba. Thanks for the foam info - I still need to back the grills on my j-arrays...

Well, here ya' go....

https://www.amazon.com/gp/product/B07YN ... UTF8&psc=1

If you can find 'em at Wal-Mart - the exact same thing is about $2 each. But, you might have to wait until summer for 'em to stock 'em again.

[Tom Smit]

Bruce, that's a killer set up you got there. I try being punny LOL. By the way, why ain't you on the front porch a'rockin'?

[Bruce Weldy]

Bruce, that's a killer set up you got there. I try being punny LOL. By the way, why ain't you on the front porch a'rockin'?

I don't know.....lazy?

And at my age, I'm not sure if you mean rockin'-out or rockin' in a rocking chair.....of course, I guess I could do both at the same time.