Rounded Edges

Guitar cabs both you and your audience can hear better.
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sloaneamps
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Rounded Edges

#1 Post by sloaneamps » Sun Aug 01, 2021 9:03 pm

Hi,

I’m wondering if any who have built the XF cabs have used a 1/2” round over router bit for the edges. I build guitar heads and use 3/4” wood with a 1/2” round over on my cabs. This way I can use the 1/2” metal corners. I’m looking to do the same on the XF cabs but using 1/2” wood with brad nails or screws looks like I’ll probably end up having the router bit hit the nails or screws. I was thinking of using 3/4” braces on the inside corners along with the PL glue so the nails or screws can fasten to the braces which would give enough clearance for the 1/2” round over bit. Would the braces be ok and not effect the sound?

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Bill Fitzmaurice
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Re: Rounded Edges

#2 Post by Bill Fitzmaurice » Sun Aug 01, 2021 9:18 pm

The standard round over is 3/8". Using soft steel brads you can route right through them, and if you set the gun for a deep drive you may not hit them at all. Battens on the corners are old school. They don't make the joint any stronger, they just add unnecessary weight and complexity to the build.

sloaneamps
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Re: Rounded Edges

#3 Post by sloaneamps » Sun Aug 01, 2021 9:53 pm

Thanks. I was also thinking i would be able to route through them since I have decent carbide tip bits. If I do that then it probably wouldn’t matter if I used 3/8 or 1/2 inch. So no need for the battens. But I’m pretty sure my metal amp corners are made for 1/2 round over but it’s possible the the corners I have will work with 3/8 too

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Bill Fitzmaurice
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Re: Rounded Edges

#4 Post by Bill Fitzmaurice » Sun Aug 01, 2021 10:23 pm

1/2" may be used with metal corners. I only use plastic, for their interlocking ability, and those I've used are 3/8".

Bruce Weldy
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Re: Rounded Edges

#5 Post by Bruce Weldy » Mon Aug 02, 2021 9:48 am

For what it's worth, I used the 3/8 roundover on my XF210 with no corners at all. Corners are a little tough to get looking right with the angled front.
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6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

Bruce Weldy
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Re: Rounded Edges

#6 Post by Bruce Weldy » Mon Aug 02, 2021 9:49 am

Oh, I did use corners on the bottom, just not on the top.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

sloaneamps
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Re: Rounded Edges

#7 Post by sloaneamps » Mon Aug 02, 2021 11:04 am

Thanks for reminding me that I will have to take the slant into consideration. I think 3/8 and 1/2 both look good but the metal corners that I use on my amp heads probably fit nicer on 1/2 round over. I also tolex the cabs so those corners hide the potential faults in my tolexing :D I think I need to do some experimenting with scrap wood

himhimself
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Re: Rounded Edges

#8 Post by himhimself » Mon Aug 02, 2021 5:22 pm

I used 3/8" roundover on both my T30s (1/2" BB, plastic stacking corners), as well as my Otop jarrays (1/4"BB, no corners due to the angles). I did use battens on the inside of the otops, just to give some bonus meat to the thin 1/4" sides when rounding over. Super strong, no issues.
2xT30 (20", 3012LF)
2xT30 (21", 3012LF)
4xOtop J-array (Beta12, melded/straight piezos)
Truck Tuba (MCM)
Next up: 2xJack12 or family of table tubas

sloaneamps
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Re: Rounded Edges

#9 Post by sloaneamps » Tue Aug 03, 2021 12:07 pm

It turns out the metal corners I have fit better with 3/8" round over than the 1/2". Next question If I need to start a new thread I apologize and will move it. Can I make the box rectangular instead of slanted like the rectangular XF412?

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Bill Fitzmaurice
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Re: Rounded Edges

#10 Post by Bill Fitzmaurice » Tue Aug 03, 2021 12:13 pm

You can make the exterior rectangular, but the baffle back tilt angle must be maintained, just as it is in the 412. I advise against it, unless it's for the bottom cab in a stack.

sloaneamps
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Re: Rounded Edges

#11 Post by sloaneamps » Tue Aug 03, 2021 3:32 pm

Just curious as to why you advised against it is it due to the extra weight?

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Re: Rounded Edges

#12 Post by Grant Bunter » Tue Aug 03, 2021 4:04 pm

sloaneamps wrote:
Tue Aug 03, 2021 3:32 pm
Just curious as to why you advised against it is it due to the extra weight?
I'll take a punt.
The XF design is about not aiming the cab output at the guitarists knees.
That is the traditional approach, to aim at the knees. But the guitarist can rarely hear the cab that way.
The solution then becomes to turn up.
Then the rest of the band do the same.
All of a sudden, stage volume is painful.

Using the angled baffle makes it easier for the guitarists to hear the cab.
It wouldn't surprise me, with a cab like this, to do exactly the opposite of what they used to do.
And turn down, because "fark that's loud".

The tendency, in a rectangular style cab, will be to build it "traditionally" with a flat baffle, and that's not the design...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

sloaneamps
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Re: Rounded Edges

#13 Post by sloaneamps » Tue Aug 03, 2021 4:16 pm

Yes I understand that purpose of the angled baffle and that should not be changed as Bill said. The question was if the cab cab can be rectangular, but still keep the correct angle on thr baffle.

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Re: Rounded Edges

#14 Post by Grant Bunter » Tue Aug 03, 2021 4:34 pm

sloaneamps wrote:
Tue Aug 03, 2021 4:16 pm
Yes I understand that purpose of the angled baffle and that should not be changed as Bill said. The question was if the cab cab can be rectangular, but still keep the correct angle on thr baffle.
All good.
An angled baffle in a rectangular cab will alter horizontal and vertical dispersion as well...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Bill Fitzmaurice
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Re: Rounded Edges

#15 Post by Bill Fitzmaurice » Tue Aug 03, 2021 4:51 pm

Making the cab exterior rectangular will shade the highs a bit if you're standing close to it, especially with a 210 or 212.

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