retrofitting larger mouth

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Rich4349
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retrofitting larger mouth

#1 Post by Rich4349 »

Rich4349 wrote: Mon Nov 13, 2023 8:29 pm
Bill Fitzmaurice wrote: Mon Nov 13, 2023 4:22 pm If you need to go lower than V plated T48s will go build T60s.
Not lower than 40/45: louder at 40/45.
I had acquired some 24" wide T-48s with 3015LFs in them. If 36" wide versions give such smoother and louder response, why wouldn't adding a mouth flare to a 24" wide help? I'd much rather spend a couple days and $100 than weeks and $1,000.

2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!

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Bill Fitzmaurice
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Re: retrofitting larger mouth

#2 Post by Bill Fitzmaurice »

That's what V coupling does, without the need for adding anything other than the plate.

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Seth
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Re: retrofitting larger mouth

#3 Post by Seth »

@Rich
For the sake of conversation, I think I see where you're going with this, and I like it! If for nothing more than purely the opportunity to explore and learn.

I've had a similar thought, to add a hinged flap to the top of the cab that, when deployed with a matching/complimentary sized V-Coupler, would add another foot or so of horn length and also increase mouth area. It's on my list of things to test and videos to make. To me, it would be interesting, no matter the actual test results.

Going back to what you're talking about and adding to the thought soup; as it occurs to me, adding any sort of extension or flare would only effect frequencies that are lower than the cabs current operational bandwidth. To make up for the 30-60Hz difference in response between the 24" and 36" cab, I think any changes to mouth/throat area would have to occur at the point in the horn path which corresponds to those frequencies... or roughly the last 4½ feet or so of the horn path... Which makes me wonder if one could simply swiss cheese the last four and a half feet of of horn path of one of the cab sides (with a hole saw, jig saw, or whatever) and box in an additional foot or so to expand the cab width in that portion of the path... I wonder if that would make up the difference, or any difference at all? Obviously, it's not a practical idea or suggestion. But, just the thought process is valuable in my opinion and I'm glad you brought it up. :thumbsup:
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

Keryn O'Shea
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Re: retrofitting larger mouth

#4 Post by Keryn O'Shea »

Rich4349 wrote: Tue Nov 14, 2023 9:47 am I had acquired some 24" wide T-48s with 3015LFs...
How many cabs man?
AT8 14", AT10 19", T30 28" LAB12, T48 36" 3015LF, THT 20" LAB15, SLA 4x3"/4x4", CArray 6x4", TLAH, TLAP, J10 FA, J12 FA, OT8 CD, OT12 FA, OT15 CD, SLAP 2x6"/4x6", WH8, DR280 MA, XF210. Next J10L

Rich4349
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Re: retrofitting larger mouth

#5 Post by Rich4349 »

3 - 24" wide.

Seth- wow, what a great spin on this. I was thinking cut open one whole side from the mouth's biggest section (with circular saw plunge cuts so that the side extends the panels full width), possibly extending one more section back, affixing weather stripping to the newly exposed wood, then building an angled, wider mouth that could be attached either permanently with glue and brads, or temporarily with steamer trunk (tension) latches. But I like your Nautilus / porthole idea, too.

I wonder what the effect of combining the narrow width "early" throat with the wider "later" throat and mouth would be?
2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!

Keryn O'Shea
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Re: retrofitting larger mouth

#6 Post by Keryn O'Shea »

Rich4349 wrote: Wed Nov 15, 2023 8:54 am 3 - 24" wide.
Ok, before going crazy man, could a "U" plate be built for three cabs, as in 2 outer cabs at 90 or 45 degrees to the central one? You could build your horn into that, so you don't need to modify the existing cabs
AT8 14", AT10 19", T30 28" LAB12, T48 36" 3015LF, THT 20" LAB15, SLA 4x3"/4x4", CArray 6x4", TLAH, TLAP, J10 FA, J12 FA, OT8 CD, OT12 FA, OT15 CD, SLAP 2x6"/4x6", WH8, DR280 MA, XF210. Next J10L

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Strange Kevin
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Re: retrofitting larger mouth

#7 Post by Strange Kevin »

OK, so you've all got me thinking today, and I made a few Sketchup modifications for us visual learners out here.

as usual you gotta trust that Bill is right, and the correct answer is to V-Plate the T48s for better low end sensitivity.

What does that mean if you only have 3 cabs?

Option A add a panel where your 4th cab would be in the stack and enjoy.
Option A
Option A
Option B is more fun, I'm naming this setup "The Scorpion"
Unfortunately, this setup is probably not recommended as the center cab is half in, half out of the vplate.
Option B
Option B
Option B..
Option B..
If I understood Seth correctly, Option B-Plus incorporates a little of what he was talking about with extending the width (height) of the 2 cabs in the V-Plate. shown here in red is a 10" (tall) panel added to the 2 lower t48s.
There may be some merit to this idea. unknown.
Option B-Plus
Option B-Plus
Option Extend-O flaps.
Option Extend-O flaps.
Back to the original idea of extending the mouth area of a pre built cab...
I envisioned something like this, where you could cut away part of one side (or both I guess) to reveal the last half of the horn path and extend panels 5 through 10 a few inches to achieve your desired mouth area.
I fear you would be left with a very interesting looking cab, but I am curious to learn if this could be a viable alternative to rebuilding a compleet wider t48.
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Main Rig - 6 DR200s - 6 T48s (30")
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Seth
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Re: retrofitting larger mouth

#8 Post by Seth »

Kevin! I love that you ran with it! You nailed the rendition of the picture i had in my mind about adding width to the last 4½' of horn path. Amazing!

As far as combining and V-Plating an odd number of cabs, I think the cleanest way would be to place the cabs side by side upright on the ground, tilt the lot of them forward 45°, and put half V-Plates at each end.

More to say about your post... tomorrow. :D
Build in process - 2 WH6, one Alpha 6a loaded, one PRV Audio 6MB250-NDY loaded

Two 2x6 shorty SLA Pro's
One T39, 16", 3012LF loaded
Tall AutoTuba, 20" wide, 2x 8" MCM 55-2421
TruckTuba, 8½" wide, 2x 8" MCM 55-2421

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