$325 Lab 12 based PA tapped horn. ~35hz extension - Page 3 - diyAudio
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Old 19th March 2013, 06:45 PM   #21
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I need to mess around with the mouth exits and see what results I get. I am confident the fold / taper is okay for the cabinet.

Then maybe a little EQ and I think this will be a winner. If not, ohh well! Try again!
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Old 19th March 2013, 06:50 PM   #22
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Originally Posted by m R g S r View Post
Art,
Thanks for the tip. Any suggestions for placement of the keystone in relation to the driver? Or keystone cutout area?
The Keystone exit area should be similar to the predicted area to start with.

The aspect ratio seems to be related to path length vs cabinet height and width, examples of a 2x10" (26.5 x 22.5 x 15 inch deep) and the 18" (26.5 x 45 x 22.5 inch deep) below.

Relationship to the driver? "It depends".
The 18" (or 2x12") have the drivers and the upper portion of the exit in the upper half of the cabinet, the 2x10" in the lower half.

That said, I experimented with a lot of shapes and sizes with both, each required a different compromise.

One tip, listen to each change before saving the test result, early on I had one test that the upper response looked much better (a dip had filled in) turned out it was a pipe clamp resonating against a panel .

Hope you have a lot of clamps!

Art
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Last edited by weltersys; 19th March 2013 at 06:55 PM.
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Old 19th March 2013, 06:59 PM   #23
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Thanks for the tips!

I have a few clamps
Click the image to open in full size.

Click the image to open in full size.
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Old 19th March 2013, 07:22 PM   #24
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Thanks Art!
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Old 19th March 2013, 08:13 PM   #25
Xoc1 is offline Xoc1  United Kingdom
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Hi m R g S r
Looking at your fold in Post 8 it looks like the S3 corner where you have positioned the reflector the reflector panel is too big, and is causing a restriction. Also it looks like the centre panel in the first corner after S2 could benefit from being a bit longer - but of course I could be seeing distortion due to the photograph. Fairly sure that the reflector corner is a bit tight though. Are you planning to fit a castor on that corner?
Regards Xoc1
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Old 19th March 2013, 08:28 PM   #26
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I want to use casters, which is the purpose of that reflector panel. Once I get the casters I can mock up and make that panel as small as possible just enough to fit the casters.

It did appear to me that it was causing a slight restriction so I already thought of making that panel smaller.

Do you know if there is a minimum area which should be maintained around the turn in order to not restrict?
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Old 19th March 2013, 08:32 PM   #27
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If I remember correctly the center panel is 22.75"

I could add an inch to that and take an inch off the bottom of the left panel, closest to the reflector. That would reduce the restriction there...

Last edited by m R g S r; 19th March 2013 at 08:36 PM.
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Old 19th March 2013, 09:45 PM   #28
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Originally Posted by m R g S r View Post
If I remember correctly the center panel is 22.75"

I could add an inch to that and take an inch off the bottom of the left panel, closest to the reflector. That would reduce the restriction there...
That wouldn't hurt, as the middle panel first turn looks to be oversized.
As a rule of thumb I have just tried to make the area an even expansion from beginning, to middle to around the corner- the caster turn was almost doing that already.

One suggestion to keep the caster panel from punching through when hitting ramps, use 45 degree angles on the caster panel so there is maximum wood overlap when in the tilt back position.

Last edited by weltersys; 19th March 2013 at 09:53 PM.
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Old 19th March 2013, 09:56 PM   #29
Xoc1 is offline Xoc1  United Kingdom
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I dimensioned up one of the TH18 corners to give an idea of how to check the expansion around the corner
Regards Xoc1
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Old 19th March 2013, 10:00 PM   #30
ogie is offline ogie  United States
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