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Bracing Heresy I?


wuzzzer

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The cabinet walls are short and there are "braces" (screw blocks) at the edges to hold the back and motorboard in the front.  Your best upgrade is to make new, thicker (3/4") backs, or stiffen the back with a diagonal bar, and seal the corners of the screw blocks with a good wood glue that doesn't shrink.  I screwed pieces of the riser base, at an angle, to the inside back of my factory backs to stiffen them.  I can't use the riser bases anymore.  Consider a thin rubber gasket for the back, also. 

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3 hours ago, MC39693 said:

@wuzzzer I think @moray james has done lots of bracing on Heresy, documented some time back, and also on some other forums. Maybe he’ll see this and offer thoughts and pictures?

the brace work is done with 3/4" English white oak which is quite stiff and all the junction points of the walls are fitted with the same material all around the cabinet. This results in both an air tight cabinet as well as a very rigid cabinet with minimal volume used to achieve this. Cabinets were then packed with high density fiberglass oriented such that the soft edge of the fiberglass sheet faces the driver. This is very important as facing the flat and hard compressed side of the fiberglass toward the driver results in much reflection.  I had two sets of H3 which I modified in this way and all four cabinet were from the factory very loose with dry baffle joints. They are very solid now bass impact and weight are much improved. Hope this is of some interest.
 

klipsch 3 brace work.jpg

Heresy 3 bracework 3.jpg

heresy 3 bracework 1.jpg

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The back panel for sure, run a brace between the side flanges flush with the back panel. On the baffle you are relying on the woofer basket, look between the top of the woofer and bottom of the squawker. Run 2 dowels or similar between the bottom of the squawker and top of woofer basket to the added back brace, install 2 new screws through the back panel into the cross brace and be sure to seal (good weatherstripping ETC )  the back panel to eliminate leaks.

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11 hours ago, yamahaSHO said:

This is what I just did on my 1982 Heresy's.  I am also connecting this brace to the rear panel for bracing as well.  Additionally, I will add an adjustable brace for the squawker horn, similar to what is on the La Scala.

 

49784996791_2e3469b06b_k.jpg

you should consider placing cross braces on your front baffle above the woofer and again above the mid horn this is the weakest part of your cabinet.  A vertical brace on the rear baffle will also help you can also install short stringers to connect the front baffle to the central cross brace yo have installed a couple above the woofer will provide the most added stiffness to the front baffle. braces and stringers can be made from plywood, 3/4"x1.25" will provide the best ratio for stiffness.

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15 hours ago, moray james said:

you should consider placing cross braces on your front baffle above the woofer and again above the mid horn this is the weakest part of your cabinet.  A vertical brace on the rear baffle will also help you can also install short stringers to connect the front baffle to the central cross brace yo have installed a couple above the woofer will provide the most added stiffness to the front baffle. braces and stringers can be made from plywood, 3/4"x1.25" will provide the best ratio for stiffness.

 

 

I'm not going to get that far into it.  Additionally, the front baffle is braced by a woofer and horn, which I was already going to support the back of the horn as it's got a lot of weight hanging off it.  I was already going to brace the rear panel due to size and thickness.

 

They already sound pretty good, so I'm not going to fret over every little possible thing that could be done.

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I really like how your doing this but I have a question?
Did you do before and after mic / REW tests ?
I’d like to do my H1’s but I need some hard numbers first. I have sealed them a few years ago and done the crossovers and made sure the rear was sealed very well. But I did not have the test mic and software to do before and after
Thanks for your post and photos


Sent from my iPhone using Tapatalk

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For the H3s I just built, I added a brace and the added about .5 inches to the depth of the cabinet to keep the internal volume

approximately the same as stock.

I also used 1 inch Baltic Birch for the motherboards and backs, the balance was built with 3/4 inch BB.

 

The knuckle rap test says they show no signs of unwanted resonance.

IMG_1787_sm.jpg

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