|
Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
|
|
|
Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ. |
|
In Reply to: Re: Cutting plywood that is already painted with Varathane posted by seemunkee on February 2, 2001 at 11:25:36:
My suggestions in the earlier post were based on a couple of assumptions. I should know better!1) On rereading your post in detail, I see the plywood was originally purchases for a table project - how thick is it? is the . Laminate trim router would be recommended only for 1/4" or less material - 1/2" or 3/4" plywood would burn burn it out.
2)Will each section of the stack be finished separately? With an estimated complete weight with drivers of over 400lbs, that would make sense. In that case, there will be more rough cuts on the table saw. Another way to rough cut the material to non rectangular shapes is with the aid of a clamped straight edge, larger HP router and flush trim bearing bit. Again if you don't already have access to one of these, get one. The cost of a single Utopia tweeter is ?$.
3)Is the 32 ft^2 of the plywood sufficient to cover all the desired surfaces? If not then it may be rather tricky to match the grain and finish colour with new material. Perhaps use this sheet for skinning the WATT clones, and buy new paper backed veneer for the big boys. From the most recent pictures on your Utopias, it would appear that you now have access to a decent table saw, or have become very proficient with a circular, and the compound bevels on the truncated pyramids shouldn't represent too much of a challenge.
4) Kudos on the interlocking matrix style bracing, in the photos these appear to be MDF. A suggestion, you might want to try baltic birch for internal bracing in the future - while more costly, it is much stiffer and lighter than MDF. The improvement from this type of bracing is not due to mass, but in the reduction of internal standing waves by breaking up the internal space, and the redistribution of resonant energy of the shell. That energy cannot be destroyed, but it can be transformed. By rigidly coupling the outside case you essentialy create a number of smaller panels, each with a lower amplitude and higher resonant frequency. The goal would be to raise all of them high enough to be outside the pass band of the woofer, and dampen the internal panels with treatment of your choice. Constrained layering can be more effective here than brute force mass, but takes rather more time to affect. But then you already understand the time factor.
Anyway, continued good luck, and keep us posted!
chris
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: On further consideration - CBOB 13:44:58 02/02/01 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
