Plywood or MDF?

[jonkun227]

 

[Geoff H]

It's not just a windoze logo, it's the latest version, incarnation, corruption, whatever. Can I borrow it?

I have to agree with Cal's first comment. I think we have to face the fact that timber has it's problems, and we need to find something that is acoustically inert.

The only ply I can get locally, is pine, and is supposed to be void free. It's not.

In our southern states, most hardwood is kiln dried. When I moved up the coast I was surprised they (mills) don't KD as a rule, as the moisture take up in the higher humidity, sub tropical climate negates it.

So that rules out an idea I had, diagonal planking.

The best baffles I have had to date were 20mm fibro-cement.

Geoff.

BTW, that logo's not the best I've seen. An animated gif of an arctic bird doing something rather unsavoury with a flag.

 

[Bbisig]

I Like MDF. It is easier to cut and work with than ply but cracks very easily.

 

[Upstate NY low life]

Speaking of filling it in, instead of sand aren't you supossed to take two layers of plywood spaced a few inches apart and pour concrete in between them?

 

[Cal Weldon]

Speaking of filling it in, instead of sand aren't you supossed to take two layers of plywood spaced a few inches apart and pour concrete in between them?

Doing that allows for future delamination. Delamination allows for vibrations.

Sand on the other hand will continue to settle, leave no voids and never "buzz".

 

[TerryO]

A couple layers of plywood bonded with construction adhesive sandwiching a thick blue insulation billet or sheet is quite stiff, very light, transmits very little vibration and should be quite stable as it doesn't absorb moisture. It would need a lamination of thicker plywood in the area where you mount the driver, just to supply some "meat" for the mounting screws or bolts.

I built my last float for the kids a few years back using this foam, with some manpower supplied by Adire and Exodus Audio (I supplied the materials, tools, beverages and BBQ).
Even unsheathed, the blue foam hasn't absorbed "any" water after 5-6 years in the water.
I'm sure that Cal Weldon has seen insulated roofs using similar construction and can testify to it's suitability (or lack of, for that matter).

Best Regards,
TerryO

 

[doorman]

Surely you're not suggesting Cal's an expert at "absorbing liquids"?!!
Best,
don

 

[Irakli]

I use two 3/4 plywood panels glued together for sub walls. 1.5" thick panels plus good internal bracing and the walls are dead, dead, dead.

 

[Cal Weldon]

Surely you're not suggesting Cal's an expert at "absorbing liquids"?!!

Damn. At my age I should no better than to post in a public forum shouldn't I?

 

[TerryO]

Surely you're not suggesting Cal's an expert at "absorbing liquids"?!!
Best,
don

Don,

Unlike our native slugs and snails; wherever Cal goes, he leaves a trail of parched earth and dust.


Best Regards,
Terry

 

[Wavebourn]

I prefer concrete for woofers. Speakers are stationary devices, as well as fireplaces. However, you can buy some fake portable fireplaces, but fake thing always will be fake...