Altec A7 Cabinet versions

[maple5438]

Hi
I have met this fellow who has 2 pairs of A7 cabinets for sale.
One is older and made of plywood and the other is MDF.
Which type should I choose and why?
Or does it even matter?
I need an answer soon before someone else snatches them up?
Thanks

[MikeInNH]

For home use, get the MDF. MDF is better acoustically. The reason speakers are made of plywood is for shear strength. If you plan on moving the speakers around (like a band), then get the plywood, it'll last a lot longer then the MDF.

[Altec19]

From an acoustic perspective, go with the MDF. Plywood can have internal voids and is generally more flexible (which is bad) than MDF. I think all of the later cabinets were MDF but I may be mistaken.

[maple5438]

Thanks for the quick replies !
One other question,
Is there a list somewhere of all the different a7 cabinet revisions?
How can I identify whether these are 825 or 828 cabinets?

[Altec19]

The removable back panel on 825 cabinets is only half height. Because of the addition of loading skids on the back of most 828 cabs, the entire back panel comes off. I don't know if that's a completely accurate way to tell but I think it's generally true.

[Altec19]

Try this site for some solid information:

Sound Practices

This document in particular:

Small VOT PDF File

[dgwojo]

I have the plywood and the MDF versions, I keep the plywood ones around for the 15" frame Altec woofers, those won't fit the MDF cabinet without drilling new holes in the woofer baffle. The 16" frame Altec woofers fit both versions of the cabinet. Dave.

[maple5438]

Thans to everyone who responded.
I checked them out, and chose the mdf cabinets.
They match the dimentions of the 828 perfectly.
The only differences between these and the 828 plans that I have are;
Horn flairs are not closed off.
5/8" mdf instead of 3/4"
I can see these will need some aditional bracing.
Now all I need to know is what is the best method to brace and modify these??
I plan to use 515-8G drivers which these cabinets fit as someone pointed out.