MDF vs. Plywood

[Old Guy]

Mike, I don't think that argument holds water. (MDF does.)

Altec did lots of penny pinching in the late 70's like leaving out the braces behind the A-7's horn.

Altec chose to use plywood for it's professional enclosures for years. The MDF came about in VOT's only after Altec's money problems got worse.

Bear in mind a few years later Urei was rejecting most of the 604's it got.

If you wish to use MDF I have no issue with that. My plywood boxes are what I am happy with and I'd be happy to compare in a shootout.

I don't want to be disagreeable, just want to disagree with you.

[bowtie427ss]

In regard to the stock 19 box vs. a simpler rectangular box. I'd like to maybe make a point in the form of a question. Wouldn't the top portion of the 19 box act UNLIKE the equivalent volume in a simple rectangular box?

My thought is that in relation to the woofer portion of the box, the top volume is somewhat restricted by the "throat" between the 2 enclosures, not to mention the structural integrity resulting from the "throat's" construction.

................ just a musing from my foggy mind

[bowtie427ss]

OG, FWIW, any and every time i've used MDF, it has always been about the money. Simply put MDF allowed me to build things at times i otherwise couldn't have.

[gamalot]

I don't have any real 19 cabinets here now but I know the set I bought back in 1976 had no MDF. They were particle board and I think the baffel was ply.

I am wondering the same thing BT. My opinion is the openings in the two boxes might add some interior volume but it appears to be a place for waves to get screwey in and also detracts from the integrity of each box.
I am thinking along the lines of keeping both boxes solid, attaching them the same way and what ever volume I might loose may not be that important.
We need a guru here to figure some parameters and help us with answers.

[Altec19]

If you want to build cabinets that sound like a Model 19 they'll at least need to have the same interior volume as factory 19's. I suspect the "two box" design was largely dictated by aesthetics rather than acoustics and it seems to work fine on both accounts. But a less complex single box design still needs to duplicate the interior volume to produce "the sound".

[quindecima]

Gary,

Why dont you take the total HxWxH of the two 19 boxes and make them just one. Thats what I did, you could inlet a black formica spacer to look like the separation on the 19's. A shelf rabbited in to the insides would keep the base enclosed and brace it considerably. Then again it might not be easier and it wouldn't look exact. I know what you mean, the 19's do look good. I hope to have my other spkrs finished this weekend. If so I will send pics.

[speakerdave]

Gamalot: "Whats some opinions, necessary or not?"

No, it's not necessary.

David

[MikeInNH]

Altec did lots of penny pinching in the late 70's like leaving out the braces behind the A-7's horn.

<font size="2" face="Verdana, Helvetica, sans-serif">There are a LOT of other and BETTER ways to cut costs then to use MDF for plywood. Using MDF had very little yeild in cost cutting. They could have used a stamped steel basket for it's woofer instead of a cast aluminum...that would have saved them 2-3 times the cost savings over using MDF...There are many more also.

Altec built in my opinion one of the finest speakers you could buy at the time. And some 30 years later still one of the best speakers you can buy. And they used MDF because of cost??? As a VP of engineering...I'd fire someone who works for me if he/she made a decision like that.

Altec chose to use plywood for it's professional enclosures for years. The MDF came about in VOT's only after Altec's money problems got worse.

<font size="2" face="Verdana, Helvetica, sans-serif">Altec chose plywood for it's pro-line because of it's durability. NOT for sound quality. Plywood will hold up a lot more to the abuse of a sound crew moving the speakers around then MDF ever will. And playing those speakers at the volume they played them at any sound added by the plywood would NOT be heard.

If you wish to use MDF I have no issue with that. My plywood boxes are what I am happy with and I'd be happy to compare in a shootout.

<font size="2" face="Verdana, Helvetica, sans-serif">As I said..there is a difference but it is probably so small a difference you may not be able to hear it.

[gearjammer]

I have a mint pair of 19's in service as well as a second pair I picked up a few years ago sitting in storage waiting to be resurected. They are both particule board with no plywood at all. Also they were built with little to no bracing. Sure they sound great but once you get past the fine veneer on the cabinets, they are very simple boxes with not much else going on. Now I hope no one starts ranting about these facts but this is just the way it is, and that is a fact. If I was going to clone a pair I would try to make exact copies from the outside but apply more bracing to interior as well as caulk and seal all the internal joints. And I will repeat this, they are very simple boxes and not complicated at all.

[gamalot]

Thanks for the info Gearjammer, I was not 100% sure about mine except I know they had ZERO MDF.
I did think the front baffle was Ply but again I could not remember for sure.
I do suppose just about anything or material was possible durring the manufacturing period of this model.
Given stories I have heard from others, nothing would suprise me.
It would be nice to think that all model 19s were created equal but we already know there were many component changes thru the life of the line.

Gary