[HAM] MDF

[Peter D Abrams]

John Doyle wrote:

>Most of your questions have been answered except for Why is it bad for
>Hammonds and Leslies?
>
>In my opinion, MDF should not be used in a tone cabinet. One reason is that
>when you cut the louvres the exposed particle board will swell when the
>finish is applied and will look like ca ca. I  have seen this firsthand on a
>new Leslie. Scott H says that the one I saw was a prototype. He's probably
>right (usually is). (even if he is correct about the cabinet, the thing is
>still worthless because they use stepper motors to rotate the speakers which
>brings about all kinds of other problems).
>
I'd like to hear what those other problems are, mostly because......

They aren't stepper motors. 2 Pole squirrel cage motors w/ tach/servo.
Not the most elegant design, and the pulsing technology they are using
could be improved. A lot of things have happened with induction motor
technology in the past few years. This I know

>Secondly, MDF is about as dense and heavy as cement. I would believe that
>the Leslie cabinet was originally designed to resonate slightly in order to
>enhance the sound much like the soundboard of a piano does.
>
It wasn't designed that way! It was what they had to work with, and when
particle board became available they used it. It certainly didn't curb
their sales, and it was cheaper. The best cabs in that regards were the
single speed boxes and early 2 speed ones. After that they went to mdf
(Hello, particle board) for the shelves, and some folks actually route
them out and replace them w/ plywood. The cab *does* make a difference,
albeit a subtle one.

> It is for the
>same reason that many of us like the wooden rotors for the bass speaker
>instead of the styrofoam ones.
>
The prob with the foam rotors is one of mass. That and the oh so early
90's gerry rigged speed control make for a mess. The motors, left on
their own, will spin at 3600 rpm, and will send the cabinet into orbit
if the tachs get clogged (according to Harv).  Some folks use lead (or a
stack of quarters) pushed into the foam to get the ballistics closer to
home.

> The wood adds to the sound quality. Its
>indescribable. Kind of like arguing tubes versus solid state. In my opinion
>tubes sound better, warmer . . . more human if you will. The same goes with
>hardwoods versus MDF when it comes to a Leslie tone cabinet. The Leslie tone
>cabinet is different than a loudspeaker cabinet. A loudspeaker cabinet isn't
>supposed to resonate at all.
>
That's not entirely true, a cabinet will resonate no matter what it's
made of, the trick is *where* and *how much*. But yes, people who have
had a lot of experience listening to the various ages of cabinets favor
the plywood cabs over the mdf stuff. But there are very few folks who
could tell the difference between a '64 122 and a brand new 122A without
other clues. They exist, but I can only name one for sure. And I won't.

>Finally, MDF is fine if you're building a formica countertop or a cabinet
>for a coin operated video game. It's cheap and stable. But if you buy a fine
>piece of furniture, it is almost always made of hardwoods with veneer on top
>in order to get a uniform finish. A maker of fine furniture will brag about
>using solid hardwoods. This speaks of quality. If I was considering spending
>25 thousand dollars on an instrument such as a piano or a new B3 (even if I
>knew nothing about the history of its internal workings) and I discovered
>that it was manufactured from MDF, I would walk away from it.
>
>
Which may be why Ham-Suz chose Swiss Plywood to build all of their new
solid wood B3 cabinets eh?

later,