[Hallicrafters] Now R-42 speaker construction

[rbethman]

Folks,

I own and use several of these venerable old workhorses.

1) I have YET to fins ANY wood in their construction!

2)  The phase concept and ducting for "Bass Reflex" has been known for a 
LONG time.

Carl - better lining can only improve what it already does.

A wood enclosure "may" even improve it more, but I'll leave that up to 
those whom want to reinvent the wheel.

Bob N0DGN

Duane Fischer, W8DBF wrote:
> The Bass Reflex cabinet does not depend on sound absorbing material 
> for what it does. It uses the aprox. 20% of the sound off the back of 
> the speaker cone that is wasted, puts it in phase with the sound off 
> the front of the speaker and in doing so adds an appreciable gain in 
> the low midrange and bass response.
>
> This is accomplished by using a cabinet constructed of a heavy hard 
> wood that contains a fixed volume of air, said volume partly 
> determined by the size of the speaker cone, and either a certain 
> diameter circular front port that puts the cabinet air in phase with 
> the air off the front of the cone or a tuneable cylendrical tube 
> mounted in the front cabinet port hole that allows the user to 
> manually tune the interior volume to cause equal sound phasing. The 
> second method eliminates the need for a cabinet of a specific size.
>
> The purpose of a Bass Reflex cabinet is to utilize the wasted sound 
> off the back of the cone, not eliminate it by the use of sound 
> absorbing material. If you do that, then you end up with an infinite 
> baffle cabinet.
>
> Take your pick; infinite baffle, ducted port or folded horn. They all 
> have advantages and disadvantages. Your need determines which is best 
> for you.
>
> Duane Fischer, W8DBF/WPE8CXO
>