From rockkey@sbcglobal.net Sat Oct 11 08:01:25 2008
Subject:Re: 145 vs 147

Ryan,

No, I don't think so (about the nest, that is). Those holes and
diagonal cut-out are vents. Bass reflex or vented enclosures are
pretty common. The vent "tunes" the box resonant frequency to extend
and shape the low freq response. Every box/driver combination may
potentially require a different size vent. I don't know that it would
make a huge difference but I'd go so far to say that when one changes
the LF driver to something other than stock, the cabinet may benefit
from an analysis and possible change in vent dimensions to optimize
the new box/driver combination's response.

Here's an excel spread sheet that I've used to compare box/driver
combinations. For my needs I think it's pretty good.

http://www.pvconsultants.com/audio/boxmodel/unibox.htm

I don't have any specific opinions but it might be interesting to see
how the enclosure volumes,vent sizes and driver types correlate in the
different Leslie models you mentioned.

Hmmm, maybe you're right about that hornet's nest: )

Cheers,
Rock

--- In CloneWheel@yahoogroups.com, Ryan Stroup
wrote:
>
> I could be stirring up a hornet's nest with this but I've always
> wondered why the 145/142 cabinets had no diagonal cutouts for bass
> porting, only a small cutout on the back panel. In the the 45 and 44W
> cabinets, there is a single diagonal cutout on the front right
corner of
> the cabinet. In the taller single speed Leslies, the lower shelf had
two
> diagonal cutouts and the taller two speed cabinets only had a single
> diagonal cutout on the back right corner. This could be just subject to
> personal preference but I've found that Leslies with the diagonal
cutout
> have better bass response. I'd be interested in hearing everyone's
> experience.
>
> --
> Ryan
>