From rockkey@sbcglobal.net Wed Jul 12 14:03:04 2006
Subject:Re: Was difuse: Now to reflect or not?

Bruce,

You make a good point, I never measured the difference either
but one of these days I'll get a replacement horn and I'll A/B my
Leslies and check out the differences.

But as far as preception goes if it sounds louder and doesn't
measure louder, well who cares then what the SPL is? If it
sound louder it sounds louder.

As far as the back off/on is that real or perceived loudness : )

But don't get me wrong, I think it's great to kick around these
ideas but in the end it's up to each of us and our own ears.

The whole preception thing can get pretty crazy. A book
recomended to me, Tuning,Timbre,Spectrun,Scale by William A.
Sethares, gets into it. It's kinda pricy and my local lib. didn't have
it but a search turned it up at a local university. Check it out.

Rock

--- In CloneWheel@yahoogroups.com, Bruce Wahler
wrote:
>
> Hi,
>
> The only problem with the projection argument is that it's more
perception than reality.
>
> The reflectors don't reduce the SPL to any significant degree;
they just bounce the sound in another direction. Since a Leslie
is spinning in 360 degrees, the NET sound pressure will be
about the same: sometimes the horn facing you will bounce
some of its sound elsewhere; other times you will pick up extra
sound being bounced from the horn when facing another
direction. I've never measured the difference, but I'd be willing to
bet that it's about 1dB -- barely noticeable. The only times that an
open horn is a benefit are: 1) when stopped, and facing at the
listener; and 2) if a mic is shoved almost up against the horn. If
the Leslie is turning a lot, #1 rarely happens; #2 is not only
hazardous to the horn, but results in a sound (when used
without reflectors) that is extremely choppy.
>
> I still feel that a lot of the tone is lost if the reflectors aren't there,
especially at Chorale.
>
> Regards,
>
> -BW
>
> --
> Bruce Wahler
> Design Consultant
> Ashby Solutions™ http://consult.ashbysolutions.com
> 978.386.7389 voice/fax
> bruce@...
>
> At 02:57 PM 7/12/2006 +0000, you wrote:
> >Jeff,
> >
> >I think it's a matter of projection. That is with the backs off,
turned
> >backwards, deflectors long since gone is just standard
> >opreation procedure if you're going for all the volume you can
get.
> >If you mic it you might still want the extra for stage volume.
(I've
> >thought about installing mics inside on mic holder flanges.
I've
> >even got a flange in my parts box, I just need to do it.) I think at
> >lower levels in a smaller club or at home running it like it was
> >designed makes perfect sense also. A simple test you can
do is
> >just turn it around a few inches from a wall. I think you get
more
> >of a smoother "3D" sound front-wards comming through the
> >louvers even with the deflectors off. It's probably smoother
with
> >them on. JMO
> >
> > --- In CloneWheel@yahoogroups.com, "jhgstudio1"

> >wrote:
> >>
> >> Ironically My top horn reflectors were taken out by a sm57
> >microphone
> >> in the early 90's. I guess that is a popular leslie related top
> >horn
> >> refector fatality. But my topic has spurred yet another
question.
> >Back
> >> Panels on or off. My 145 never had them while I've owned it
and
> >I've
> >> been draggin' the thing around for 12 years. BTW thanks for
all
> >the
> >> input everyone.
> >>
> >> Regards,
> >> Jeff Goodman
> >>
> >> Retired Lurker
> >> Recovering from large doses of AM
> >> and aparently not enough FM
> >>
>
> [Non-text portions of this message have been removed]
>