From obxwindsurf@yahoo.com Thu Jan 08 08:17:19 2004
Subject:Re: Is this boiling down to a vintage vs. modern audio discussion?

Now that I've had time to digest this I've rethought my position -
this is my story and I'm sticking to it. For whatever it's worth to
the rest of the group....

After looking at your responses below, I realized that I wasn't even
talking about the LoPro/Pro 3T in the first place. I believe the
original thread of the discussion centered around the MS145 and NOT
the LoPro/Pro 3T. My remarks were geared toward the differences
between the sound of the Leslie 145 and the MS145

If you're looking for a cosmetic finish (i.e. staining and finishing
the natural woodgrain) no matter how good MDF is for building speaker
cabinets (and it's about half the price of furniture grade cabinet
plywood) MDF looks like hell when stained and varnished :) There is
no myth that the original Leslie designs had to fit into settings
where they would harmonize with the furniture finish of the Hammond
and not clash with its surroundings.

MS made theirs road-rugged with MDF (and/or particle board, with the
exception of the Low Pro as you describe), vinyl, and metal corners,
because quite frankly a Leslie looks like shit after months
transporting to and from gigs - that is unless you have an expensive
case to put it into. Mine cost about $1000 to build from scratch - I
didn't have the cash to invest another $500-1000 for a case. If I had
that I would invest in more and better instruments to run through the
Leslie - I elected to buy a PC and B4 :)

The Leslie is not a properly designed bass enclosure - ported, yes,
but even the Leslie's original design intent was based around it
being a "musical instrument", not a sound reproduction system. The
wood introduces nuances and resonances into the sound. The question
was "what makes the sound different?", not "which one is better?".

While titanium drivers and phenolics >>reproduce<< accurately, The
frequency and overtone spectrum will be different over the useable
range. I never said that titanium drivers didn't reproduce sound
accurately, only that they were different. The difference between
phenolics and titanium is analagous to the difference between tubes
and solid state when they are not driven into distortion. Both types
of amps reproduce their designed frequency range, each just
introduces nuances which characterize their sound. Both types of
drivers accurately reproduce their designed frequencies, just
different. My own opinion, having built Leslies with actual Leslie
rotor components and using a titanium driver vs phenolic: I like the
phenolic better but that is just my preference. High-energy midrange
drivers are not intended to reproduce to exacting audiophile
standards. There is NO driver that has a perfectly flat frequency
response over its range. That in itself is an unattainable holy
grail.

Openings are not openings - the acoustical properties of slots,
louvres and open panels vary widely. Just ask any acoustic guitar
designer. Ovation has a reason for their "non-standard" openings, so
much so that they more than likely have a patent or trademark on it.
More importantly the wood material left between slot openings
resonates and introduces its own nuances to the sound. Remember the
question was "why do they sound different?" NOT "which one is
better?".

Regarding crossover slopes: the steeper the slope, the faster
attenuation of frequencies occurs for the woofer above the crossover
frequency, and the compression driver below the crossover frequency.

With regards to the woofer, a shallower crossover behavior will allow
some of the frequencies which are intended for the horn to also be
reproduced, albeit rather poorly by the woofer. With regards to the
horn, this is a little more hazardous, as the shallower crossover
slope means that low frequencies intended for the woofer make their
way into the compression driver, increasing excursion beyond what the
horn was intended to do. Any loud speaker is essentially a linear
motor from a mechanical standpoint. Amplified sound into a voice
coil produces electromagnetic field that interacts with the permanent
magnetic field of the speaker.

If the coil/diaphram bottoms out due to excursions resulting from
frequency/wattage combinations outside of the design of the driver,
it WILL BURN OUT.

If you go back to my original post, I wasn't arguing the MS crossover
design - I had actually said that I was sure that the MS used at
least a 2nd order crossover and didn't expect differences in this
area to characterize sound differences.

But... and most importantly... I wasn't even remarking on the
LowPro/Pro 3T combination. The original discussion was on the MS145
and NOT the LowPro. Since my remarks were directed at the MS145 we
have no argument. I don't ever remember saying the MS units were
junk.

Remember I was responding to the question of "why do they sound
different?". My responses were based on my ***experience*** building
Leslies with different materials mostly in the cabinet, selection of
drivers and crossover, and in some cases the materials the low rotor
was made of, but retaining the use of stock Leslie rotating horn,
motors, belts and cabinet dimensions to get as close to stock sound
as possible.

Believe me, I was seriously looking at Motion Sound, Low Pro and Pro
3T. Quite frankly however, it's easier to sell to your spouse $400
worth of Leslie rotors and motors that evolve into a $1000 project
that works VERY WELL, and KICKS ASS by my standards, than $1800
of "unnecessary" expenditure.

Which one is better? Who cares? That's a question answered by
personal taste. My personal taste is that my homebuilt Leslie, made
of wood, to 145 dimensions, with original motors, rotors, bearings,
and belts, and modern speakers and amplifier exceeds my expectations,
looks great, and I have spent $800 less than I needed to :)

If you are happy with your Motion-Sound purchase and its performance,
great! It's good to be satisfied with what you got when you spend
that kind of money.

Regards,
Kevin

--- In CloneWheel@yahoogroups.com, "Karl M" wrote:
> Karl