[BEAR]

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bear wrote:

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BEAR wrote:


BEAR wrote:



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Its funny you should say that because Erath is now using an improved
version of his LWE feedback system on his new "Trout" loudspeakers;
they're a small, two-way, active system that use an 8" woofer and a
planar transducer. They go from 20hz-20khz all by themselves or with
an external 10" large X-max woofer in a tiny 14" cube.

I recently heard a pair of these and they sound pretty impressive.
Somebody close to where I live in Dallas just got a pair and invited me
over to check them out.

http://www.dontgethungup.com/wbcam/trouts+LWE-Is_01.jpg

I thought it would be fun to bring over my LWE-Is to compare since I
just scored an original LWE-I amplifier
off ebay:

http://www.dontgethungup.com/wbcam/lweamp01sm.jpg

I forgot how heavy the LWE-Is are though....good god!

Of course the Trouts sounded much better than the LWE-Is. As you can
see, the setup wasn't ideal, but I was a guest.

Erath's literature says that his improvments in the feedback system
focus more on minimizing harmonic distortion than with the LWE-I which
was mostly to improve bass response. He says that he can really hear
the difference between the SACD and CD tracks on a hybrid SACD. He
named them after the Schubert Quintet I'm pretty sure.

To answer your question, I'm sure there is definitely feedback, now is
it a precise measurement of the position of the speaker cone? Since
the "sense leg" is probably is based on a voltage reading accross voice
coil (in the case of the woofers) I guess it can't be as precise as an
accelerometer or the other methods you mention, yet it sounds
incredibly good. I agree with you that it should be tested as I'm
curious as to how effective it really is in reducing harmonic
distortion. If there is feedback, is it considered "motional
feedback"?

I think Erath's gift is his ability to "massage the circuitry" (as you
so eloquently put it!) because even my 40 year old LWE-Is with their
rather humble vintage components sound remarkably good. Its like "the
whole is greater than the sum of its parts" saying.

Thanks, and happy new year!...lets hope 2007 goes well,
-Sam

Should be fairly simple to measure.

There are a number of freeware FFT software/souncard measurement PC
based systems on the internet for download. That and a relatively cheap
microphone (solder, opamp, battery and $1 Panasonic element + straw =
measurement mic) DIY or storebought will give you more data than you can
shake a stick out.

That will do frequency response, impulse response an waterfall.

That will tell the entire story pretty fast.

I don't suppose Erath publishes those measurements?? I did not see much
on his website...

_-_-bear