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Newsgroups: net.audio
Subject: Audio anecdote of the 
Message-ID: <1533@teddy.UUCP>
Date: Tue, 29-Oct-85 15:57:53 EST
Article-I.D.: teddy.1533
Posted: Tue Oct 29 15:57:53 1985
Date-Received: Thu, 31-Oct-85 09:09:01 EST
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                         Audio Anecdote
                             of the
                           

This 's topic:

                           Chrome-Dome
                               and
                     The Use of Loudspeakers
                               as
                        Offensive Weapons

The last two anecdotes dealt with the problems dealers and custo-
mers  face  when  dealing with manufacturers. This , we
take a look at some of the the problems dealers and manufacturers
face when dealing with customers.

The main character in our story here was  a  young  (high-school)
kid subsequently dubbed "Chrome-dome". Here is his (our) story:

Way back when, shortly after I and several others had  started  a
high-end  hi-fi  store  in Boston, we were selling, amongst other
things, the then  completely  new  Yamaha  electronics  line  and
Celestion  speakers. For those who may not be familiar with them,
Celestion, at that time, made a line of  speakers  that  combined
reasonable  accuracy  with  high  efficiency and remarkable power
handling. The top of the line speaker, the Ditton  66,  consisted
of a 12 inch woofer/passive radiator bass system, a phenominal 2"
dome midrange that would handle untold power,  and  a  very  wide
band uncollored 1" dome tweeter.

One day, this kid walks in, carrying  a  copy  of  Pink  Floydd's
"Dark  Side  of  the Moon". Seems he's looking for a killer hi-fi
system. He had been sold on JBL speakers and  Phase  Linear  amps
and  Crown  preamps at another store.  His budget, unfortunately,
was about 40% shy. We suggested he listen to a  system  comprised
of  the  Celestion  66's and a Yamaha CA-1000 integrated amp. The
combination (once he got done with turntable, et al)  was  within
his  budget, the only remaining task was to convince him that the
system met his needs.

He handed us his record, and we said we already had a  new  copy.
"No,"  he  said,  "I don't trust stores' records, they're usually
awful." OK, we say, we'll play yours. To this person, record care
was  something you did with stuff you scrape of your sneakers and
apply with 40 grit sandpaper! He agreed that his  record  was  "a
bit  worn",  but  that was done by another store. We put our copy
on, and he was happy.

While it was playing (fairly loud), he asked that  it  be  turned
up.  Up  it  went.   Not  loud  enough for him, he wanted it even
louder. At this point the  level  was  approaching  painful,  but
there was plenty of reserve left in the Yamaha, so we didn't care
much. It was far louder than we had ever listened to things,  but
we  were  amazed  at  how  the  speakers  were managing to handle
things, and they showed no signs of distress. Louder and  louder,
he wanted things.

He was not convinced until  the  strangest  thing  happened.  The
Celestion  speakers  were  sitting on a couple of short pieces of
2x4's because, sitting directly on  the  floor,  the  bass  could
sometime  be  overwhelming. The 2x4's seemed to cure the problem.
Well, whoever had set up the speakers  didn't  have  them  seated
squarely,  and,  during  a  particularily  loud passage, the left
speaker slipped of one of the 2x4's, and, rocking on the verge of
total imbalance, proceeded to walk forward about a foot or so!

Well, this kid was impressed beyond recovery. At that  point,  he
took  out  his and paid us for the system, cash! This despite our
repeated attempts to convince him that  the  speaker  had  merely
slipped, and wass not walking under its own bass prowess!

He took the system home, and immediately called us up to tell  us
how wonderfull the system was.

For several weeks we heard nothing. In the interim, it seems  his
father  had  gotten  sick and tired of his hippy kid playing that
rock music at deafening levels. So he grapped our  hero,  dragged
him  to  a  barber  shop, and had his hair cut. This kid ended up
with a crew cut the of which there has never  been  any  whicher,
before or since. I doubt there existed a single folicle exceeding
1/16"! At his next visit, we didn't even recognize him.  He  said
of  his  fate,  "Well, I guess you guys can call me Chrome-dome!"
The name, of course, immediately stuck fast.

This visit of his was not all that humorous. It  seems  that  the
speakers  didn't  sound as clear as they once did. A quick listen
revealed the problem: the tweeters were very thoroughly fried. We
replaced them no charge, and advised him that he should excersize
some caution. He went away happy, while we tried  to  figure  out
how he had managed to fry two tweeters.

A week later, our friend was back.  Same  problem.  New  tweeters
were  installed.   This  time,  he  was required to pay for them,
since the problem seemd not with the equipment. At $36  a  crack,
this  was  to become an expensive lesson to learn.  The next day,
he was back again. This time he brought his amp along. I  checked
it out, just to make sure that it was not unstable or oscillating
or anything like that. Well, we had warned him, and told  him  to
get his $72 ready. I retired to the lab to replace the tweeters.

WHen new units had been installed, I tested the  speakers.  There
was  no  high  frequencies  still, and the midrange sounded truly
strange!. I quick checked the feed  to  the  tweeters  and  found
nothing.  So, out came the woofer, and all the damping, and there
was the crossover before me, or what remained of  the  crossover.
Both  high  frequency pass capacitors were gone. Simply not there
anymore, quite totally in absentia.  One  of  the  midrange  caps
looked  more  like  a sausage than an electronic component. There
was the unmistakable odor of burnt plastic, and the rear wall  of
the  enclosure looked like it had been hit by shrapnel. And there
was a lot of paper and aluminum confetti just floating about!

Well, Chrome-dome was put on the hotseat.  "What  happened?",  we
drilled.  After a few minutes of questioning, he revealed that he
like to play his harmonica along with whatever music was playing.
And,  conveniently,  the Yamaha amp had a nice microphone jack on
the front panel. Well, visions of infinite feedback squeal danced
in our heads. Sure, I thought, that might be enough abuse to send
an amp so far into clipping that it might destroy some tweeters.

He even agreed to demonstrate. We,  instead,  suggested  that  we
show  him  how, if he really had to do it, how it should be done.
He hauled out his microphone, and we plugged it in, and carefully
turned it up until it was at the level he wnted it at. The volume
control was at about 2/3 full. He said, "No, that's not how I  do
it." At which point, he removed his microphone, turned the volume
all the way up, and proceeded to slam the  microphone  plug  back
into  the  jack.  There was, of course, a deafening "KABOOM", ac-
compinied by a very sharp but muffled  "CRACK".  Simultaneous  to
this  was  the unmistakeable ring-like flash of light acround the
periphery of the tweeter domes, signalling that the  tweeters  in
our  floor  models  had  gone  to  join their compatriots in some
direct-radiator nirvahna. A few seconds later,  we  detected  the
strong  odor of burning plastic, tempered by a slight acid smell.
Our floor models were destroyed! The capacitors  had  been  blown
apart, in one case fracturing the crossover PC board!

And there, next to the Yamaha, which had shut  down  in  protest,
was  Chrome-dome,  smiling  his toothy grin, saying, "Wasn't that
awesome?"

Dick Pierce