On Sunday 22 July 2012 22:14:58 Al Thompson did opine:
> On 07/22/2012 06:12 PM, Chris Bannister wrote:
At which point I have to tell a story. In 1960, I worked for a bit at a
HiFi store at 5150 El Cajon Blvd in San Diego, CA.
At that time the newest pretender to the king of the hill was a box with a
10" driver & dual tweeters. About a 2 feet square face and about 14"
deep, a ducted port bass reflex made by Bozak. The store owner was an
experimenter, so he bought 2 of them, and took one of them apart. He added
some cross bracing to help solidify the panels by coupling each with glued
in bracing to its opposing face, then since it had lots of crepe paper for
internal sound absorbsion, he added about 2x more of it. And he'd ordered
the long throw version of that bass driver, the B10-AL to replace the more
limited throw std speaker. The AL could be driven 3/4" in both directions.
After giving the glue a day to set, a dynaco amp was hooked up along with
the bench audio oscillator, and that puppy amazed us. Using a decent
volume level at 100hz, the oscillator went down, clear to 10hz, without
detecting any of the bass reflexes normal peaks and valleys below 60 hz.
At 10hz, we could hear the air chuffing thru the port, but more
importantly, the room seemed to be bouncing. Hooking up a turntable
typical of then, a Weathers cartridge in a 16" fairchild arm on a 16"
Battleship turntable, he got out the Command record of various instrument
solo's with emphasis on orchestral drums. At the end of the kettle drum
solo, we heard and felt something we had never heard or felt before,
because in the std speaker that looked exactly like the rebuilt one, the
end of the drum solo was when the drummer took his foot off the head
tension pedal, you could hear the squeak of the linkage. Pick the needle
up and move it back 20 seconds and switch the rebuilt speaker in. That
kettle pair seemed to grow cajones with the switch, but the surprise was
that after the squeak of the pedal release on the big one, the player had
given the slack head another whack. The whole room bounced.
So it can be done, if you are willing to pay the piper. That one went on
the show floor that evening, beside the std one that sold for $245 each,
with a $500 tag on it. He got to do it again, because the guy who gave him
$500 for that one wanted another just like it for his stereo system, for
A walk down memory lane, to a different time & place.
While I was in San Diego, one of the other things I did was help build a
couple tv cameras. They were on the Trieste when it went into the mohole
in Feb 1960. No one has been back since till James Cameron went down about
a year ago now. Water isn't compressible? Ahh, but it is when the
pressure against the hull is 18,000 psi. So was the hull, it bent the
frames of the equipment racks.
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: is up!
"I ain't broke, but I'm badly bent."
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