Please excuse my off topic posting, but I felt that if anyone could answer
my questions they would be either in rec.audio.tubes, or
rec.antiques.radio+phono.

I have come across a set of loudspeakers of very unusual construction.
These things are home-built and a good deal of effort has obviously gone
into their construction. What I would like to find out, and perhaps you
will be able to help, is whether these were hand built to clone some
commercial design, or possibly built to some construction article in one of
the popular magazines.

I have loaded a picture of the baffle from both the front and the side at
alt.binaries.pictures.radio so that you can better understand the
construction.

What the builder has done is to take three Philips drivers, a woofer, a mid
and a tweeter and cut the baskets off, leaving just the magnets and voice
coil assemblies intact. The voice coils have then been coupled to three
separate home-made diaphragms on the front of the acrylic baffle.

The couplings joining the voice coils to the diaphragms are made from thin
metal tubing approximately the same diameter as each voice coil, and are
highly damped by passing through acrylic housings stuffed with soft
open-cell plastic foam, as visible in the rear view. These same acrylic
housings are used to support the driver motors. The diaphragms are tapered,
wider at their bottoms than at their tops, with the smallest of course being
the tweeter. The diaphragms and their reinforcing ribs are thin and appear
to have been fabricated from flattened and polished soft drink cans. Just
imagine all of the possible resonances!

The baffles are mounted to a conventional well built sealed box. Someone
will no doubt ask what these sound like. Not too good. Boomy lows,
completely absent highs due to open voice coils in both tweeters, but the
midrange sounds OK actually.

Has anyone in the group seen anything like these before?

Best Regards : Doug Bannard

Doug Bannard wrote:
Please excuse my off topic posting, but I felt that if anyone could answer
my questions they would be either in rec.audio.tubes, or
rec.antiques.radio+phono.

I have come across a set of loudspeakers of very unusual construction.
These things are home-built and a good deal of effort has obviously gone
into their construction. What I would like to find out, and perhaps you
will be able to help, is whether these were hand built to clone some
commercial design, or possibly built to some construction article in one of
the popular magazines.

I have loaded a picture of the baffle from both the front and the side at
alt.binaries.pictures.radio so that you can better understand the
construction.

What the builder has done is to take three Philips drivers, a woofer, a mid
and a tweeter and cut the baskets off, leaving just the magnets and voice
coil assemblies intact. The voice coils have then been coupled to three
separate home-made diaphragms on the front of the acrylic baffle.

The couplings joining the voice coils to the diaphragms are made from thin
metal tubing approximately the same diameter as each voice coil, and are
highly damped by passing through acrylic housings stuffed with soft
open-cell plastic foam, as visible in the rear view. These same acrylic
housings are used to support the driver motors. The diaphragms are tapered,
wider at their bottoms than at their tops, with the smallest of course being
the tweeter. The diaphragms and their reinforcing ribs are thin and appear
to have been fabricated from flattened and polished soft drink cans. Just
imagine all of the possible resonances!

The baffles are mounted to a conventional well built sealed box. Someone
will no doubt ask what these sound like. Not too good. Boomy lows,
completely absent highs due to open voice coils in both tweeters, but the
midrange sounds OK actually.

Has anyone in the group seen anything like these before?

Best Regards : Doug Bannard



Philips put an awful lot of money in designing very stiff, light cones
on their speakers, and trying to outguess them by providing your own
coil-air interfaces is(dare I say it?) rather stupid.
You will get awful performance at the low and high end, because of
impedance mismatch and multy-resonance for the implemented membrane.
But you could admire the thought if not the results.

In article ,
"Doug Bannard" wrote:

Please excuse my off topic posting, but I felt that if anyone could answer
my questions they would be either in rec.audio.tubes, or
rec.antiques.radio+phono.

I have come across a set of loudspeakers of very unusual construction.
These things are home-built and a good deal of effort has obviously gone
into their construction. What I would like to find out, and perhaps you
will be able to help, is whether these were hand built to clone some
commercial design, or possibly built to some construction article in one of
the popular magazines.

I have loaded a picture of the baffle from both the front and the side at
alt.binaries.pictures.radio so that you can better understand the
construction.

What the builder has done is to take three Philips drivers, a woofer, a mid
and a tweeter and cut the baskets off, leaving just the magnets and voice
coil assemblies intact. The voice coils have then been coupled to three
separate home-made diaphragms on the front of the acrylic baffle.

The couplings joining the voice coils to the diaphragms are made from thin
metal tubing approximately the same diameter as each voice coil, and are
highly damped by passing through acrylic housings stuffed with soft
open-cell plastic foam, as visible in the rear view. These same acrylic
housings are used to support the driver motors. The diaphragms are tapered,
wider at their bottoms than at their tops, with the smallest of course being
the tweeter. The diaphragms and their reinforcing ribs are thin and appear
to have been fabricated from flattened and polished soft drink cans. Just
imagine all of the possible resonances!

The baffles are mounted to a conventional well built sealed box. Someone
will no doubt ask what these sound like. Not too good. Boomy lows,
completely absent highs due to open voice coils in both tweeters, but the
midrange sounds OK actually.

Has anyone in the group seen anything like these before?

Best Regards : Doug Bannard


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[Image]

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Haven't seen anything like that, Doug. For a couple decades I was a
Speaker Builder subscriber (haven't been for several years now), and I
don't recall anything like this appearing in that journal.

Dave