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[Lance Rectanus]

Going through a bunch of scans of old photos from my wife's side of the family and came across this interesting photo. It is from her Grandfather's vintage. He was a WW I veteran. I'm guessing that it is something sound-related and directional via the turntable that it is mounted on. I'm thinking it's an early attempt at quad-amplification!!

[Keith Broughton]

Going through a bunch of scans of old photos from my wife's side of the family and came across this interesting photo. It is from her Grandfather's vintage. He was a WW I veteran. I'm guessing that it is something sound-related and directional via the turntable that it is mounted on. I'm thinking it's an early attempt at quad-amplification!!

There were some systems designed to listen for aircraft. This might be one of those.

[Justice C. Bigler]

Or an alarm system. Looks like an early version of a tornado siren.

[Ivan Beaver]

There were some systems designed to listen for aircraft. This might be one of those.

There were a number of these types of systems in use by both sides for that purpose.

A horn can be used to capture sounds and naturally amplify them, just as when used with loudspeakers they can make the sound louder.

There are some photos of "ear phones" back in the 1860s and worn on the head with "small trumpets" that went into the ears for the hard of hearing.

[Mac Kerr]

I'm thinking it's an early attempt at quad-amplification!!

It's one of many passive listening stations for listening for aircraft.

Mac

[Lance Rectanus]

It's one of many passive listening stations for listening for aircraft.

I wonder how effective it was for hearing incoming planes, as opposed to having people in a tower with binoculars?

[Mac Kerr]

I wonder how effective it was for hearing incoming planes, as opposed to having people in a tower with binoculars?

In the dark, a lot more effective. They are also from a time before lots of motorized vehicles, when you could hear quite a lot on a quiet night. These stations are scattered all over the coasts of western Europe.

Mac

[Lance Rectanus]

Thanks, Mac.

[Jack Arnott]

There were some systems designed to listen for aircraft. This might be one of those.

Something I learned from Art is that once a horn goes beyond 12-18" with a straight side, it is no longer loading lower frequencies. So these horns would not be going below 350hz. (ish, IIRC)
 

[Jonathan Johnson]

Something I learned from Art is that once a horn goes beyond 12-18" with a straight side, it is no longer loading lower frequencies. So these horns would not be going below 350hz. (ish, IIRC)

Is there a reason that horns rather than, say, a parabolic reflector were used? Perhaps a parabolic reflector would have too narrow of a field of "view"? Or maybe their science wasn't quite up to par?

[ProSoundWeb Community]