Multiple array speakers for electronic organs

[David Pinnegar]

Hi!

I'm wondering if anyone has experience of possibly older installations of electronics where arrays of some hundreds of speakers were used. I think I recall seeing photos somewhere of an instrument being converted to Hauptwerk where the original speakers were being discarded and they were panels of significant arrays of speakers possibly mounted as an open baffle.

The physics of these is interesting in attempting to create plane waves from the combined fronts of interference patterns but I'm wondering why they were used and in what circumstances and what advantages they were perceived to have had in the context in practice. They're not what would intuitively suggest themselves for suitability . . .

How did the bass survive if they were used as open baffles?

Best wishes

David P

[Colin Pykett]

Try this for size!

http://tibia.us/main/shaw_organ.htm

This is the Shaw Concept organ of the 1970's.  Although analogue, some of the extant recordings of it (and I believe Carlo Curley among others made some) sound extremely impressive by any standards.  I correspond with Neil Andrew Shaw from time to time.  IMHO he remains the only electronic organ builder who was valiant and brave enough to go commercial with enough speakers to overcome IM and signal mixing distortions.

Change is not necessarily the same thing as progress, and since then I know of no maker who has used the same approach.  Without enough speakers it doesn't matter a fig whether you are analogue or digital - it will still sound electronic.

Colin Pykett

[dragonser]

Hi,
I think this is a different setup but there seems to have been an Album recorded on a Rodgers organ with 94 speakers.
Album cover of the recording at http://www.pstos.org/recordings/baker/the-sound-of-94-speakers/cover-l.jpg

regards Peter B

[revtonynewnham]

Hi

It looks like the Shaw organ uses the speakers as separate units, not as arrays - so apart from the loss of bass due to leakage round the baffles (unless they were mounted with some sort of rear enclosure) there should be no problem.  David' comment is about arrays of speakers.  My experience of these is limited to the PA "column" or "line source" untis where the interference pattern is used to provide wide dispersion in the horizontal plane whilst limiting the vertical dispersion to reduce reflections from floor & ceiling in live rooms - exactly the same techniques as the modern "line arrays" that currently seem to be in "in" thing in live sound - although they are curved arrays a (a technique not unknown 50 years ago, but rarely implemented due to constructional complexity - the modern ones are separate boxes) and cover all but the extreme sub-bass frequency regions.  I would guess that similar effects can be worked through for arrays that have speakers grouped in multiples in each of 2 dimensions.  At the most basic, some guitar speaker cabinets use pairs or 4 speakers in a horizontal array.  Maybe some sort of directionality plot is available on line somewhere?

Every Blessing

Tony

[David Pinnegar]

Dear Colin

Thanks so much for your link to that incredible instrument - excitingly I think Keith Tomkinson might be persuaded to take up that idea in areas that he's developing.

Peter - thank you - it is probably the Rodgers units that I saw a picture of.

What I don't understand is why Rodgers would have used them. Large area moving mass for extra bass? Open baffle phase cancellation? Directivity - if directivity why would Rodgers want that for an instrument that's meant to fill the building? Why direct a beam, if that's the effect, in a particular direction unless it's at the west end aiming for an apse?

Best wishes

David P