May. 12, 2016

Conn Speaker Pipes

Conn speaker pipes were a product of the Conn Organ division of C.G. Conn, Ltd. and were built from the mid-1960's to the early 1970's to improve the sound of the electronic organs of the time.
These units were a very hot seller back in the day and difficult for Conn dealers to keep in stock; they consisted of a rectangular wooden chest supporting a factory-tuned array of cylindrical metal pipe tubes of different lengths and diameters, below which were mounted inside the chest and end-to-end from two to four 6 X 9 inch oval speakers which directed sound waves upward through the bottom of the pipes (photo) and projected the sound in the same direction.
In the case of the Conn organ, these speaker pipes worked only on the main voices (diapason, strings, reeds), and a separate speaker of some kind would be required for the flutes (tibias) and pedal.
The sound from these speaker pipes, which were all wired the same way, excited the column of air in the pipes which were calculated to sympathetically resonate at certain frequencies, the idea being that the various frequencies generated inside the chest would find their own pipes; in addition, it was found that the higher harmonics or upper partial tones of a given note were somewhat strengthened.
Conn engineers had a demonstration of this where a small microphone could be dropped inside any given pipe; this microphone was connected to a regular guitar amp; they used a set of 145 pipes labeled as to their tuned pitch.
While holding down middle "C" on the organ, the microphone would be lowered into ANY "C" pipe, and a "C" was heard coming from the guitar amp; then, while still holding middle "C", the microphone would be lowered into a "G" pipe, and one would hear a "G" [3rd harmonic, or 2nd upper partial tone] coming from the amp, and likewise with an "E" pipe, an "E" [5th harmonic, or 4th upper partial tone] would be heard coming from the amp; the sound emitted also tended to be non-directional; engineers also noted a very slight bit of sustain, or reverb, after the key was released as the sound within the pipes quickly dissipated.
These units, while designed by Conn engineers, could be connected to play through ANY make or type of electronic organ; they were untunable however and were found to work only with frequencies from about 200Hz (i.e. 8-foot tenor G) on up.
These speaker pipes could be positioned to stand vertically or placed on a shelf horizontally, like real en chamade pipes, with the weight of the chests making them stable enough for the pipes not to require supporting bracing.
Some owners today, if they can find a set of them, appreciate having them if for no other reason to have an array of dummy facade pipes for their visual effect; pricing of them these days seems to be all over the place due to their scarcity, and a lot depends upon their condition, as it seems they're easily damaged and not very amenable to shipping given their shape.
To be perfectly honest, in a residence situation strategic placement of other speakers will be found more satisfying at amplifying the frequency spectrum and distributing the sound about the room.