Conn Speaker Pipes

The Conn Company's speaker pipes, first developed and patented around 1959 and marketed all through the next two decades until the Conn Organ division was sold to Kimball in 1980, were just one of a number of attempts to improve the early analog organ of the time by spreading and diffusing the sound.  Other solutions were Donald Leslie's two-speed (fast/slow) rotating speakers first used on Hammond organs, the Allen Company's variable speed Gyrophonic projector speakers, and the Compton Company's one-speed (slow) Rotofon speaker system used with its Electrone organs.  All of these work, but in different ways, to break up and disperse the sound.  All of them, being no longer made, are also rare finds these days, thus it's more usual to encounter instruments which have gone down the multiple speaker route and split the organ's output into different cabinets.

The Conn pipes bring out all voices save for the brighter reeds which improve with the use of additional tweeters.  There's no harm however in trying these pipe array speakers today and see what they do in the room where the organ speaks.  In each application their effects will be more or less noticeable.

These units were well-received technology for tihe time period, a rather hot item in fact for Conn dealers to keep in stock during the 1960's and almost always on back order with no unsold display model even in the store.  Many thousands of these sets were manufactured back in the day and shipped all across North America and the English speaking world.
This invention was formed of a vertical array of cylindrical anodized aluminum tubes of differing lengths and scaled diameters finished in either silver or gold and permanently tuned to resonate with various fundamental frequencies of the musical scale, like the bars of a marimba.  These were mounted vertically in single or double rows on a wooden baffle sitting atop a rectangular chest made of walnut wood inside of which either one or two pair of 6" X 9" midrange oval speakers were lined up end-to-end.  Each elliptical-shaped speaker was positioned under a plurality of pipes, screwed tightly to the underside of the baffle, and projected sound waves upward against it; the baffle in turn cushioned the sound as individual frequencies from held notes found their own pipes and caused them to sympathetically resonate.
NOTE: These units were wired in series parallel, meaning that the four 6" X 9" oval speakers of each unit mounted end to end were divided into pairs, each pair of which was wired in series and then both pair wired in parallel with each other.  Wiring each pair in series has the (-) side of speaker A connected to the (+) side of speaker B, and the same thing with speakers C and D, respectively.  These two pair were then wired in parallel by connecting the (+) side of speaker A to the (+) side of speaker C, and the (-) side of speaker B to the (-) side of speaker D.  Series parallel wiring is how the Conn engineers maintained a consistent 8 Ohm load on the amp using multiple speakers.

These units have no woofers, no tweeters, no crossovers, no additional circuitry.  With the speakers acting as motors to generate resonance, individual frequencies emitted by the speakers found their own pipes.  All of the frequency selection was done by the pipes.  The sound escaping vertically from the top of each pipe created a three-dimensional sourcing, the enhancement of the upper partial tones created an additional finespun but discernable brightening of color of individual voices, and a very rapid but measurable delay in the buildup and decay of sounds tending to soften their attack and release was noted by the engineers.
These were STRICTLY TREBLE AND UPPER MIDRANGE units and, in the case of the Conn organ, meant for connection only with the pulse channel manual voices (diapason, strings, reeds), NOT the Tibias, Vox Humana, or Pedal voices.
CAUTION NO. 1:  The Pedal channel output signal from ANY organ should NEVER be connected to these Conn pipes.  They ALWAYS should be shielded from low end signal arriving from manual channels by a) setting the amp's bass control at minimum level, b) looping the mixed manual signal through an equalizer and fully damping as much as possible all output frequencies below 200Hz, and/or c) connecting a small subwoofer between the amp and the speaker pipes and using its crossover network to protect the pipes by setting its cuttoff knob at highest position.
Some Conn organs were supplied with a 3-way toggle switch or perhaps dual toggle switches/rocker tablets for future additions, to select internal speakers, pipes, or both.
Conn speaker pipes came in 3 models and 7 different types or styles:

1. Model 144 "mini-pipes", type 2, Right elevation [determined by tallest pipe in back row], one pair of 6" X 9" oval 8 Ohm speakers wired in series, 16 Ohm load, 28 pipes in 2 rows of 14 each.
Model 144, type 3, same, with Left elevation [determined by tallest pipe in back row].
DImensions: 21.5" Wide, 8.25" Deep, 29-7/8" High, Wt. 17.5 lbs.

2. Model 145, type 1, Center elevation, two pair of 6" X 9" oval 8 Ohm speakers wired in series parallel, 8 Ohm load, 49 pipes in 2 rows, 28 front, 21 behind.
Model 145, type 2, same but with 48 pipes in 2 rows, with Right elevation.
Model 145, type 3, same with 48 pipes in 2 rows, with Left elevation.
Diimensions: 42.5" Wide, 8.25" Deep, 34" High, Wt. 18 lbs.

3. Model 146, type 2 , Right elevation, two pair of 6" X 9" oval 8 Ohm speakers wired in series parallel, 8 Ohm load, 12 pipes in single row.
Model 146, type 3, same, with Left elevation.
Dimensions: 42.5" Wide, 8.25" Deep, 63.5" High, Wt. 40 lbs.

The 6" X 9" oval Cletron speakers Conn used in these units each had an impedance, or resistance, of 8 Ohms.  As stated, the 4 speakers inside the 145s and 146s were wired in series parallel with a combined load of 8 Ohms.  The 144s with only 2 speakers inside were wired in series for a combined load of 16 Ohms.  This is important because the output jacks of any external amp used to drive them may specify 8 Ohms.
The pipes themselves were tuned in equal temperament to sympathetically resonate from 200Hz on up which corresponds to tenor G# on up with an 8-foot manual stop drawn.  The 146s were tuned to resonate fundamental frequencies for the lowest 12 chromatic semitones (tenor G# to middle G#) with the 145s covering all manual notes above that.  The combination of these two pipe units resulted in a continuous spectrum of resonances from tenor G# all the way to the top of the manual compass, naturally weaker in intensity as pitch rises in accordance with the natural laws of musical sounds.  In this sense the 144 "mini-pipes" offer no real advantage over the 145s save for not taking up quite as much space.
NOTE: an undue preponderance of tone is typically noted in the bass and tenor octaves of the ordinary 8-foot manual stop of a pipe organ.  Pipe ranks built in the ordinary way will thus display a decided tendency to weakness in their treble octaves.  The fact that grave sounds travel farther and have more fullness than acute ones is alone sufficient to account for the weakness in the treble of a pipe organ, especially when the instrument is in a vast building and commonly heard a considerable distance from its situation; this weakness can be overcome with increased wind pressures and/or skillful voicing and regulating in the treble octaves or, in some cases, simply by the introduction of properly balanced octave (4-foot) and higher harmonic-corroborating stops.  Conn speaker pipes function in a similar manner to augment the intensity of the harmonic upper partial tones of fundamental frequencies.
Both types (right and left elevation) of the 146s were constructed with cosmetic notches about a quarter of the way up the length of each pipe, all on the same side, this merely to enhance the visual perspective by simulating the appearance of the labial mouths of cylindrical open metal organ pipes.
In terms of volume output these units are obviously a bit inefficient compared with the power needed to run them, but that is not what they were built to do; the only place from which the sound from the speakers emerges is from the top of the pipes, their frequency range is limited, and by turning up treble volumes of other amps their effects are not as evident.  This results from their unique design and purpose for dispersion of the sound and color/speech effects, relying upon the other direct beam loudspeakers of the instrument for decibel (dB) gain and reproduction of bass frequencies to fill out the organ sound.
Since each set of Conn pipes can be powered by as little as 5 watts/speaker the console's own internal amp may be all that's needed to run just one set of 145s or 146s at 20 watts each (10 watts for the 144s), but, depending on the power of the console's internal amp, if several sets are hooked up a separate external amp is typically needed.

There's something else the Conn engineers observed when the pipes were tuned:  they not only resonate at fundamental primes but also at other harmonics of the harmonic series.  They had a demonstration of this where a small microphone was dropped inside given pipes.  This microphone was connected to a regular guitar amp, and they used a set of model 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.  They also found a measurable bit of reverb after the key was released as the sound very quickly but gradually died away.
While all lower pitches producable on the manuals are thus subject to the action of these speaker pipes, a subwoofer which shields the unit from 16-foot manual strength below 200Hz coming from the amp is still required.
Additionally, Conn engineers found that when the speakers were energized by held notes from the organ, the column of air in each pipe had to be put in motion before the sound could escape, resulting in the volume building up before the tone blossomed out the top of the pipes in all directions.  The pipes tuned to the harmonics of the same fundamental also would resonate.  The result of all this resonating and pneumatic action within the walls of the pipes is unique and unreproducable by any other means.  Additionally, when the keys were released, the column of air within the pipes would not come to rest immediately but would permit the tone to linger for a very minute split of a second before dying away completely.  These effects can be detected up close using a good ear, but not counted (save by scientific instruments) but cannot be duplicated merely by adding tweeters or adjusting treble controls.
These pipe arrays can be connected to play through ANY make or model of analog or digital instrument and can be used even with sample sets with good results.  They are built to stand vertically or placed on a shelf horizontally, like real horizontal trumpet pipes, with the weight of the speaker boxes and their frame bracing making them stable enough to make this possible.  They are designed to connect with the amp using standard 16-gauge speaker wire right off the spool.  Each box thus receives a single mono channel of audio.  These bare wires connections are made more secure by stripping the speaker wire at its ends, attaching 1/8" spade connectors using a crimping tool, and tightening the screws terminals under the pipe box around them.

CAUTION NO. 2:  The walnut speaker box is fairly sturdy but not waterproof or indestructible.  NEVER expose these units to water, excessive dampness, or give them rough treatment.

CAUTION NO. 3:  NEVER EVER, REPEAT NEVER ATTEMPT TO ALTER THESE UNITS FROM FACTORY DESIGN, such as by trying to shift wire connections from the bottom of the speaker box to the side, which would involve cutting wires loose from the screw terminals, drilling a new hole somewhere in the side, rerouting the internal parallel speaker wiring to the outside through that hole, and then resoldering and/or making a wire splice to reestablish connections ... all guaranteed to create a potential weak link in the incoming signal stream, make the external wiring more difficult to protect and hide, and destroy the unit's resale value.

CAUTION NO. 4:  On all models and types of Conn pipes the pair of screw terminals where the speaker wires connect are UNDER the box out of sight and project about 1/8 inch from the surface.  To protect from damage and to keep the unit stable when it sits on a wood floor or other hard surface the bottom four corners of each box are supplied with a rubber foot 1/4 inch tall set about 8 inches in from each end.  If the box happens to sit upon a carpeted suface the entire weight of the unit gets compressed on these four small feel causing the unit to sink completely into the carpet with its bottom, screw terminals and all, missing any free way space.  If the unit is to be moved it should be picked up bodily and set straight down.  NEVER slide these units on a carpeted surface, as this can bend the spade connectors pressed into the carpet and likely break one or both wire connections, rendering the unit silent.  
Conn made a special add-on control box to provide easy switching between the console speakers and the pipes, but these kits are very hard to find these days -- one is extremely fortunate to simply have acquired one or more sets of pipes.
Hooking up these pipe units to any electronic organ today presents a consideration of critical importance called impedance -- the resistance offered by the circuit to the transmission of an electrical current.
Every amplifier connected to a speaker system is rated for a minimum impedance load (in Ohms).  In Conn organs the simplest way to attach these pipes was to hook them up in parallel with the main pulse channel for the diapasons/strings/reeds and have them powered by the console's internal amplifier; it's important to understand however that connecting a set of Conn pipes in parallel like this reduces the impedance load to the console's internal amp which could already be powering the rest of the speaker system.
NOTE: When 2 resistances (impedances) are connected in series, they total.  For example, a pair of 4 Ohm speakers wired in series results in an 8 Ohm load to the amp (4 + 4 = 8 Ohms).  When 2 resistances are paralleled however, a formula comes into play for calculating the impedance.  The total impedance in parallel is the multiplication of the two loads divided by the sum of the two loads.  For example, a pair of 8 Ohm speakers wired in parallel results in a 4 Ohm load to the amp (8 x 8 = 64, divided by 8 + 8 = 16, which is 64/16 = 4 Ohms).  It's the same result as totalling the loads in reciprocal, whereby 1/8 + 1/8 = 2/8 = 1/4 = 4 Ohms.

Since the minimum impedance rating of most amps is 4 Ohms, it's plain to see that connecting several of these 8 Ohm speaker pipe units in parallel can make the amp work harder and, if the circuit's impedance is below the amp's minimum Ohm rating, the amp will heat up.  How the speakers are wired therefore makes all the difference in whether or not the amp driving them will continue to operate.
According to Ohm's Law the voltage in the circuit is the product of the current (in amps) and the impedance (in Ohms), and, since the wall socket voltage remains constant, whenever speaker units are paralleled the impedance load is reduced and the current in the circuit increases.  This, again, as stated, makes the amp run hotter than it's supposed to.
Original Conn amplifiers, being out of production for many years, are almost impossible to replace these days.  The solid state ones were not quite as particular about impedance as tube amps were, but they all were rated for a minimum 4 Ohm load.  As speakers are daisy-chained in parallel to one another the Ohm load always drops, so, it's never a good idea to try to run a load below that.  Again, with constant voltage arriving from the electrical toggle, low Ohms in the circuit translates into more current, thus, the lower the Ohm load, the hotter the amp will run.  If the equipment has protection circuitry and heat becomes a problem, the amp will shut off at heavy volumes, but the result is still the same:  no sound.     
Over time house dust, pet hair, and even dead insects and other debris falling into the tops of the pipes tends to accumulate on the upward facing speaker cones.  It's advisable in the beginning for these pre-owned units to be taken apart, cleaned and vacuumed, and checked prior to hook-up.  The original pipe finish may be restored using a tube of metallic gold leaf or metallic silver leaf Rub 'n Buff applied with a cotton ball and available from craft retailers.  Unwanted finish that happens to get on the speaker box is easily removed using mineral spirits and paper towels.
The usual choice for replacement of the Cletron speakers, if needed, has been new 6" X 9" oval car audio speakers.  If 8 Ohm replacements are used which are easily available, then the original Conn series-parallel wiring may and should be retained CAUTION:  if replacement speakers rated below 8 Ohms are substituted with no change in wiring the resistance the whole pipe box presents to the amp drops drastically.  For example, if 4 Ohm replacements are used [4 x 4 = 16, divided by 4 + 4 = 8, which is 16/8 = 2 Ohms] it will have the amp operating below its minimum inpedance unless the wiring is also changed.  All that rewiring work can be eliminated simply by using replacements rated at 8 Ohms.

NOTE:  on very rare occasions one may encounter the owner of a custom-built pipe speaker unit constructed of wood and conventional PVC [polyvinyl chloride] pipe tubing created to be used with, and extend the lower compass of, Conn speaker pipes.  These oversize units have been built in both rectangular and square styles,  The square style typically consists of a large, sturdy, hollow, square-shaped wooden box inside of which is mounted a single 12" woofer which projects sound upward through a large, circular opening and through a wire screen baffle to the entire plurality of pipes (usually 12) mounted above it.  Above this baffle would be positioned on end 12 general purpose [3-1/4 inch diameter] PVC pipes of varying lengths.  Iin this style the pipes are bundled tightly together, usually spray painted a metallic gold or silver leaf color to match, and cut to proper lengths to resonate sympathetically at fundamentals from 8-foot tenor A down to 8-foot bass A or thereabouts, and at higher harmonics of notes below that.  Since these pipes are all of the same diameter their positions over the speaker cone has much to do with their lengths because the air inside them vibrates at different velocities depending upon how much sound each of them receives.  Those clustered over the center of the speaker face receive the most sound while those situated to the outside occlude only the edge of the speaker cone.  This explains how two different pipes of identical diameter in these units which are tuned to resonate at neighboring chromatic semitone pitches could be very close if not equal in length.  It is not unusual for custom built, one-of-a-kind units like this to stand something over 7 feet high and overlap the tuning of the bottom two semitones [tenor A and G#] of the model 146 Conn pipes in order to continue the chromatic scale downward from the Conn pipes with no audible break.
What's important to understand about Conn pipes is that this invention, the way it disperses sound within the room, the gradual buildup and gradual decay of sound associated with it, and its efficiency compared with the power needed to run it, is old technology meant to work with conventional speakers and that its effects are most noticeable up close; if it is used all by itself the effect may be disappointing, but it was never intended to work that way.  Up very close it makes the diapason and flute stops sound a slight bit brighter, strings take on a faint but finespun, discernable edge, reeds are a slight bit keener, the sound gets dispersed throughout the room to where it seems to come from every corner, adding to the depth and ambience of what the listener gets to hear.
The general mistaken attitude prevalent today, looking backward in time at these units, is that they are merely aesthetic visual enhancements, a reference only to the sight perspective and not to their audio and pneumatic effects.

Pricing of them today seems to be all over the place and is mostly dependent upon their condition.
Again, these are treble and midrange units where the sound never gets out of the wooden base -- it all emerges at the tops of the pipes pointed at the ceiling (in the case of the model 146, a small portion of the sound also emerges about a quarter of the way up the pipes at the cosmetic notches).
Part of the reason certain owners fail to be impressed with this invention is that they test it by swamping it in an avalanche of other loudspeaker sound with high treble boost to where the ear cannot hear them.  The treble portion of the signal being sent to the pipes is best kept FLAT with the treble of the other speakers turned way down to allow the pipes to shine through and carry most of the treble for the whole organ.  It's easy to be fooled when the pipes are tested against ordinary loudspeakers pushed to the limits like this and nothing more seems to be reaching the ear.  Informed musicians from all over the country would not be spending, in some cases, hundreds of hours, traveling hundreds of miles, and spending hundreds of dollars plus a good deal of time, attention, and elbow grease searching to locate and obtain these units if, after they were hooked up, they did nothing but look pretty.  A few owners who couldn't be more indifferent about decoration have even introduced them into their home stereo systems or connected them to their electric guitars for their subtle harmonic effects and the way they spread and diffuse the sound through the room.

NOTE:  A reliable source, upon discovering and fixing a broken wire connection to ONE of the model 145s he had hooked up to his own digital practice organ, even though the instrument was already speaking through 2 other sets of 145s, 4 sets of 146s, and dozens of other loudspeakers of various sizes, he had to go back and reset ensemble combos stored on piston memory to compensate for getting this one lone set of 145s working again.  It made that much difference in the mid- and upper midrange resonance of individual manual voices to require some readjustments in the buildup to full organ.    There would have been no need for this, if window dressing was all these units had to offer. 
If the user knows how to take them apart, clean them, reassemble them, hook them up, test them, adjust amplifiers accordingly, and give them a fair hearing, the satisfaction they are certain to bring is not fake.

It's reality.

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