Conn Speaker Pipes

Conn speaker pipes, first developed and patented around 1959 and marketed all through the next two decades until the Conn Organ Corporation went out of business in 1979, were a new invention to enrich the sound of the Conn electronic organ (patent held jointly by Conn Organ Corporation and Curt Wolfanger, a former Conn engineer).

They were well-received technology for the time period and, provided owners can find any of these units today, they still function to add subtle improvements to the sound not only the Conn organ but any electronic organ built c.1960-2000 having analog or early digital technology.
During their approximate two-decades (1959-1979) of development/production many thousands of these units were manufactured and shipped all across North America and the English speaking world; at the time they were not cheap to order but enjoyed significant popularity; they were in fact such a hot seller back in the day that production could not always keep up with orders; a few Conn dealerships were actually selling their display models about as fast as they were received, could never keep them in stock, and constantly had them on back-order.
These units were formed of a vertical array of cylindrical aluminum tubes of differing lengths and scaled diameters 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 are divided into two pair, 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 load on the amp with these multiple speaker units.

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 softening of attack and release and a subtle delay in the buildup and decay of sounds was also created.  This subtle "pipelike" delay with the onset and release of a key is something which can be heard but not counted.
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: The Pedal channel of an electronic organ should NOT be connected to Conn speaker pipes, as speaker damage can result.  It's also a good idea to further shield these units from any low end signal arriving from manual channels by connecting a small subwoofer between the amp and the speaker pipes with its low pass crossover knob set at its 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, 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.
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, with Right elevation.
Model 145, type 3, same, 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.

All 3 models were constructed in either gold or silver anodized pipes; the gold finish was more popular back in the day, and with fewer silver units in circulation they are more rare to find these days.
Each of the 6" X 9" oval Cletron speakers specially made for Conn for these pipe units had an impedance, or resistance, of 8 Ohms.  The 4 speakers supplied to pipe models 145 and 146 were wired in series parallel which put a "user-friendly" 8 Ohm load on the amp.  The model 144 pipe units having only one pair of speakers wired in series puts a 16 Ohm load on the amp and, when wired  parallel with another pair just like it, the amp is given an 8 Ohm load.
Conn speaker pipes were tuned in equal temperament to sympathetically resonate from about 200 Hz on up, which, when speaking of fundamentals or 1st harmonics, corresponds to tenor G# 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#) and the 145s all notes above middle G#.  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, weaker in intensity as pitch rises in accordance with the natural laws of musical sounds.
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.
Center elevation of pipes was offered only with the model 145, with right or left elevation offered with all three types.
Both types of 146s (right and left elevation) 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 real cylindrical metal organ pipes having labial mouths.
In terms of volume output these units are inefficient compared with the power needed to run them, this because the only place from which the sound from the speakers can be heard 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 which is not to enlarge the sound but to add subtleties -- dispersion, color, and speech effects -- with the instrument's other direct beam loudspeakers already providing sufficient dB gain and reproduction of bass frequencies to complete the organ sound.
Since each set of Conn pipes can be powered by as little as 20 watts, the console's own internal amp may be all that's needed to run just one set, but, if two or more sets are connected, then the need for a separate external amp is typically required.
There's something else very interesting about these units:  they not only resonate at fundamental primes but also at harmonics belonging to the harmonic series of lower notes.

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, 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.  Engineers also noted that the sound emitted was non-directional along with a very slight bit of reverb after the key was released as the sound within the pipes rapidly dissipated.
What this also means is, the 12 longest pipes of the model 146 not only resonate at fundamental primes of 8-foot pitch from middle G down to tenor G# but also resonate upper partial tones for any manual Doubles [of 16-foot pitch] sounding fundamentals an octave or more below.  While all notes in the manual compass are thus subject more or less to the action of these speaker pipes, a small subwoofer which shields these units from 16-foot manual strength coming from the amp is still a very good idea.
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.  As stated, 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 was a harmonically enriched wall of sound lacking the beam effect produced by ordinary cone speakers alone.  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 minute split of a second before dying away completely.  These effects are definitely audible -- they can be heard by the listener, but not counted (save by scientific instruments).
Again, these acoustical effects, while subtle, cannot be duplicated by direct beam loudspeakers or simply by adjusting the treble control of an amplifier.
These units can be connected to play through ANY make or model of analog or digital instrument and positioned to stand vertically or placed on a shelf horizontally, like real horizontal trumpet pipes, with the weight of the chests and their frame bracing making them stable enough to make this possible.  They have no input jacks and are connected to the amp using bare wire attached to the pair of screw terminals at the bottom of each pipe chest.  Each chest thus receives a single mono channel of audio.  These bare wires connections may be made more secure and complete by stripping the wires about 3/4" from the ends, attaching 1/8" spade connectors using a crimping tool, and tightening the screws around them.
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 a Conn or any other 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 is already powering the rest of the console's self-contained 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, to be 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 and possibly be ruined.  How many of these speaker pipe units are hooked up therefore makes all the difference in whether or not the amp driving them will survive.
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, and if the Ohm load is below the amp's minimum rating the amp can get fried and ruined.
Original Conn amplifiers are almost impossible to replace these days, as they went of of production long ago.  The solid state ones were not quite as particular about impedance as tube amps were, but, like all amplifiers, they were rated for a minimum 4 Ohm load.  As speakers are daisy-chained in parallel to one another the Ohm load always drops, so, one would never want to run a load that the amp is not rated to run at.  Again, the lower the Ohm load, the harder the amp has to work.

If the amp happens to have an 8 Ohm output jack, it is obviously a correct match for one of these Conn speaker pipe units.  If the amp's output jack is only 4 Ohms however, it would still be a safe mismatch, generally speaking, when connected to one of these 8 Ohm Conn speaker cabinets, provided that the amp is a good one and capable of maintaining a 4 Ohm load.     
When Conn pipes are clean inside and in the best condition one hears up close a certain something that wasn't there before -- a subtle brightness in and spatial dispersion of the sound -- but since these units are now well over 50 years old, and house dust, dead insects, pet hair, and other debris tend to accumulate on the upward facing speaker cones.  After coming into one's possession it's advisable for these units to be taken apart, cleaned and vacuumed, and checked.  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 Hobby Lobby or other retailers.  Unwanted finish that happens to get on the speaker box is easily removed using mineral spirits and paper towels.
The usual choice for those owners who have done extensive renovating of these units has been 6" X 9" oval car audio speakers from suppliers like Parts Express.  Again, if 8 Ohm rather than 4 Ohm replacements are used, the original Conn wiring may be retained.  If 4 Ohm replacement speakers are used having half the resistance of 8 Ohm speakers, they may be easier to power up to maximum output and twice as efficient, but they will be far easier to blow -- thus, it would be far safer, and necessary, to change the wiring to yield the original 8 Ohm resistance for the entire Conn pipe unit.    
NOTE:  at times one may have occasion to encounter 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.  Such 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 a Conn speaker pipe unit 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 best with analog and digitally sampled electronic instruments and that its effects tend to dissipate somewhat with distance.  Nevertheless it makes the diapason and flute stops sound a bit brighter, strings take on a finespun, discernable edge, reeds are keener, all voices sound as if they have more color and "breath," and full ensembles no longer cloy upon the ear, if they ever did, but can be listened to for long periods of time.
The general mistaken attitude prevalent today, looking backward in time at these units, is that they're aesthetic visual enhancements and nothing more, a reference only to the sight perspective but not to their audio effects.  While they have always been in limited supply, and today they are still very hard to find among private sellers, the model 145 is short enough to sit on top of the console, if desired, and it does look awesome there.

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).
Those who test this invention by swamping it in an avalanche of other direct beam loudspeaker sound, particularly with high treble boost, will have trouble hearing what they do and are prone to misjudge them.  But, the fact is, 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 energy and attention these days searching to locate and obtain these units if, after they were brought home and hooked up, they did nothing but look pretty.  A few owners who couldn't be more indifferent about visible appeal have even introduced them into their home stereo systems or connected them to their electric guitars for the "interesting effect" they produce in the sound.  This wouldn't be happening at all 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 according, and give them a fair hearing, the satisfaction they are certain to bring is not fake -- it's reality.

NOTE:  Six of these speaker pipe units [three 145s and three 146s] were tested in a home environment by connecting them to a large powered mixer which received output signal from the manual channels of a Viscount self-contained instrument built in the 1990's with digital sampling technology.  The sound was compared with the console's internal speaker system sounding with and without the pipe units turned on.  The difference was very noticeable.  The speaker pipes supplied improved realism and pneumatic and omni-directional effects impossible to reproduce with the mere addition of direct beam loudspeakers, amplifiers, and adjustment of treble controls.   

May. 12, 2016

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