Forum Top Banner Ad


Ebay Classic organs



No announcement yet.

Allen 505b Speaker Setup

This topic is closed.
  • Filter
  • Time
  • Show
Clear All
new posts

  • Allen 505b Speaker Setup

    Hi, my son's church has just acquired an Allen 505b organ with 4 HC12 speakers. Looking at the pictures he sent me I have no clue how to hook the speakers up. There are 8 sets of 4 wire cables coming out of the back or the organ that were clipped and taped.

    I see only two terminals used on the back of the speakers. (purple & black wires going into the speaker from the left terminal, blue and yellow going in from the middle which is the only other one with a screw to hook up a wire and a red and green on the right terminal with the screw removed per the instruction on the diagram on the back of the speaker.)

    I saw two terminal blocks that seemed identical in the back of the organ. Both had terminals marked "Main Spk 1" & "Ant Spk 1" with "Main spk 2" and "Ant spk 2" as well. White wires coming off the main speaker terminals, white and black coming off the antiphonal terminals. Other terminals were 12v; Main Relay; Ant Relay; Amp 1; & Amp 2.

    Do I have to run 4 wires to the speakers when there are only two contacts? To which terminal block should I hook up the speakers? We would like 2 mains and 2 antiphonals in the end.

    Thanks for your help (the Rodgers 760 we put in our church was so simple in this regard.)

  • #2

    You may wish to refer your son to a couple of threads on the Forum where the speaker setup for the 505B is discussed. Since you don't have any speakers to use for antiphonals, I would skip connecting anything to the antiphonal channels.

    The 505B has two computers (A & B computers), and 2 channels per computer (computer A has channels 1 & 2; computer B has channels 3 & 4). Most stops are duplicated on one channel from the A computer, and one channel on the B computer.

    Since you don't have antiphonal speakers, you can connect your wires directly from each S-100 amplifier (I assume) to each speaker. Wire one speaker to each amplifier. I just matched the black wire on the amp terminal screw to the black wire on the speaker. The white would be the other half of the wire with the black wire. Some of your cables may have a green wire with a red wire. If so, I connect the green wire to the black (or purple) terminal on the speaker, and the other end of the green wire to the black (or purple) terminal on the amplifier.

    The biggest issue with connecting the 505B is that you may have phase cancellation if you reverse the wires for a speaker. Forgive me if I'm insulting your intelligence with this explanation, but that means the woofer from one speaker is pushing outward while the woofer from the other speaker is pulling inward, and thereby canceling the bass totally. I had that happen with the 32' channel on my organ because someone had replaced the woofer, but wired it backwards internally.

    You can check the phase of a speaker by quickly holding a 9v battery to the two left terminals of the HC-12 speaker, and seeing if the woofer goes in or out. Test all 4 speakers to make sure the woofers all go the same direction. Make sure the positive terminal of the battery always contacts the same terminal of each HC-12--just like when you hook it up.

    You can check the photos of the amplifiers on the MOS-2 Reference thread at:

    The HC-12 terminals are hooked up to the 2 left terminals of the speaker. I thought I had a photo of those terminals, but I don't have them handy. The 3rd terminal (on the right) is used for a sub-woofer (not used in your organ).

    Hope this helps get you started.

    Way too many organs to list, but I do have 5 Allens:
    • MOS-2 Model 505-B / ADC-4300-DK / ADC-5400 / ADC-6000 (Symphony) / ADC-8000DKC
    • Lowrey Heritage (DSO-1)
    • 11 Pump Organs, 1 Pipe Organ & 7 Pianos