Adding speakers to Rodgers 705 Kent

[Savagedl]

My wife was recently asked to play the organ in our church services. Not an organist, but a pianist, she has been spending extensive time at our church practicing and learning how to play with some level of quality. (I think she is doing a great job.) This then got us looking for a used full sized organ that she could use at home to practice. After scouring the countryside, (craig's list) we came across a free Rodgers 705 Kent in really nice shape and brought it home.

Unfortunately, the organization that we got it from didn't want to take down the matching speakers from the walls. So we are in need of speakers. I am new to organs and don't understand how the speaker systems works and the wire connections.

I am interested in learning what types of speakers would work and how we would set them up. The organ has what appears to be an internal amp and has speaker wire connections as shown in the attached photos. If there is a organ primer somewhere I could access, that would be helpful as well.

Thank you.

[toodles]

The 705 does have internal amplifiers. There is a technical manual for the 705 on eBay here: https://www.--------/itm/Rodgers-Org...IMAAOSwFSNcCiW ~

I only recommend getting the manual if you are familiar with electronics. Also, make sure you have a model 705 and not a 705B, as the service info will be a little different.

If I remember right, the 705 needs 3 speakers; one is a subwoofer, and two are full range. This would work if your are anywhere near Cathedral City CA. http://barton.theatreorgans.com/selectedad.asp?ID=24125

If you want people to help you find stuff on this forum, add a location to your profile--it helps us know where to look for stuff for you.

[Savagedl]

Thank you for your direction. I do have a 705B, and do have the early service manual. However, not being overly familiar with electronics, it is pretty much Greek to me. My guess was that with six speaker connection points, this would relate to three speakers, one being a subwoofer. Any ideas on which leads would be to the subwoofer channel?

I am in Wilmington, Delaware, close to surrounding states of Pennsylvania, New Jersey and Maryland and can travel fairly easily to these locations to find speakers. We picked up the organ in rural PA north of Lancaster.

[jbird604]

The white wire (which you can see is looped to three of the terminals) is the "common" wire that should go to the negative or "C" terminal of a speaker cabinet. The green, orange, and purple wires are the "+" wires for the three speakers. I seem to recall that the purple one is the bass channel.

As toodles says, you need two more or less full-range speakers and one subwoofer. The full-range speakers built into a small Rodgers console like that one were actually nothing more than a 6" midrange and an attached tweeter, but when the speakers were wall-mounted they might have been Rodgers M10's, which have some 6x9" cones plus some small tweeters. So some smallish but good-quality speakers would do for those two channels in a home setup.

The bass channel would have been connected to a Rodgers "P16" cabinet, which had two 12" high-compliance woofers in parallel. Actually, any decent PASSIVE subwoofer would be fine. I have seen them priced under $100 on some internet sites such as newark.com where they are sold to pros installing sound systems. Sub cabinets that cheap are not premium quality, but for organ pedal tones in a home setting they are certainly adequate. Note that you don't need a "powered" sub of the kind often sold for home theater setups.

[Eric Mack]

John, please define "high-compliance subwoofers" for me. I see that term used often

[Eric Mack]

It never occurred to me to look to newark.com for speakers. I see they have an 18" speaker in box, claiming 20Hz-500Hz for $75. https://www.newark.com/mcm-custom-au...9?st=subwoofer

[jbird604]

Yes, they do have some really cheap subwoofers. The cabinets may be thin, but for home use they ought to be just fine. A "high compliance" woofer is one with a very soft ring of foam or rubber around the edge of the cone so the cone can move in and out quite freely. This type of driver must be mounted in a box that is of the right size and design to keep the cone from moving TOO far when a low-frequency signal is applied. Otherwise it may rip itself right out of the frame. They are sometimes used in tightly sealed boxes, but also in vented boxes with carefully calculated port dimensions. These drivers do allow you to get bass down to a lower frequency in a smaller box than the stiffer cone surrounds, but the stiff-suspended cones are probably easier to work with, as the box design is not as crucial for controlling the excursion.

[John Vanderlee]

If you have trouble finding Allen HC12 and HC 14, PM me. I'm in the Hudson Valley 1.5 hrs north NYC.
John

[toodles]

As JBird indicated, the violet wire is for the bass channel.