Speakers on Allen MOS-1 model 100 or 120

[Scout]

Our church has this Allen organ and near as I can tell it is a MOS-1 type model 100 or 120. It is in a very tight corner of our small balcony. The speakers built in face toward the organist. Problem is that she gets a direct blast of all the sound but a half height balcony wall traps most of the sound from getting out and down to the main floor level. There was talk of whether the internal speakers could be housed in some other type of enclosure and then placed somewhere maybe still near the organ but in a position to "send" or aim the sound out and down. I don't know about using the built in speakers due the amount of effort to build an appropriate enclosure.
Then, not knowing much at all about organ speakers, is there some sort of speaker system on the market (all in one box) or are they called tone boxes, that could be connected in place of the existing ones and again aimed to do the job. The way it is, the organist can't hear the congregation sing with all the organ sound coming right to her and so is difficult to know if you are playing loud enough or not loud enough.
I'm an electronic tech by trade so I think with help I could get it hooked up correctly. Again, any advise and help will be much appreciated.

[AllenAnalog]

Rather than removing speakers from the organ and building a custom box for them you should just buy two high quality full-range speakers with multiple drivers and hook them up to the output of the two amplifiers in the console, disconnecting the wires going to the internal speakers. It's a simple job. You could find used Allen HC12 speakers online but you might have to replace the surrounds on the drivers if they have foam rot.

[Scout]

Did a search for HC12 but only one set on Ebay and freight would be$300. I don't have a schematic of the organ / speaker connections. When you say 2 amplifiers.... Is there a separate amp for the low end and then for the midrange, hi end? Anyway if I can locate some good vintage stereo floor speakers should I get a pair and put one at each back corner to project out? Anyway how would I be connecting two either 4 or 8 ohm units to the organ output? Thanks!

[AllenAnalog]

A MOS-1 single computer organ like yours has two audio channels. Each channel has an individual amplifier, which is screwed to the bottom of the inside of the console. There are two screw terminals for the speaker output on the amp, which will have wires leading to the internal speakers driven by each amp. Disconnect those and hook up individual 2-conductor cables to power your external speakers. For short distances, 16-gauge wire is fine.

An 8-ohm full range speaker with a decent size woofer is the best choice, one for each channel. I wouldn't put the speakers too far apart since the voices of the organ stops are split between the two channels. It would probably sound odd if you put one in each corner and they are more than a few feet away from each other.

Try your local Craigslist along with ebay. HC speakers come up for sale or auction all the time but not always close enough to make it worth the drive to pick them up since they weigh about 85 pounds.

[myorgan]

Larry,

Would HC-14 or HC-15 speakers work OK on his organ? Since the organ doesn't have 32' stops, I would think the HC-14 or HC-15 speakers would serve the church's needs well, and the highs would be a bit more reinforced. I wouldn't support using stereo speakers because many of them do not have the ability to handle low frequencies for extended lengths of time. I recommend Allen's speakers.

Scout,

I second Larry's great advice above. As John (jbird604) related in another thread, it was not uncommon practice to move the internal speakers from an Allen, and placing them on a board outside the organ behind grille cloth. Personally, I prefer Larry's advice of purchasing 2 external speakers and using them.

Michael

[Organkeys Jones]

HC-14 or HC-15's would actually sound better than HC-12's on that organ.

[Scout]

Thanks for the information. I mentioned trying Ebay but usually the party will be far enough away that the freight would shoot the deal down. I'm in a small rural town so no Craig's list town nearby. I found some possibilities in Minneapolis Craig's list but that's over 2 hours away. So will keep checking around. Do you think having the speakers about 4-6 feet apart would be adequate? Guess I'm pretty ignorant on how they separate the sound to produce different "voices" from the organ or whatever that is. When mounted internally, the speakers are all within inches of each other so seems like it would all come out "together" anyway so why have two separate audio outputs... couldn't they just use some sort of crossover setup. Thanks again for you help AllenAnalog !

[myorgan]

If there is no need to separate the speakers, you should leave them together. Often, people will recommend angling the speakers so the sound reflects off a hard wall, slanted ceiling, or even off the back wall of the balcony. Just a thought.

Michael

[AllenAnalog]

By "voices" I mean the sounds that come out of the organ when you depress a stop tab and then play notes on a keyboard. Each stop tab represents one voice and it will come out of either the Main or Flute channel, not both. Each channel has a full-range frequency output; there is no bass channel or treble channel. The speakers for each channel have crossovers built into the console but they are part of the speaker wiring and most probably visible on the board which holds the internal speakers.

I would look for any Allen HC-x speakers, just get a matching pair of the same model number and be sure to look at the surrounds on the speaker cones to make sure they are in good condition. These speakers have their own crossover networks for the various drivers.

Once you have external speakers connected you will have to experiment with their placement to find the optimum place for the organist to hear as well as getting the sound out to the congregation better. So have a few extra feet of speaker cable for each run to allow changes in placement until you are satisfied.

Each amplifier has a volume control and they are used to change the maximum output level of the organ and balance the sound between the two channels. Any external speaker you use will have a different efficiency than the internal speakers so once the organist uses the swell pedal (the foot operated volume control) to show you how loud the organ can sound with maximum movement of the swell pedal and full chords, you can adjust the amplifier volume controls accordingly.

[Scout]

Thanks Larry for your explanation... helps a lot. Also thanks "myorgan" for your comments. I've tried but can't seem to get the quote function to do what I want. Have tried highlighting with my cursor the sentence I want to quote. Then click on the quote symbol. The word quote appears with brackets which is where I would expect the highlighted words to appear. When I go to preview the quoted lines don't show up so don't know what I'm doing wrong. Anyway that's a side issue. I want to address your comments here maybe numbered so I can be sure I'm clear.

1. As far as getting 2 speakers for this organ to mount externally, I have some questions. If it just isn't possible to find any of those Allen models you suggested, would it still be acceptable to use a pair of high quality stereo speakers with about a 12" woofer, a midrange and tweeter? Even if I locate a pair of Allen, I'm concerned about buying them and then finding the surrounds are falling apart. (By the way is this true just of the woofer or all the speakers in the Allen units?) I don't feel capable of trying to repair these especially if paying a sizable amount for them only to find they need to be repaired. Wondering how that is such a common problem (faulty surrounds) if our 1973 organ seems to have no such problem.

Seems I was browsing through some other posts and recall a fellow saying he knew of a person in Wisconsin that rebuilt some Allen speakers and I was wondering if he may be able to locate and sell some he has serviced. The name of the fellow was not mentioned for privacy reasons but the poster said a PM from anyone would be all that would be needed to put one in touch with the Wisconsin fellow...… BUT I can't find that post and any attempts of doing a search never works for me.... guess I don't know just how to approach the "search" feature as to whether you want to search the entire forum site or just one topic. So if anyone can help me come up with a discussion where a town in Wisconsin is mentioned, maybe it would give me a lead to contact that fellow to see if he has some Allen speakers or knows where to locate them. Since I'm in Minnesota, shipping may be lower being adjacent states.

2 I've included 2 photos here but the space on each uploaded photo where you can write something about it doesn't work for me. I put in a description of the picture but when previewing, the description doesn't show up.

In the pictures you will see an overall shot of the small church where you can see the balcony and on far right is where the organ sets. Another picture is a closer up view of the tiny space the organ is located. The picture of the balcony may help you fellows suggest where the two external speakers might be placed. There was talk about placing them fairly close together so that would mean either side of the center wreath? Another option might be near the far sides of the balcony but then would that create that issue of folks not getting the full sound of both with that kind of separation? Obviously we also want things to look symmetrical. Would not like the speakers right against each other and don't want them to stand out like a sore thumb.

I will stop at this point as I've mentioned maybe too many things already..... thanks again to all.

[myorgan]

What nice architecture! The arched ceiling can cause acoustical anomalies as well. The church where I grew up had an arched ceiling, and I remember them having to take some time overcoming some acoustical anomalies. I've included a photo.

It appears your church is small enough there are a couple of options:

1. Run the speaker cords along the ceiling trim, and mount the speakers in the front of the church facing the balcony. The church doesn't appear to be large enough so there would be a delay. The only issue is that perhaps you'd hear the organ more than the voices-facing the other way.
2. Place both speakers opposite the organ, but angled either toward the ceiling, or toward the center of the balcony. Not enough so the sound is directly facing the organist, but enough so the organist can hear a good mix between the organ and the voices.

Most of the surround issues lie with the 15" woofer on the Allen organs. The HC-14 & HC-15 speakers used accordion surrounds which were paper-based, and were not subject to disintegrating surrounds. The HC-12 speakers were the only ones which had foam surrounds subjected to disintegration. The 4" mid-range speakers of all 3 were subject to disintegration, but the surrounds can be replaced. John (jbird604) wrote a post about it a couple of years ago, and related his experiences with the project. Hiring someone to replace surrounds isn't really expensive-it just takes time.

Hope that helps.

Michael

[Scout]

Well I'm back to dealing with the idea of placing two replacement speakers for the Allen organ in/at the balcony. I've included a photo of the church with the balcony shown. The organ is in a little nook on the right side (from this viewpoint). At present all speakers face towards the organist's legs and then further preventing most direct sound is the balcony half wall itself. Just reviewing reason for considering the idea of disconnecting the internal speakers and run cable to two external speakers. Still not sure about placement. Having them up front near altar would drown out the congregation. Still the most practical placement would be at right and left side of balcony just in the front of it at the corners of outside wall and balcony wall.

I've included two photos of what I think must be the two amplifier output terminals. I see the word "Output COM" for each amp. So that would be the neutral line and the screw terminal just next to it would be the signal or positive terminal for the channel. Do I have it correct... disconnect wire leads from speakers at each of these two amps and then connect my external speakers in their place??? Thanks guys for your valued input... P.S. You may note the word "Flute" on the sticker on one of the amps.... missing "Main" on other one.

[jbird604]

Yes, you have it right about the terminal markings. Disconnect the internals and add the externals at that point, making sure to observe polarity at both ends of both cables.

What you're doing will probably help, since the current setup with internals only surely isn't getting much organ sound out into the pews. But keep in mind that the organist still needs to hear the organ perfectly. Can the speakers be located so that they project sound from somewhere behind the organist, shooting it out toward the people? That would allow the organist to hear everything clearly, and still send out lots of sound to the pews.

Don't forget that bouncing the organ sound off a hard surface is often a good idea. Organ sound is not the same as PA system sound (which needs to shoot directly at the ears of the listeners). Organ tones are greatly prettied up when the tone rolls around in the room, reflecting off hard surfaces, picking up subtle delays and echoes. So it could actually turn out to be best to throw the organ sound toward the rear wall of the balcony, up as high as possible, and let it reflect from there, passing through the area of the console on its way to the nave.

Also keep in mind that the two channels of the organ produce radically different tones. One is the flute/pedal channel, and all the sounds coming from it are perceived as "mellow" -- bassy and lacking high overtones. The other channel, called the "main" channel, carries those rich, crisp, brilliant string, reed, diapason, and mixture tones. In order to enjoy the organ properly, each person in the room needs to hear a balance and a blend of the two channels.

How to do that? Best is to have the two speakers fairly close together and directing their outputs in the same direction. If both speakers, for example, throw their sound at that rear wall, the sound will then be heard by the listeners as a smooth blend of the two channels. OTOH, if the speakers are 20 feet apart and blowing straight out at the crowd, the tones will sound weirdly separate and unpleasant to most people.

[Scout]

Great comments, jbird604 ! If anyone else has a suggestion on speaker (2) placement please join in.
After church today I took a few photos to show what I have to deal with. Also if you jump back and see the previous post of mine with the amplifiers, you will see the one pic viewing the balcony from the main floor level to get an overall perspective. On this post I'm including a poor sketch of the floor layout of the balcony. The dimensions are just from mental estimation but you can see the tight spot the organ has and the very limited seating in the balcony. If you see the stairwell, beside it is a wall and directly across from there is a facing wall of similar size.

Now if you see the view from the very back looking toward the altar, that space nearest the camera is rarely occupied. On this view and maybe another, if you look very closely, you may see 4 small metal brackets lagged into ceiling. I believe before the present organ, these hangers held one large speaker box.

My thoughts are (1) hang two speakers side by side from these brackets. How far apart and how far forward and facing which direction? (the speakers would be housing a 12"
woofer in each plus midrange and high range speakers. Only other thought (2) mount the speakers up high on the two facing walls at the top of the stairwell. Then which way to angle them. Should they be facing the opposing wall and get some "bounce" that way … same thought on first idea... should they just sorta both shoot at an inward angle out over the balcony rail sort of toward the outside walls.

Your suggestions will be much appreciated. Thanks very much.

[Scout]

OH... just an after thought. Maybe the best placement would be to the forward (towards altar) of the two opposing walls and up near ceiling. Again in second picture that shows those metal ceiling brackets, I'm referring to the two facing walls (one with the stairway and the other with a louvered vent). Then going in direction of altar, place them near ceiling and face them either crisscrossing or at the sanctuary left and right walls for "bounce". Thanks for listening.

[jbird604]

Looks like any reasonable placement would work. If you mount them up high, the sound will benefit from reflections off the ceiling, and will also carry further. So I'd suggest that you try that first. BTW, it might be best to mount the two cabinets together rather than spreading them apart.

I know that's counter-intuitive, since we think of "stereo spread" when we see a pair of speakers, and have the idea that spacing them rather widely will improve coverage. But re-read what I said above. The two speakers produce radically different sound, and to enjoy the organ tone each listener needs to hear a BLEND of the two channels, not one or the other, not a stereo image, not one louder than the other. So it won't hurt at all to simply place both of them at ceiling level, side by side, facing out toward the nave, shooting over the player as he/she sits on the organ bench. This should allow both the player and the congregation to hear a decent blend.

[myorgan]

Scout,

That "back room" area in the balcony could act as quite a sound trap if you aim the speakers toward the back. I think, perhaps, that rules out backward mounting of the speakers. I think very little sound would escape that area unscathed.

My first recommendation would be to place the 2 speakers at the rear entrance to the "hallway" created by the walls of the balcony, facing forward. I'm thinking that if they are each placed:

• On opposite sites,
• At an approximate 45Ëš angle,
• At ceiling level,
• Facing forward toward the opposite wall, and
• Canted toward the ceiling,

You might get a good blend that will then carry along the ceiling of the auditorium. I think using this method will allow the output from both speakers to mix without phase cancellation, yet it will allow the organist to hear the ouput without being overwhelmed, and thereby providing a better blend of sound with the congregation. Of course, there are several other options, but I think this might be the first one I'd try.

The 2^nd option would be to mount both speakers in the same location as described above, but both on one side, beside each other at an approximate 45Ëš angle toward the opposite wall. That may not provide as balanced sound, but it will be blended and non-directional to the listener's ear.

Please let us know how it turns out.

Michael

P.S. For both setups, the piano can be moved if the sound is too much for them. Perhaps back-to-back with the organ, or opposite the organ in the balcony where the wall will serve as a shield from the sound.

[Scout]

Thanks for the great suggestions. I've made another sketch trying to illustrate what I think you mean by your descriptions of possible locations. Each of the three circled and lettered "A", "B" and "C" are what I think you had in mind. I'm assuming the middle walls are the two you had In mind. The one labeled 6' in this and previous sketch.... First with "A" at the further back spot on each wall. Then "B" more forward on same wall and last, labeled "C" where the two speakers would be hung from the ceiling very close together and near center.

As suggested I would have them at about 45 degrees to the wall in A and B and facing in direction of opposite wall. Similar in "C" center area, near ceiling with speakers shooting at outside walls and crossing each other. In all cases they could be slightly canted toward ceiling for more 'bounce'

My 2 choices would be with the speakers forward (toward nave) on the side walls or the one with speakers close together at ceiling level as indicated.

Hopefully my descriptions and depiction are clear and as your suggestions describe. If there are corrections or additions needed let me know.. thanks for now!

[jbird604]

"B" looks good to me. "C" as well. "A" looks less good, as the sound might tend to get lost back in that area, though it would have the advantage of possibly blending moire and getting a little more bounced around.

[myorgan]

I'm with John, but would go in alphabetical order-A, B, or C as a last resort. Another possible option would be to mount one A speaker on the wall, and then one B speaker on the same wall, both set to reflect off the wall opposite both speakers on the same wall. The reflection off the opposite wall would cause the two to blend in that space, and then proceed out from there-granted at an angle.

John has much more experience than I do, so the A option might get caught in the back like he says, but I'm of the opinion that most of the sound from the speakers will be directional, so I'm not sure how much of the sound will get trapped behind the speakers. Just my 2¢ worth.

Michael