Splitting Great/Pedal Channel on a ADC

[Hamman]

So on my Allen ADC 5300 I have since took up an interest in splitting one of my channels which is labeled Great/Pedal. However, when I studied the Voicing cage sheet that came with my organ, I noticed something that doesn't seem right. It seems that the only Great divisional stops that are conjoined to the certain pedal stops are of the Articulation effect only. The actual stops "shared", great stops themselves, have their own channel...per se. Yet those "articulation" effects of those stops that are shared with the GT/Pdl channel are shared with the 32' pedal....not the 16' ,8', 4' pedal channel.....as I would have thought. This doesn't make sense to me. Being that if the great "articulation" is shared with the 32' pedal stops then I would have to conclude that I would need a speaker that has to have upper frequency response as well....like that of my HC 12 currently wired to this channel. That would also mean that I could not just wire that channel to a B40 without losing that articulation effect?? What am I missing here?


Update:
Stranger yet is that audio channels 1 and 6 labeled from the cage audio out is what goes to my bass lift card. :-P

[toodles]

I think the articulation generator only has 2 outputs, and thus some of the articulation is sent to a different channel than the voice it provides articulation for. Allen probably did not thing it important enough to provide a separate articulation generator for each channel, since in churches the speakers are usually quite a distance from the listeners and the effect would not be noticeable, and in a home setting speakers are usually fairly close together so the different sound location would not be very noticeable.

Myorgan mentioned this in his posts about converting his ADC-4300 to a 6-channel installation.

As to the bass lift, this is normally added to channels with 16' stops, but not reeds, using HC15 speakers, and not on 32' voice channels. HC12's were supposed to be used for 32' voices, unless split out with the subwoofer crossover. Perhaps the ADC-5300 designer felt with the 2 pedal 16 reeds the fundamental needed a bit more "oomph" in the bottom octave. Does the organ split the 32.

Does your organ have a subwoofer output? It would normally be placed in between your channel 1 before the amps, and then there would be a separate subwoofer amp--in essence, you'd have a 7 channel organ. Your descriptions make me think the audio was changed after it left the factory--i.e., subwoofer added, different speakers used, etc.

[Hamman]

Toodles, I don't know if the bass lift card is considered a subwoofer split of sorts. Channels 6 (great) and channels 1, a mix of great (mostly articulation) and pedal both come from the cage audio out and feed the "Bass Lift" card. From there the 32' and great articulation proceed to channel one of the pedal amp which is labeled "Pedal" The other output on that Bass Lift board is labeled 6A and goes to channel 2 of the pedal amp labeled as GT/Pdl. I have another amp labeled swell 3 and 4 and another amp labeled Great 5 and 6. Yet just by looking at all the wiring and ties you can tell nothing has been jerry rigged or monkeyed with.
You know, pondering on this a bit more, I think I may be confusing bass lift with dedicated subwoofer channel? It appears after staring at the above guide for a while, that the reason they "mix" channel 6 into the the bass lift card, is, it is really a mixer of sorts (?). Another member here who also has a 5300 does have a true factory 7 channel organ with a dedicated subwoofer channel. Can anyone here confirm or deny my thoughts on this? I'm going to have to rethink this endeavor..........

[toodles]

Here's a nice photo that Myorgan posted on the thread regarding his mods to his ADC-4300. It may help you.

Yes, you are confusing bass lift with a separate subwoofer output.

Bass Lift is NOT the same thing as the Subwoofer crossover. The Bass Lift is a tone-control that increases the bass response a little; it exists because when the HC-15's came out the bass was relatively flat in response, but many customers wanted a little fatter bass. The bass lift cards come in a few varieties with a different number of channels.

The bass lift card is not a mixer--it keeps each of its channels separate. Channel 6 goes to it probably to fatten up the bass end of the Quintaten 16 on the Great.

The Subwoofer crossover is entirely different: it takes the pedal output channel with the 32' stops, and separates it into 2 different outputs. One goes to a B20,B40, or one of the more modern subwoofers, and it carries probably just a few octaves of fundamentals--I haven't measure it to determine where it crosses over. The upper octaves go through and onto the normal amp with HC15; the lower octaves, to the subwoofer.

Adding it to an ADC-4300 makes it a 5-channel organ (4.1 in home theatre parlance); to an ADC-5300, would make it a 7 channel organ, unless it already has separate channels for brass choir, etc. then it might be 8 or 9 channels?

In the picture, the upper card is a 2-channel bass lift card: 2 inputs, 2 outputs. Only one channel is used in the photo. The lower card is a mixer, possibly USRM. Looks like 4 channels in, and 1 out (to the reverb) and one back from the reverb. The card on the right is the subwoofer crossover. It only has 3 audio connections: in, low out, and high out.

If you do NOT have a dedicated subwoofer channel, then the 32' channel should have an HC12 instead of an HC15 speaker. Otherwise you'd get NO 32' octave of sound, just the harmonics thereof. Check the speaker chart on the bottom of the voicing sheet.

I've only seen the subwoofer crossover mounted on the backside (inner side) of the swing out panel. But other locations are possible.

I'm not sure what your intent is, but in the ADC-5300 the Great and Pedal are already separated as much as possible. The articulation can't be separated further and except for that, the great and pedal are completely separated.

[jbird604]

Hamman,

A bass lift card and a subbass crossover card are two different devices. According to the Allen tech site, your 5300 should have bass lift only on channels 2 and 6, as these two channels must have some 16' stops in them. There should not be a bass lift on channel 1, as that is the channel with the 32' stops and an HC-12 speaker (or optionally one HC-15 and a B-40 with crossover and its own amp)

If you have a little circuit board with channel 1 going into it and two channels coming out, then it must be a bass crossover. In that case, your organ would have to have seven amp channels and seven speakers.

Post photos of all the boards involved and maybe we can tell what you have. It could be that someone has tried to wire in a crossover, or perhaps the wires have gotten mixed up.

[myorgan]

Hamman,

I'm with John and Toodles. From the posts you have made, and the channel guide you pictured below, it appears your channels are already split as much as possible--with only one exception. You don't have a sub-woofer crossover (the card on the right in my photo). The top card is the Bass Lift card, and the white-colored card is the card where the Great and Pedal channels were mixed from 4 discrete channels (from the cage) into 2 combined channels (USEM card--NOT a USRM card).

I'm glad Toodles posted the photo of my cards. It reminded me of this thread where I contemplated the channel split for what seems like forever. Now that it's completed, I really need to post the updated photos!

Hamman, many of the question you are having now are addressed directly in the thread I linked in the previous paragraph. Meanwhile, I hope to update the thread I linked with more recent photos. However, I won't be near the organ again until mid-July when I return home. Someone please remind me then.

Meanwhile, Hamman, that thread may answer many of your questions. I think I bypassed the USEM-1 card completely and did all the voicing on the cards in the cage, but I won't remember for sure until I see the organ in person.

I hope this is helpful.

Michael

P.S. Hamman, make sure the Channel 1 speaker is as near the other speakers the articulation affects (Channels 4 & one other, I believe). That way they will be perceived to belong to the stop. That becomes even more important in a smaller room (like in a home).
P.P.S. I believe I kept the Great channel formerly coupled with the Pedal, attached to the Bass Lift because it needed the boost to sound properly through an HC-15, compared to an HC-12. You have 2 channels available, so it's up to your tastes.

[Hamman]

Thank you so much John, Toodles and Michael!! This all makes sense now:embarrassed:. So unless I add a active crossover to the bass pedal channel I really can't use a B40 in place of the HC12 that I am currently using. Also the explanation of "what and why" on the bass lift card is an enormous gain in knowledge for me! The light bulb is fully lit now :-> I will take pics of what I have and post. However, I have not removed or moved any channels so if you see something amiss....it wasn't me :-P lol.
Again you guys are a tremendous asset to this forum and I am greatly appreciative of all your help!
I am going add the crossover for the subwoofer and that will be it for additional channels going forth. My B40 should be here early next week (so the truck driver told me) and I want to have every thing ready. I'm thinking of setting the crossover at 80 or 100hz. If anyone has a better known frequency please chime in:-)

[Hamman]

Here are some pics. I did the best to describe "to/from" John you are correct in your above comment referring to designated channel assignment. I do have additional card(s) that are the "Trem" cards that take in audio outputs 3 and 4 (swell) from the cage and go into these Trem cards. Respectively they come out of the Trem. cards and feed the Swell amp as 3A and 4A


My biggest assumption that got me into "wrong thinking" here was that the "Bass Lift" card actually "lifted" the bass....another way of Allen saying subwoofer crossover......boy I'm tired now:o

Hmmmm I labeled all the pics but for some reason it doesn't come up when you click on a pic. Yet you can go to my gallery of pics for my 5300 and it shows the description there

[toodles]

It does "lift" the bass--using "lift" as to cause it to rise, but not "lift" as in "steal"!

If you use the Allen Subwoofer crossover, the frequency is fixed.

[myorgan]

It does "lift" the bass--using "lift" as to cause it to rise, but not "lift" as in "steal"!

PU--Two thirds of a PUn!:devil:

If you use the Allen Subwoofer crossover, the frequency is fixed.

Hamman,

In addition, you will need to add a single amplifier, or replace one of your ADC Dual Amplifiers with an ADC Triple Amplifier (3 knobs instead of 2), so you have an independent amplifier audio control for the sub-bass channel (your 7th channel with the B-40). Keep your eyes out on eBay and other sources, because they occasionally show up--that's where I got mine. John and others can advise you concerning whether or not an AM-100 or S-100 can be used for that channel. Something makes me feel it can be done, but I don't remember for sure--something about the expression circuit, if I remember right.

Just in case it occurs to you, the sub-bass crossover should NOT be added after the audio is amplified. It needs to be inserted BEFORE the audio is amplified. Beyond that, I can't think of anything else.

Michael

P.S. Your photos were great, and answered a lot of questions.

[jbird604]

Yep, your photos clarify it all. You have a standard-issue six-channel setup. The "bass lift" inserted into the audio path on channels 2 and 6 are there because these channels both have one or more 16' stops present and they go into an HC-15 speaker. Allen believed that the HC-15 speaker was a little deficient in low bass, so they always added this bass lift (which simply boosts a certain narrow range of low frequencies) to channels with 16' stops that feed HC-15s. In the older days, when all the channels used HC-12s, there was no bass boost, because the HC-12 has plenty of bass output. the HC-12 is so good at doing bass they continued to use it well into the Renaissance era as the speaker of choice for any channel having a 32' pedal stop.

Now...... as to adding a crossover, another amp, and a B-40. Are you sure you need it and want to go to all that trouble? Channel 1 in your organ does carry a wide spectrum of stops, all the way from the 32' contre bourdon up through the pedal mixture, and also the "articulation" of certain great stops. So it might sound marginally better with the super low frequencies separated out and directed into your B-40, leaving the existing full-range speaker to do the rest.

But it's a rather involved project. Before you even think about it, are you certain that you have the HC-12 hooked up to channel 1? If you've accidentally connected an HC-15 to that channel, you certainly won't be getting much 32' bass out of it. If you're sure you have an HC-12 on that channel and you're not satisfied with the bass, the simplest thing to do is to add a second HC-12 in parallel with the first one. The existing amp can easily drive a pair of them, and you will get twice the bass, as well as improved dispersion of the highs.

But if you really want to add the B-40, you'll need an additional amplifier (or swap the 2-channel for a 3-channel), plus the Allen sub-bass crossover board, the power supply cable, misc stuff like RCA cables and speaker cabling. The fanning strip on your present two-channel amp has blank lugs for connecting a third speaker, so you'll have to solder your B-40 wires to those lugs, unless you just use an outboard single-channel amp. But an outboard amp would add its own problems, such as how you are going to mute the amp to prevent turn-on and turn-off pops and bangs.

I've done it a couple of times, and it's not as hard as it might sound, but I'm not sure it will do you as much good as you think. Your HC-12 is capable of putting out earth-shaking bass all the way down to the 32' range, and you might get just as much satisfaction by optimizing its placement (near a corner) or by adjusting the bass controls on the TG boards that produce the 32' stops.

Just my 2 cents worth.

[Hamman]

Michael and John...thanks for your input/advice. I do know that adding a "sub-woofer" split would indeed require a active crossover and additional amp channel. Once again I may have gotten way ahead of my self by already obtaining a B40 ( going on 2 months ago)...yet not received. I decided to go this route when I was clearly under "wrong thinking" about the workings of my "bass lift" card. (I mistakenly thought of it as a sub woofer cross over). So now with a "clearer thinking" on how my system works, John I do agree with you that adding another HC-12 to my setup would be the way to go....plus it will balance out my speaker set-up. Wrongly Reading my VD&C chart it did baffle me that most of the Great, along with the Pedal, articulation went to that HC-12....However I see the clearer picture now. I still may incorporate that B40 at some time. Maybe at around 80hz and below

[jbird604]

Good plan, I think. While the B-40 and crossover make a HUGE difference in a church, where the speakers need to pump a whole lot of air to create believable low bass, in a smaller room the difference would be negligible. You'd have to run the B-40 at a very low level to keep from blowing out your windows!

If you can get another HC-12, just be sure to test the phasing of the woofers. A simple way is to use a battery (a 9 volt battery works well) and a couple of clip leads. Clip lead the negative terminal of the battery to the common terminal of the speaker cabinet. Then attach a second clip lead to the "+" terminal of the speaker and gently "tap" the positive terminal of the battery, observing the cone motion. If the speaker is wired in "normal" phase, the cone will move outward when the clip lead touches the battery terminal. If it is wired "backwards" the cone will suck inward. (Note, don't leave the second lead in contact with the positive terminal for more than a brief moment at a time, as it will send quite a bit of current though the voice coil and could damage it if left connected for an extended amount of time. You only need to tap it for a half a second to observe the cone movement.)

I believe HC-12 speakers have their woofers wired "backwards" and the cone will move inward. But when replacing cones, people have been known to get it wrong, so make sure that both of your HC-12's are properly wired.

If you test an HC-15 speaker using the same method, you will find that the cone moves outward on a positive pulse, indicating that the woofer is wired in the "normal" polarity. (A side note -- later production HC-15s have a capacitor inserted into the signal path ahead of the woofer to keep the ultra low frequencies out. this capacitor will also prevent the battery test from working, so you can't really observe the cone motion in that case, unless you temporarily short out the capacitor.)

It is this polarity difference that makes mixing HC-12 and HC-15 speakers a little sketchy. Allen says "do not mix different type speakers on the same channel" and doing so will result in strange phase effects, even if you reverse the polarity on the HC-12 terminals, because the crossover points are all different. No problem with using different type speakers on the same organ, as long as they are not on the same channel. (Adding the little PP speakers to any channel does not cause problems, as they do not produce any bass.)

Best policy -- use the speakers your organ was designed for. Of course I am the world's worst to disregard that rule. I even have a pair of Rodgers speakers on the swell channels of my Allen at church, and a pair of Rodgers subs on the pedals! (I do have HC-15s on the great...) But it has not been easy getting all these diverse units to work together.

[don60]

Adding a second HC-12 will not produce the perception of "twice as much bass."

Adding the second cabinet will indeed roughly double the acoustical power being produced, but this doubling is scarcely perceptible to the listener (because the human ear responds logarithmically to changes in loudness). A factor of 10 increase in acoutical power is needed to create a perceived doubling in loudness.

[Hamman]

The second HC 12 is not going to be used for the "doubling" of bass.....i.e. 32', yet will be wired in with the other HC 12 for anything and everything above the active crossovers (point) I will be implementing. I will be adding my B-40 (finally arrived today) along with its amp, that will take everything from 80z and below from the active crossover, to the system. My system is doubled so the HC 12 should be as well now that I will be adding the B-40

Adding a second HC-12 will not produce the perception of "twice as much bass."

Adding the second cabinet will indeed roughly double the acoustical power being produced, but this doubling is scarcely perceptible to the listener (because the human ear responds logarithmically to changes in loudness). A factor of 10 increase in acoutical power is needed to create a perceived doubling in loudness.