Allen AP-6 and B-40

[CarillonBells]

Hi everyone,

When I purchased my MDS-41-S, it came with two B-40s. Seeing as how I'm in a home, one should be more than enough as far as I can tell. I've received an inquiry from a church with a Protege AP-6 with four channels that is curious if their instrument would support such a cabinet, as it is in need of more bass reinforcement.

Was there any simple option on the Protege to add a subwoofer? I'm gathering that it would at least need some sort of crossover assembly.

Thanks!

[michaelhoddy]

You would need the crossover card that's in the larger organs that had a subwoofer options, or you'd need to provide a passive crossover of your own. Then it's the matter of putting that all on the speaker/amp channel that contains those stops.

Honestly, a B40 is massive overkill for an AP6, which if I'm thinking correctly doesn't even have a 16' Diapason, only the two 16' flutes in the pedal. A B20 would be plenty if you're just looking for some more presence in the bottom octave. The ubiquitous Allen bass boost card on the HC14/15 (assuming that's the speaker) might even be enough.

[jbird604]

I second what michaelhoddy says. There isn't much 16' tone to be had in the pedal of that one, but it might be possible to simply boost the Bass pot on channel 4 of the W5 generator to get a satisfying amount of pedal bass.

BTW, the W5 cage has a built-in subwoofer crossover, so an external circuit is not required. If you look at the faceplate, you'll see a column of output connectors on the right hand side. P948 is the sub-woofer output. The three pins on the right are the "LO" signal and could be sent into an amp and into a B40 or other sub. But as Michael says, that is probably not what this organ needs. It needs some voicing by a knowledgeable tech (or you).

[CarillonBells]

Thanks for weighing in - my first thought was voicing in need of a tweak - I couldn't recall if the larger Protege organs even had much of a lower octave presence. The manual confirms that there is only a Bourdon 16' and Lieblichgedackt 16'.

I checked with them, they're out in CA with limited budget. One of these days I still need to do some voicing my 41-S.

[Moller Artiste]

The ubiquitous Allen bass boost card on the HC14/15 (assuming that's the speaker) might even be enough.

Since you mentioned this, I had forgotten about the card on the back of the speaker cabinet. I have 14, HC-15s on my installation in addition to 2, B-40s. What does this adjustment do? Is the range of adjustment very noticeable? Thanks, Allen

[toodles]

The bass boost is properly a "Bass Lift" card, per Allen terminology. It is a circuit card contained within the organ (some models, not all)--it provides a slight increase in the bass drive volume prior to the amplifier. It was designed to make the bass performance of the HC-14/15 more closely match the HC-12; the 14/15 having a relatively flat bass response, and the 12 being bass heavy.

The card on the speaker cabinet is a crossover, and the adjustment on it (if present) controls the tweeter volume.

[Moller Artiste]

The bass boost is properly a "Bass Lift" card, per Allen terminology. It is a circuit card contained within the organ (some models, not all)--it provides a slight increase in the bass drive volume prior to the amplifier. It was designed to make the bass performance of the HC-14/15 more closely match the HC-12; the 14/15 having a relatively flat bass response, and the 12 being bass heavy.

The card on the speaker cabinet is a crossover, and the adjustment on it (if present) controls the tweeter volume.

All cabinets have the adjustment. Thanks for your help! Allen

[CarillonBells]

MOS Organ (301-B) and B-40?

I've been contacted now by someone with a 301-B instrument asking about the B-40 and their organ. They have a cabinet which they say has a 15" woofer and is labeled System 600 and "BASS" on it.

Can anyone tell me more about what might be going on, and if they could use the B-40 with that instrument?

[jbird604]

A System 600 is a two-computer two-manual, and it was typical to install it with one "bass" channel. This channel was actually crossed over from just one of the flute channels and served to boost the 32' and 16' pedal tone by giving it an extra channel.

I suppose a B-40 could be used with the 600 in place of the original bass speaker, which may have been rather undersized.