HC18 Allen Speakers

[John Vanderlee]

I mentioned the ADC4500 in my previous post. It was connected to HC18 speakers which I had never seen before now. Were these a special item? Did they have an exclusive function? They use a JBL 15" driver.

[toodles]

It was an upgraded version of the HC14/15 to my knowledge, using more expensive drivers. It probably was very high efficiency, as that is a hallmark of JBL Pro drivers. I know they were more expensive. I think they were just high end, general purpose, high efficiency, good quality broad-band speaker systems.

[jbird604]

I think Allen may have been trying to offer a system that could overcome some limitations of the HC-15. The -18, with its hefty JBL woofer, was quite capable of handling 32' pedal stops, including the challenging Contre Bourdon, which the HC-15 simply wasn't up to. It also had a larger midrange cone of some kind, presumably so the crossover from woofer to mid could be at a lower frequency, again to benefit the very low bass. I think the system overall was somewhat more efficient too, which made it generally more useful when the organ went into a larger space, make it less necessary to double up the cabinets or use additional amplification.

The Achilles Heel of the -18 was the foam in the surrounds of the JBL woofers, which rotted out just like the foam in HC-12 woofers and so many other drivers we all know about. Once rotted, the cones were as useless and the sound as raucous as the cheapest, and replacing them with the same drivers would be outrageously expensive, I imagine. Thus, whatever advantages they offered were short-lived, unless a diligent tech or dealer would take on the task of re-foaming the cones.

At any rate, I didn't see a great many organs installed with these, for whatever reasons. It seems that Allen went back to the HC-15 for general use, and soon introduced the HR-200, which was proclaimed to be "twice as nice" as the HC-15. I was told by a dealer that it would no longer be necessary to double speaker cabinets, since the HR-200 was "equivalent" to two HC-15's. I don't know what the data behind that would be... Of course the HR cabinets are more efficient than any HC models, and the drivers are probably pricier, though there are only two per cabinet instead of three. The HR-200's long-throw horn turned out to be a double-edged sword though, as it projected the "highs" way out there, as designed, but left the near-field somewhat dull. Thus the addition of the "colander" attachment.

[you795a]

The HC-18 was a combination of a HC14 and HC-9. Inside of the cabinet there is a particle board divider that was installed in a slanted position. They made them for a few years. They were made in utility and finishes cabinets.

[toodles]

One advantage to using JBL drivers are that the surrounds for them are readily available.

[John Vanderlee]

That explains a few things. The theater has a few HR 200's as well set up, and a number of HC18 with bad surrounds in storage.
I figured out the mess was set up originally with 2 channels with too many speakers on them. We're redoing the set-up with 4 amplifier channels allowing use of 8 cabinets, plus a separate bass channel (see my post about reconfiguring the pre-amp, elsewhere).

I guess I'm going to be busy re-foaming JBL drivers.

[John Vanderlee]

RE: JBIrd's comment on HR 200 drivers being pricier.
Not really. The 15" is the same accordion type used in the HC series. And the horn driver can be had for about $40. The horn itself I have seen as low as $8.00. The crossover of course is proprietary Allen, but I 'll bet it can be analyzed to be replicated.
Now that makes me curious if that speaker design is copyright protected?

[myorgan]

Now that makes me curious if that speaker design is copyright protected?

Knowing Allen, almost certainly.

Michael

[jbird604]

I agree that the components in the HR-200 aren't necessarily expensive. That selenium horn is plastic and is very cheap from various sources, though the driver is a premium one and the woofer is certainly a premium one, probably by Eminence. I'd think the crossover schematic is copyright protected, as is all Allen literature, but it has relatively few parts and could certainly be replicated for not too much money. The Allen engineers probably designed it using standard crossover design tables, with certain tailoring components chosen "by ear" to produce a specific type of tone coloration they wanted.

[John Vanderlee]

I guess the cost of drivers is on the high side, relatively speaking. I mean they are certainly not bargain basement speakers. But I find the cost not overwhelming like the JBL drivers for instance.
Woofer: http://www.eminence.com/speakers/spe...el=Kappa_15LFA
Driver: https://www.parts-express.com/seleni...-8-18--264-270
Horn:https://www.parts-express.com/seleni...8-tpi--264-315

[toodles]

Here is a chart that gives the crossover designs that Allen used in various models, including the HC-18. Note that if you are replacing any of the inductors--chokes, as Allen calls them, you should match the resistance, as it has an effect on the crossover.

If you use substitute drivers you may find the crossover design needs some adjustment, as any crossover design will work differently when different drivers are used. In other words, for substitute parts, these values would be a starting point. Note that C4-C5-C6-C7 network form an infra-bass filter to prevent excessive cone exursion to protect the woofer.

Universal Crossover.pdf

[CarillonBells]

I guess the cost of drivers is on the high side, relatively speaking. I mean they are certainly not bargain basement speakers. But I find the cost not overwhelming like the JBL drivers for instance.
Woofer: http://www.eminence.com/speakers/spe...el=Kappa_15LFA
Driver: https://www.parts-express.com/seleni...-8-18--264-270
Horn:https://www.parts-express.com/seleni...8-tpi--264-315

The dealer in my area swears by using the HR-200 to replace older Allen speakers, saying they improve the sound of the instrument. I know they go for a pretty penny from what I was told, as I know someone who purchased them with an instrument upgrade (ADC era instrument). Woodworking isn't my forté, but at the price for those drivers and to build a crossover one could come in with some serious savings, especially after selling off existing speakers! Out of curiosity, are those actually the drivers Allen is using, or some that are fairly close is specification?

I've always been rather curious whether my MDS-41S would sound better with the newer speakers.

[jbird604]

The components linked by John Vanderlee above are indeed the exact ones used in the HR-200. Adding in the cost of high-quality inductors and capacitors for the crossover, the raw cost of the parts would probably be between $200 and $250. A rule of thumb is that an assembled speaker cabinet usually carries a retail price around 5 times the total cost of the piece parts, so a retail price for the HR-200 of $1000 to $1200 is probably about right, in line with the way commercial and audiophile speaker builders price their goods. That sounds high, but you gotta consider the very large amount of labor that goes into building a fine speaker system. It's far more than just a simple wooden box with the parts screwed in.

[John Vanderlee]

Absolutely what Jbird says. We have built cabinets and it takes at least half a day for one.

[CarillonBells]

No doubt, given the construction quality I would expect that it isn't a fast process. Plus they have to pay the labor, make profit, and have margin for the dealer's profit as well. Out of curiosity, is there a modern equivalent for the HE speakers? My organ has the relay boards to run one, but the speaker didn't come with it. Are there any technical drawings for the new designs, or just for the older ones?

[jbird604]

Corey,

I "think" the HE speaker is still in production and used on Festival Trumpet channels only, for which it was designed. I know that there are HE cabinets on some fairly modern Renaissance organs here. I can't honestly say if the very latest installations use one though. They may have retired it in favor of just using the excellent HR-200.

It's not a "hi-fi" speaker at all, and in fact probably has a very pronounced mid-range peak. From the looks of it on the outside, it's just a rather stiff-coned 15" driver and two stiff paper-cone 3" tweeters. More like a "guitar" speaker cabinet than an organ speaker! I'd venture to guess that the crossover is VERY rudimentary. May not even have an inductor on the 15" driver, just a capacitor to cross over to the tweeters, which obviously require protection from the bass frequencies.

This may sound ridiculous, but I know of one Allen installation where instead of an HE cabinet, the Festival Trumpet relay brings in a big ugly PA horn in parallel with the HC-15 on that channel. I'm sure it's a "rigged" setup, not that way from the factory, but it actually sounds awesome. It honks just like you'd want a Festival Trumpet to do, and is VERY loud.

I'd assume you could use a typical high-efficiency outdoor type PA horn, such as those used in train stations and other places where announcements are made and need to be heard in a large open space. The one on the organ I speak of is sort of beige colored and about 16" x 9" (best I recall) and maybe a foot or so deep. You should get one that is 8 ohms, and wire it so that the HC-15 doesn't get turned off when the relay is thrown. You just want to bring in the extra "honk" but not totally eliminate the body provided by the HC-15.

I'm not sure, but the horn may have a capacitor in series with it to keep the bass out. Probably about 30 to 60 mfd would do. In most Allen setups, the Festival Trumpet relay is only active when the Festival Trumpet stop is selected BY ITSELF on whatever division it resides in. When any other stop is drawn, the relay opens and the channel goes into the regular speaker. This is to keep the rest of the stops from ever being heard through the HE, as they would sound pretty awful through it.

[CarillonBells]

John, Thanks for the commentary on the HE cabinet - I had suspected they had been phased out, but it appears they still have a purpose at least as of somewhat recently. I could see a PA speaker working decently for that purpose, maybe I'll have to try that at some point. Someone messed with the relays at one point, but I do have three UNIVREL boards in the console (two for antiphonals). The festival trumpet is fairly honky but I would imagine it would really stand out with the extra speaker. I know that as soon as any other stop is drawn, the stop changes to a Kleine Trumpet if I recall correctly.

All this talk make me even more curious about how things would sound with some HR-200's hooked up.

[John Vanderlee]

Our "road Organ" GW319EX Allen has 12 HR 200's with it. We found that because of the horn directionality we face them against a wall if possible. It smoothes the "pinpoint" right out and actually gives nicer ensemble.

[CarillonBells]

That makes sense - if I had an appropriate amount of space for my speakers, I would have the sound reflect and add some spatial presence to it. I've seen this done when there is an actual chamber vs a cutout for the sound to speak. Did the GW319EX come with those speakers? I'm curious to hear from anyone who has done a side-by-side comparison on the same instrument with the older and newer model speakers.

[John Vanderlee]

It came from a home with a different speaker setup. Four HR200 and 2 HE speakers. Because this organ "travels" it is easier to deal with 6 HR200's only. For larger venues we use 12 HR200. The bass channel is carried by 2 SVS powered subs.