Rodgers 950B speakers

[Guest]

Hi Everyone — We’ve discovered that our speaker cones on our speakers have begun to deteriorate. We have a Rodgers 950B, probably installed in the 1990’s. Seems the cones were made of a paper composite-like material and they’re now showing their age. In order to recone the speaker, do we have to use Rodgers parts or can we swap out the old cones with new speaker cones of the same wattage, frequency, etc.?

I don’t “speak” speakers so I’m at a complete loss when it comes to these matters. Thanks for your help!

[myorgan]

Historyguy,

Re-coning a speaker has been discussed ad infinitum on the Forum. Generally, paper did not break down as you describe, but rubber surrounds did. Perhaps the speakers have that composition? As an Allen guy, I can't be sure.

That said, however, it sounds like the speakers should be re-coned. If all other parts of the speaker are OK, you should be able to find surrounds to replace the former surrounds, depending on the driver. Your speakers should be OK as long as too much power was not put through them when the speaker did not have intact surrounds.

Others who will be able to help you better are JBird604 and toodles. To that end, I am moving your thread to the Electronic Organ Repair forum where you will find more views.

Michael

[myorgan]

Here are some links to possibly helpful posts/threads:

• https://www.organforum.com/forums/sh...l=1#post438988
• https://www.organforum.com/forums/sh...l=1#post443404

To your original question, I would comment that I rarely hear of Rodgers' factory-installed speakers needing to be repaired. However, it is a common occurrence for Allen's early HC-series speakers. That fact alone makes me wonder if the issue you're experiencing is what you're describing.

Do you have a way of recording what you're hearing or photographing exactly what's wrong with the speakers and posting it? If you click on the "Go Advanced" button at the bottom of the post reply window (where you type your post), you can manage attachments there (photos & recordings).

Welcome to the Forum, and I know you'll find help here.

Michael

[Historyguy101]

Hi Michael—
Thanks for the response and links to previous posts. Someone had posted this picture in one of the previous posts:
https://www.organforum.com/forums/at...0&d=1487555845

Our speakers aren’t that bad, but same idea. The edges of the speaker cones are coming detached. When I’m at the church this week I’ll try to get a picture of exactly what I’m talking about. Thanks.

Ron

[toodles]

The central part of the speaker is called the "dome" and it is there for cosmetic reasons and to keep dust out of the voice coil. The one shown in the photo you referenced is caved in, but that by itself is no cause for concern. The outer edge of the speaker which is flexible and permits the speaker cone to move in and out is called the "surround" and the ones in the photo have deteriorated. The deterioration is caused by a fungus that attacks certain materials, and early foam often shows this problem. When they figured out that it was caused by a fungus, manufacturers started adding a fungicide to the material, so newer foam materials are not as prone to this kind of deterioration.

The "cone" is the conical shaped part of the speaker, and rarely deteriorates to require replacement unless it is heavily torn or suffers from water damage if it is paper. Replacing this part is called "reconing". It is probably best done by professionals and often it is easier to just replace the entire speaker unless the speaker is a very expensive one. If you replace the speaker it is best to get the same speaker as Rodgers used, probably directly from Rodgers.

The surrounds on speakers can be replaced quite successfully but it requires careful work. This is called "replacing the surround" (to be technical about it) and is not nearly as critical as replacing the cone. You can purchase kits to do this yourself or have a speaker repair professional do this. To do it yourself, you heed to be "handy"--i.e., not "all thumbs".

If you post pictures of the speakers you have showing the damage, the folks here will be able to assess the damage for you and offer suggestions.

[jbird604]

A Rodgers installed in the 90's would most likely have foam surrounds on all woofer cones. We just don't talk about them a whole lot on this forum, as Rodgers owners are greatly outnumbered by Allen owners here. The speaker in the pic you shared is a common Rodgers cabinet called FR1.7. The woofer is an 8" 8 ohm unit which Rodgers sourced, I think, from Peerless, so quite nice. Purists may like to have them re-foamed to preserve whatever magical qualities they were supposed to have, but here's a nice brand new one from Newark.com that is quite a perfect replacement, and not very expensive:

https://www.newark.com/mcm-audio-sel...audio%20select

The only adaptation you'll have to make is to use snips to clip the "ears" of the terminals on the speaker so the narrow push-on connectors will slide on.

The bass cabinets may also need new drivers, as some of them were built with 15" foam-surround drivers, which will have rotted by now. You can use the commonly-available re-foam kit for 15" cones, if you are willing to repair them. Newark used to have very reasonably priced 8 ohm 15" rubber-surround woofers (around $30 each), but they have disappeared from the website. You might find another source for good quality 15" woofers that can handle about 200 watts. A rubber surround is preferable, to help the woofer get down into the 32' octave, though the large ported box does a good job of getting extended bass out of any good quality woofer.

[Historyguy101]

Hi Everyone—Thanks for the responses. Here are some pictures of the damaged woofer drivers (they’re all FR 1.7 speakers). All six FR speakers are in a similar state. Should we have the damaged surround rounds repaired or just buy new woofer drivers? Wondering which option would be more cost effective...? Thanks for your help!

[jbird604]

Those look pretty bad to me! They have been rotten for a very long time, and there's a chance the voice coils have been rubbing in the gap, which could alter their electrical characteristics in a bad way.

You can buy six new ones of the type I mentioned above for under $100 plus shipping. I think that's a tiny investment to keep an organ playing that would cost $150,000 to replace! As I said up above, some people do re-foam them to "keep them original" or something, but I think it's risky when they are as blown as those look to be. Just get some new ones. It isn't hard to replace them. Just remove the four screws, pull each one out, observe the polarity (which color wire goes to the + terminal), and install the new ones with the same polarity. You may have to nibble the terminal ears to get the small push-on connectors to snap on, but that only takes a couple seconds with diagonal cutters.

Be sure to check the 15" drivers in the subs while you're at it. If you're lucky they will be rubber and will not have rotted out. but they could be foam, and if so, will need to be replaced or re-foamed.

[Historyguy101]

Thanks, jbird604, for the response. I did check the large subwoofer speakers and thankfully they’re fine! I agree that the drivers should just be replaced however I am concerned about sound quality. Will the drivers we buy online have the same sound quality as the ones from Rodgers?

[toodles]

My calculations show that the replacement driver that JBird suggested will have an increased response in the bass range from 60 Hz of about 3.5 dB returning to normal response at around 200 Hz--that's not a huge hump, but it will be there. It also means response below 60 Hz will taper off faster than the original driver. Essentially it is giving up the bottom half octave response of the speaker system.

Is that critical? That depends upon what voices and pitches are routed through the speakers. The driver is low enough in cost that you could buy one and try it out before you decided to do all of the speakers that way.

This driver is closer in specifications to the original, and performs better in that size cabinet, and is about $25: https://www.parts-express.com/dayton...oofer--295-310

To get the exact same performance as the original driver, it would be best to have your drivers repaired, though that will probably cost more than the replacement driver if done professionally.

The problem with replacing drivers in a ported system is that it is very difficult to find a driver with specifications close to the original. It's much less of a problem for closed box speaker systems where the match need not be very close at all. The driver JBird suggested was likely intended for a closed box system, and in a ported system it needs a much larger box.

[jbird604]

Yes, those drivers from Parts-Express do look nice, and I have to trust toodles on the calculations, so perhaps they are technically closer to the originals that the ones I suggested.

But I wonder if the response down below 100 Hz matters at all in this setup, as all the manual channels are all crossed over to the subs at some point. I'd guess that the FR1.7 only needs to work down to around 120 Hz or so.

At any rate, full honest disclosure here, as a lifelong experimenter and non-conformist, I've used a lot of different 8" drivers over the years to repair the FR1.7 cabinets. My favorite one in the past 10 years has been a driver that we got from MCM before they were swallowed up by Newark. (It seems that more and more of the best drivers MCM was offering are becoming NLA from Newark, as they aren't nearly as interested in the speaker driver market as MCM was.)

The driver I was using up until just now (when I discovered Newark has stopped having it) was an 8" accordion-surround paper cone speaker branded MCM Audio Select. It was a "pro audio" driver with a relatively stiff suspension, but also highly efficient, with a stated (but doubtful) one-watt sensitivity of 94 dB or so, as I recall. I'm sure that technically it was entirely wrong for the ported box of the FR1.7, but in practice it actually improved the sound of 1990's Rodgers organs, with a bit of extra punch in the region of about 150 Hz to 500 Hz, I'd guess. And I could guarantee the buyers that they would never again have foam issues!

Of course we always re-voiced a 90's Rodgers digital with the GC-8 machine or the GC-10 software after changing out drivers, so if there were any spectacular irregularities we'd have fixed that. But in most cases, I found it unnecessary to do any response smoothing, as the new drivers had a very nice full-bodied tone that the owners and players liked better than the original.

I find it puzzling actually that Rodgers used these expensive Peerless foam-surround woofers in the FR1.7, knowing that it be carrying very little signal in the low bass region. I think someone up there thought they needed to use relatively high-end drivers in these cabinets so they would seem to be as classy as the Allen HC series, even though they served an entirely different purpose in Rodgers organs, with their automatic subwoofer crossover systems.

[Historyguy101]

My calculations show that the replacement driver that JBird suggested will have an increased response in the bass range from 60 Hz of about 3.5 dB returning to normal response at around 200 Hz--that's not a huge hump, but it will be there. It also means response below 60 Hz will taper off faster than the original driver. Essentially it is giving up the bottom half octave response of the speaker system.

Is that critical? That depends upon what voices and pitches are routed through the speakers. The driver is low enough in cost that you could buy one and try it out before you decided to do all of the speakers that way.

This driver is closer in specifications to the original, and performs better in that size cabinet, and is about $25: https://www.parts-express.com/dayton...oofer--295-310

To get the exact same performance as the original driver, it would be best to have your drivers repaired, though that will probably cost more than the replacement driver if done professionally.

The problem with replacing drivers in a ported system is that it is very difficult to find a driver with specifications close to the original. It's much less of a problem for closed box speaker systems where the match need not be very close at all. The driver JBird suggested was likely intended for a closed box system, and in a ported system it needs a much larger box.

Hi Toodles-- Thanks for your response. Are you in agreement with jbird604 that we should just replace the drivers as opposed to repairing the surround round around the woofers? If so, what about this driver? https://www.parts-express.com/peerle...ofer--264-1098
Seems like that this driver may be the closet to the original Peerless driver. Thoughts?

[toodles]

Repair by replacing the surrounds on the woofers is a good option, but it will probably cost as much or more than just replacing the woofer. One repair facility charges $35 to repair a speaker of this size, plus shipping costs. So the decision on which to do depends upon how much you are willing to spend.

The Dayton driver I suggested does have a rubber surround, so it is immune to the foam rot that your original speakers suffered, so I would probably go with that driver instead of repairing the old ones. There is nothing wrong with just replacing the driver if you can get performance close to the original.

As to the original choice of Peerless drivers for this system Rodgers probably got these at a very reasonable price because they were buying in volume.

[toodles]

That Peerless driver should be fine--but I don't know that you'd really be gaining any performance over the Dayton driver I suggested for more than twice the price.