Replacement woofers for vintage Infinity tower

[TLS Guy]

Thanks for the correction, right you are about the total impedance. I was thinking the series circuit followed the inverse square law for some reason...those classes were a few years ago
I checked into the schematic for the speaker and the also the owners manual. The manual states that the amplifier driving the woofers will "see" a 4 ohm load. The wiring diagram does show the woofers to be in a series circuit. So I guess each driver must be two ohms. Not impossible I guess but kind of an anomaly in my experience.
Yeah, yeah I hear ya about the Crown and am well aware of their issue. It's not possible for an output transistor to fail intermittently is it? I've checked for DC offset at the speaker terminals on the Crown and everything seems fine. None-the-less that amp will be finding a new home. I still think the Infinity bass EQ box is suspicious because both amps popped into protection mode when it was in the circuit. I've got it on the bench now to check for anything obvious.

This is why I'm worried you are wasting time and money, if the impedance of those speakers when hooked up is half the original then the crossover point will be doubled, if the impedance is doubled then the crossover point will be halved, for the woofers, but the other crossovers will not change, so you will have areal mess on your hands.

 

[TLS Guy]

You can search the part number on GGEC's site. Other than that you're best bet is searching JBL ES100. I searched for quite awhile before I found anything and what little I did find wasn't especially helpful.

As far as the polypropylene, I figure Infinity had access to paper cones and they would have kept production costs down. The engineering team at infinity chose the poly for a reason.

This video explains some of the reasoning behind Infinity's decision.

Start at approx 9:50

In my opinion, the weight/rigidity ratio tends to a theoretical advantage. Allowing fast transients while maintaining sufficient rigidity to keep the woofer more nearly a perfect piston.

That is a load of nonsense. All cone materials have advantages and disadvantages, all different. Doped paper cones can be very long lasting. There are good a bad drivers, with paper, plastic, Kevlar, graphite carbon fiber metal, and probably some I did not mention.

 

[lovinthehd]

I see a GGEC site, and this decoding for their part numbers https://www.ggec.com/transducers.html

 

[Nathan Rieben]

I see a GGEC site, and this decoding for their part numbers https://www.ggec.com/transducers.html

That's the same decode sheet I was looking at. I'm thinking TLS guy is probably correct when he says the recommendation's not a perfect replacement. In any case the new drivers are already on the way so what's to lose? If they're not acoustically pleasing I'll hunt around for originals. If they work though it will be great to have a modern source for Infinity RS stuff. Either way it can't hurt to try. I'll post my impressions once I get them up and running.

 

[lovinthehd]

Good luck. I just didn't see anything specific about those drivers or their applicability to your situation (but didn't dig into it otoh, just not that interesting to me). TLS has pretty admirable speaker construction chops, way above my pay grade, but do have some experience with box size/style and driver t/s parameters go, too and just not seeing any specifics about why they're a match. Just curious what specifics the "help" from the Samsung/Harman team were particularly....

 

[Nathan Rieben]

I opened the low frequency contour box last night but didn't see anything abnormal so I put that back together. Could still be something wrong there I guess but nothing obvious burnt or lose. No bulged capacitors etc.
I also started looking at my woofer cross-over tonight. Unfortunately, the cross-over unit seem to be more or less integral to the cabinet. I don't feel like separating glued seams so I guess I have to test components and re-solder while sticking my head through the speaker cut-outs. Thankfully there's two...one for my head and one for my hands I'm no electrical whiz kid so thankfully the bass circuitry is simple. I get a little swimmy headed just looking at the mid/tweeter network.