Infinity RS3A Project

Seppo said:

I popped the woofers in my RS-IIIa's and RS-IIs out just the other day to check the wiring, and see if I could swap the woofers on the fly (nope, soldering needed on the RS-II side). I also took a few photos, thinking that someone might find them useful at some point...and here we are...

Top woofer:

Bottom woofer:

And both in the same picture:

In short, you have to have the dual woofers in series, and in-phase (same polarity). If you put the woofers in opposite phase (opposite polarity strictly speaking), you will get very limited bass. Trust me, been there, done that



And, while we are at it, just for the sake of comparison, here's one of the woofers in RS-II:

As far as I can tell, the woofers are identical, but the wiring is much much heavier gauge in RS-IIs.

Click to expand...

Ha! Who would have thought red stripe on terminal does not indicate red wire. I switched it and did a L/R comparison and that was definitely the problem. Still sounds super tight but thanks so much for the confirmation!

Nice pics. Looks like someone may have rewired the rsII. Mine are the clips with thinner wire. Did you notice each woofer is in its own incloser on the rsII. Pretty cool...
Jim

slimpikkins said:

Nice pics. Looks like someone may have rewired the rsII. Mine are the clips with thinner wire. Did you notice each woofer is in its own incloser on the rsII. Pretty cool...
Jim

Click to expand...

Interesting to hear. I got the RS-IIs from the original owner, and he had them refoamed "recently" "by a professional" (somewhere in Greater Toronto Area). So they must have upgraded the wiring at that point, and soldered the connectors. All good.

Unfortunately the re-foaming was not done well, and there is gaps between the new foam and the cone. Basically who ever did this, had tried to glue the foam to the back of the cone, and had failed to do a 100% job. Per my experience it is better to glue the foams on the top of the cone. It is easier to apply pressure that way and make sure there is no gaps.

Anyways, that's why I was hoping to simply throw in the RS-IIIa woofers to my RS-IIs. 'foghead' did a great job re-foaming the woofers in his RS-IIIa's a few years back.

PS: And yes, two separate boxes for the woofers is really cool. Infinity advertises it as Watkins, but using two woofers instead of two voice coils in one. And I can very clearly notice how the bottom one is cutting off at much lower frequency than the top one.

I am a physicist by training, and part of the pleasure for me in this hobby is reading about and seeing and hearing all the physics in action...and there is a lot of it with vintage Infinity...

Here is the refinished speaker. I used some foam from a craft store and attached with some adhesive. It looks, and sounds, perfect as far as I can tell. I bought two larger sheets instead of the split initial design and if I ever feel inspired I will swap out the foam, but the speakers cleaned up really nicely and I cannot wait to get a listening session in. They are very clean sounding, and the phase linear is very clean, so even initially I am hearing things I never heard before!

Glad it was a cheap and easy fix.
That's the best kind.

I see in the pic that the rsII refoam was not done correctly. Infinity had the surrounds glued to the top of the cones. I doubt it makes a difference but...Maybe you could just reglue the one area that came off. Nice looking setup.
Jim

getting the original adhesive off of the face of these poly cones to a level where it would be visually presentable would be pretty remarkable. If it looks good and sounds good I would just do an updated glue job with a slow setting glue like tacky glue in as minimal a layer as possible to allow for sealing and adhesion and call it a day. I think scraping the material off of the underside of that would risk VC damage while deforming the cone while stabilizing it during the foam stripping process, but that is just me.

looking good...

When replacing foam surrounds, I have ALWAYS found/made something the same diameter as the ring's sealing area, and used this item w/ a small amount of weight to hold the glueing areas tight. I know the setup time for my glue, and I will check the position of the rings/alignment of everything, before they become "not movable".
FYI: All replacements I have done, (30 + pairs) have all stated glue the rings on the FRONT of the cones.

my two cents Stu

I just bought a pair of Infinity RSiiia! While doing a search on Craigslist, I found a pair located in Tucson, which is a two hour drive. I bought them in as-is condition and the gentleman said, "these are as-is because they've been sitting in the garage quite awhile. The old gentleman is a musician and married Arnie Nudell's sister. While loading them up, I quickly took the grills off to check the drivers. They were all there. Brought them home, hooked them up to a Technics su-v650 integrated amp running a rotel cd player. All drivers are in excellent condition!!!! The speakers are now being tore apart to clean the Arizona dust off of everything! So a new restoration project(along with my rs6 which I have a new woofer coming for that one). It's good to see such a loyal following for these speakers. I plan on comparing them to my Carver ALS Plats that I have in the living room.

michael1968 said:

I just bought a pair of Infinity RSiiia! While doing a search on Craigslist, I found a pair located in Tucson, which is a two hour drive. I bought them in as-is condition and the gentleman said, "these are as-is because they've been sitting in the garage quite awhile. The old gentleman is a musician and married Arnie Nudell's sister. While loading them up, I quickly took the grills off to check the drivers. They were all there. Brought them home, hooked them up to a Technics su-v650 integrated amp running a rotel cd player. All drivers are in excellent condition!!!! The speakers are now being tore apart to clean the Arizona dust off of everything! So a new restoration project(along with my rs6 which I have a new woofer coming for that one). It's good to see such a loyal following for these speakers. I plan on comparing them to my Carver ALS Plats that I have in the living room.

Click to expand...

Congrats!

RS-IIIa/b's are excellent all around speakers, and those EMITs are just sweet. These speakers are also a relatively easy load, so there should not be any issues finding proper amplification. My Onkyo A-9070, pushing clean 140 wpc at 4 Ohm, just made those babies sing w/o sweat.

thanks Seppo. I plan on using one of my modified BGW 750C amps with these speakers. I am using a Carver C1 preamp. Already got all drivers out, both crossovers out. Ordering parts right now. The surrounds looked to be in good condition, but when I touched them, my fingers went straight through!! So new surrounds are ordered. QUESTION: Which crossover design would one use for the RSiiia? Mine are the original and follow the schematic correctly. But I noticed that there are other schematics/design are using. Which one would be best suited?

My BGW 750C is pushing 265 watts per channel at 8 ohms. I have two of them for running the Carver ALS Plats in bridged mode. The Carvers aren't up due to a planar tweeter needing repairs. So no big deal to pull the BGW over to the Infinity speakers.

Seppo said:

I popped the woofers in my RS-IIIa's and RS-IIs out just the other day to check the wiring, and see if I could swap the woofers on the fly (nope, soldering needed on the RS-II side). I also took a few photos, thinking that someone might find them useful at some point...and here we are...

Top woofer:

Bottom woofer:

And both in the same picture:

In short, you have to have the dual woofers in series, and in-phase (same polarity). If you put the woofers in opposite phase (opposite polarity strictly speaking), you will get very limited bass. Trust me, been there, done that



And, while we are at it, just for the sake of comparison, here's one of the woofers in RS-II:

As far as I can tell, the woofers are identical, but the wiring is much much heavier gauge in RS-IIs.

Click to expand...

Could you do a diagram for the wiring because not having a go that's something I follow.

DEANO222 said:

Could you do a diagram for the wiring because not having a go that's something I follow.

Click to expand...

Please see here:
http://audiokarma.org/forums/index....iia-b-in-or-out-of-phase.590019/#post-7768342