Infinity RS3A Project

foghead

Active Member
Here's the pair I recently acquired off Craigslist in as-is condition. As anyone can see, they need a pair of woofers and a refoam of the other 2. Also, the foam around the tweeter and midrange is pretty well toasted. The wood is in almost perfect shape though... was really dry but is relatively chip free. All in all, I feel they were worth the $125 they set me back. Around the Niagara Falls, NY area, you don't see higher end gear like this too often.

Now... the search for woofers and foam starts!!

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Nice deal, woofers are abuntant for those at the moment. You will love those once you get them together.
Good luck and post pics and opinion when your done.
Jim
 
When you pull the woofers post the model #. I have an extra pair that are grey like that I'll sell you cheap if they're a match. They will also need new foam though.
 
When you pull the woofers post the model #. I have an extra pair that are grey like that I'll sell you cheap if they're a match. They will also need new foam though.

They are part number 902-4983/64139... although another individual said they could be part #902-2279. I think either would be fine as they're going to be used as a matched L/R pair. These are 10" even across the foam trim ring and roughly 4ohm.

Can it be??? :banana: I may have these up and running sooner than I thought!! I need to stop by Hobby Lobby to see if they have any crafters' foam that I could use for the tweeter/mid surround.
 
Woofers found from an outside source... Now - which will arrive in the mail first - the woofers or the box with all the refoam rings/adhesives? Stay tuned!!! (A few other sets of surrounds were also included... a stack of speakers here that have to be worked over, lol!)

For replacement foam around the tweeter and mid, a fellow AK-er turned me onto this stuff:

http://www.thefoamfactory.com/opencellfoam/filter.html :banana:

1/4" thick 20 or 30 pores per inch. I'll likely go with the 30 as it'll probably be closer to the original in firmness...
 
Becuzz I'm bored...

An update to the project... cabinets now stripped of mid/tweeter surround foam. 2 woofers now have fresh surrounds... just waiting for the other 2 to arrive!

One bare cabinet:

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Some pretty sad looking foam before I peeled it off: :banana:

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2 new surrounds installed and ready to rock:

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Those have the infinite baffle design woofers, so the best would be the one used in it, and the RS5B, not RS5! Another choice, the RS2. I would look for these first. If you cannot find one, then look at what was used in the RSB, some are clear, some are gray.

The last one I would use is the 902-2279/ 902-2279A, which are the rarest and cost the most. they were the 'one size fits all', but were in the RS2A/b with more varied Q specs and had a longer voice coil, not bigger, longer. The RSB also has a little longer voice coil and clear and gray are the same, while all the others are very close, the RS 2, RS3A/B and RS5 are best and probably most available.
 
Foghead,

I had a project pair of RSIIIb awhile back. I replaced the cloth on the grill and never replaced the badges because I broke one of them. I might still have the other one around somewhere.

I just looked at your pic. The IIIb and IIIa badges look slightly different. I'll confirm when I get home
 
AWESOME and thanks to all for the info! The woofers that are coming are from an RS3B. Longer voice coils eh? What would be the suggestion for placement? Bottom spaces or top spaces or re-foam and wait until I find some 3A units? I'll do a pro job on them and they'll be worth cash when I'm done... :yes:

InfinityBob - is there a link that you can send regarding the 'infinite baffle design woofers'? Kinda curious as to how that's all supposed to work... is it part of the reason why the company was called 'infinity'?

t40kill - If you have an extra badge, I'd really appreciate it!!! :banana:

Kinda surprised that nobody commented on my sad looking face that I drew in the foam... :smoke:
 
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The last one I would use is the 902-2279/ 902-2279A, which are the rarest and cost the most. they were the 'one size fits all', but were in the RS2A/b with more varied Q specs and had a longer voice coil, not bigger, longer. The RSB also has a little longer voice coil and clear and gray are the same, while all the others are very close, the RS 2, RS3A/B and RS5 are best and probably most available.

Infinitybob, the 902-2279 and 902-2279a are not the same. I started a thread about this last year which did not get much action. Look at the picks in that thread the cones and magnets are different.
http://www.audiokarma.org/forums/showthread.php?t=403697
Infinity use the "a" as replacement only, not sure what the deal is. My RSII's also have the "a" woofers. Any light on this would be great.

By theway foghead I missed the face the first time, very sad indeed. Nice job on the woofers, mine always work fine but look like a 4th grader did them.
Jim
 
Infinitybob, the 902-2279 and 902-2279a are not the same. I started a thread about this last year which did not get much action. Look at the picks in that thread the cones and magnets are different.
http://www.audiokarma.org/forums/showthread.php?t=403697
Infinity use the "a" as replacement only, not sure what the deal is. My RSII's also have the "a" woofers. Any light on this would be great.

By theway foghead I missed the face the first time, very sad indeed. Nice job on the woofers, mine always work fine but look like a 4th grader did them.
Jim

Is there a difference between the 902-4983 woofers that I already have and the 902-5079 units that I have on the way? I was kinda under the impression that the #'s after the dash were more of a lot # than an actual change. Am I wrong?? They appear to be identical...
 
Not certain of this but my understanding from long ago by heresay was Infinity used those numbers to distinguish the speakers design parameters as much as anything. There may be several woofer numbers that work for a specific model but that number, 902-4983 designates one model that worked for a certain speakers design characteristics while 902-5079 could be different in small but important ways. Unfortunately it was also used to signal when a different manufacturer filled the order from the one that built the original batch. In other words it's better to stick with what you know to be accurate or the sound "could" be different. The crossovers may not work the same, etc. When I first got my RS3b's I talked with several owners on line at the time and they all stated either refoam the ones you have if it comes to that or find exact matching ones. The ones Infinity said would work weren't clear as the original poly's and sounded much different to the point they yanked them and last I heard were waiting on originals. That was 9 years ago.

I do know while looking for a pair of woofers for my little Qe's, I have been able to verify at least 5 different companies made speakers to fill the sales volume and minor changes to design. Original part numbers as listed in the tech sheet don't even match the first ones to come off the assembly line as the original ad shows them with 8 holes and the Qe tech sheet shows 4. And not all of them had Infinity numbers on them.

I would suggest doing a lot of research behind those replacements...
 
Not certain of this but my understanding from long ago by heresay was Infinity used those numbers to distinguish the speakers design parameters as much as anything. There may be several woofer numbers that work for a specific model but that number, 902-4983 designates one model that worked for a certain speakers design characteristics while 902-5079 could be different in small but important ways. Unfortunately it was also used to signal when a different manufacturer filled the order from the one that built the original batch.

As it stands, they're the best that I could find for the moment... I'll measure as much as I can before running them. If I had all 4 original drivers, this would be a moot point but seeing as how 2 were missing, this will be my starting point.

Looks as though the crossovers are the same spec-wise according to here: http://www.infinity-classics.de/technik/manuals/RS_IIIA_technical_sheet.pdf

Thanks for the info!
 
Really? I have yet to find an infinity crossover that matched the spec sheet. Congrats?

My foam looked about like that on the top, and my woofers do look like a 4th grader did them - but they sound great.

Be aware that as frequency drops below about 40hz, impedance drops fast.
 
Really? I have yet to find an infinity crossover that matched the spec sheet. Congrats?

My foam looked about like that on the top, and my woofers do look like a 4th grader did them - but they sound great.

Be aware that as frequency drops below about 40hz, impedance drops fast.

I didn't go through the crossovers in my speakers, so my guess is only that it may match the diagrams. I'll look later...

I'll keep an eye on stuff, but who knows. Impedance isn't a problem for my equipment... I'll just check some numbers when the woofers are done.
 
You might find this little back and forth interesting http://archive.audioreview.com/13/0EE90FAD.php as it explains a few things about the RSIIIb's specifically and their nature. In other reviews I've read about before they have been measured to go down as low as 1 ohm at high volumes on music that goes down low. I have to watch it if I use the Kenwood M2 (220w and will blow a fuse in the 2-3 ohm range) to drive them while the Hafler DH500 (255w but will handle almost anything down to 1) just flows along quite merrily. I'd certainly be cautious of your amp choices especially if you intend to play them loud.

This isn't the first time I've heard they need extra bracing, new caps and better internal wiring but as mine have been working just fine for the 10 years I've had them I don't want to play with them just yet. I've much to learn about this hobby and will be experimenting with other speakers to get more familiar before working on these. I have had to DeOxit the pots once in that time but that's all.
 
Foghead, I looked around, but I can't find the badges. Maybe I threw them away. If they come up, I'll let you know.
 
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