Infinity 10-inch poly woofer compatibility

[geoff727]

Concerning the 10" polypropelene woofers (RS-IIIa/b's, RS-II's, RS-IIa/b's, etc.), I've seen a lot of these woofers with different part numbers. The 902-xxxx number. And there seem to be multitudes of the second number that appears on Infinity drivers (that ends in 3 capital letters). Externally they appear identical. Are all these woofers compatible (magnets, voice coils, impedance, freq. response, etc.)? Does anyone have a comprehensive explanation of what this numbering system signified?
Thanks all.

 

[Nakdoc]

The second number is a production code or something. There should be no difference in drivers witht he same 902-xxx number. Infinity has been making some goofy substitutions lately.

 

[geoff727]

So, for example, there's a pair of 902-5079's ebay right now, which should be straight across compatible with 902-2279's, which should be straight across compatible with the ones in my RS-II's (which are another number). Is that correct? Again, visually, they all seem identical.

 

[Tedrick]

This might be a question for Infinity. I've passed on those 902-5079 woofers a couple of times because I don't know if they are equivalent to the 902-2279A that's in the RS-II/a/b or RS-IIIa/b. If they are not direct replacements, there are probably differences in the voice coil or magnet structure that would give them different output characteristics than the stock woofer, and thus a potential matching issue.

 

[Arkay]

Don't mean to hijack the thread, but this seems to fit right in with the topic of the OP:

I haven't compared serial numbers, but I have two styles of infinity 10" poly woofers. There are the ones like you are referring to, with "bullet-nosed" poly dust covers, and then what I presume are somewhat later ones that appear to have similar cones, spiders and baskets, but which have more ordinary, flattened dome dust covers. I was told these came out of a slightly later RS series from Infinity but I don't have exact information.

I'd be curious to know if these are at all compatible with the earlier (and I have always presumed superior) bullet-nose-dust-cover woofers. I've always assumed they wouldn't be as good, but have hung on to them as potential spares, just in case they were actually equivalent.

Here is what is on the back of one of the "domed" (not "bullet") ones:

902-2864
67428
472TNB

It's possible the different dust covers are from someone's re-foaming job, but I think they are original, and thus mark these as different speakers. Maybe this is somehow reflected in the numbering? I never recorded the serial numbers on the ones actually IN my speakers, and I'm not about to remove them right now just to get the numbers, so I can't give any numerical comparisons there.

Can anyone say anything definitive about these? Worth hanging on to? Comparable (or not) to the bullet-nose ones? Anyway, I'm glad this question was raised because I've been wondering about these for a long time. I hope someone really KNOWS for sure the answer(s) to this stuff.

If, as Nakdoc says, all the 902-XXXX speakers are identical, then there are some MUCH CHEAPER sources out there for replacement drivers, taking them from later (less pricey) models and sticking them in the earlier speakers... IF you can live with different dust covers. I always assumed that the bullet-nose shape of the dust covers made at least some small difference in the sound output, though. {Then again, if it does, you could always vacu-form replacement dust covers using old poly milk bottle material over a mold made from a "real" one... ).

 

[ugornot]

The speakers are not all the same. The 6000 series 10" woofer is slightly smaller than the rs series. I also believe they were 4 ohm also. These are the 902-2864 I just sent to Tinkerbelle. I had to make new holes to go in a RS5b. They also left a small gap around them. All I can really say id the poly woofers from the 5B and IIIb are not the same size as the later 5000, 6000 series.

 

[Tinkerbelle]

I would suspect that the different part numbers may have slightly different performance (Thiele/Small) parameters, with different low frequency performance. Cabinet volumes are matched to these parameters for optimum response (or drivers designed to meet loudspeaker performance needs). So, while it may well be possible to physically interchange some of these and their impedances may be the same, the speaker response could be different when placed in a different size (volume) cabinet.