You’re welcome and I look forward to your build.
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+1 All this talk about vintage Radio Shack drivers has gotten me digging through my back issues of Speaker Builder Magazine and also digging through the on-line vintage Radio Shack catalogs.
Here is what I found regarding the 4" RS woofers:
40-1022A: Sold by RS from 1984 to 1992 with mfg t/s specs of Fs 55Hz, Qts 0.35, VAS 0.23 cu.ft., SPL 84dB 1W/1M. These had smooth paper cones and rubber surrounds.
40-1022B: Sold by RS from 1992 to 1998 with mfg t/s specs of Fs 85Hz, Qts 0.47, VAS 0.23 cu.ft., SPL 84dB 1W/1M. These had “ribbed” paper cones and rubber surrounds. Magnet and basket look the same as the 40-1022A’s.
40-1030: Sold by RS from 2000 to ??? with mfg t/s specs of Fs 85Hz, Qts 0.62, VAS 0.10 cu.ft., SPL 87dB 1W/1M. These had smooth polyproplyene cones and rubber surrounds. Magnet and basket look the same as the 40-1022A’s.
I used the 40-1030 and liked them a lot.
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The manufacturing location change on the 1030 mid-run is interesting, everything appears physically identical except the cone color. Wonder if it is more of a place of assembly change with parts they already had on hand. Funny that they changed it, the lighter cone looks pretty nice.
Back in high school wood shop class, I built a 2 way tower with the 8” poly woofers and the soft dome tweeter they had back in the 80s. It was a sealed design with a Fb of 51 hz. I was proud of those speakers!
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Here are a few photos showing the cone color and ribbing differences:
Pic 1: My 1989 Symmetrical Isobarik build, which I brought to InDIYana in 2016. These use a set of eight vintage 40-1022A woofers in an MTM isobarik configuration. This is the smooth paper cone version:
Pic 2: Here are my two electronic workbench speakers, which use one left over 40-1022A driver from my original 1989 Symmetrical Isobarik build (right channel) and one 40-1022B “ribbed” paper cone driver I picked up a few years later (left channel).
Pic 3/4: Here are the two pair of 40-1030 drivers that I’m currently boxing up for shipment. The cones are all made of textured type polyproplene, but they look somewhat different. I did t/s measurements on all of them and discovered that the pair with the darker shaded cones have a slightly lower Fs measurement. I’ll include complete t/s parameter printouts in the box.
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They all look nice. They are stout little drivers!
It’s kind of like the 1014a vs 1036 woofers; nearly identical but just a touch different specs, mostly with those is the sensitivity difference of at least a db. If crossed low one may never know the difference, or in such a low power application a 20w 1 ohm resistor would solve it. I’m super happy to have a matching pair now though, it would bother me to no end knowing they were different drivers.. 
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Got an awesome package from Bill S, thanks Bill! Bill also took the time to break them in, and do dats measurements with the drivers both warm and cool. Very nice to have, interesting to see the difference coil temp makes on them.
As Bill mentioned, he set me up with two different variations of the same part number. Interesting to see the differences, both physically and spec-wise, despite being the same number. The blacker cone is made in Japan, and the grayer cone is made in Malaysia. The motor and frame look identical.
I will be starting a build thread and dive into the details there.
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