Rebirth of AR92

[Giorgio AR]

A friend of mine has two AR92 pairs, who have been in the cellar for about 5 years.
A couple has non-original woofers, the second pair, the protagonist here, has woofers with crumbled foam and a dent on a midrange dome.
We started with external cleaning, the cabinets then received a light coat of linseed oil.
The 200033 original woofers with a round magnet (detected resistance of 3.5 and 3.6 ohms) were disassembled and taken to my house for refoaming, at the time I put in their place a pair of my 200040 woofers with square magnet, visible in the last photo (resistance detected of 6.4 and 6.4 ohms, aesthetically they are the most similar to the original, foam glued under the cone).
I fixed the dent of the midrange, no changes were made to the crossover.
Connected to a Technics SU-V7 amplifier they have shown a splendid sound, no imbalance between low frequency and the rest of the range: mid switches. and tw. on the back set to -6db both.
A wonderful pair of AR92s.

 

Back of 200033 original woofers

 

Repaired dent of the midrange

 

Front of 200033 original woofers

 

The speakers just arrived from the cellar

 

Speakers with woofers replaced

 

Details of the dented midrange

 

Replaced 200040 woofers

[ra.ra]

Hi Giorgio, perhaps this thread might turn into a good discussion about AR's various 10-inch woofers. Also, I just want to point out two small typos - - your photo captions should note 200033 woofer (and not 200030). One other observation - - it is interesting to see AR-92's with real wood veneer cabinets - - I believe that in the U.S. these were only available in faux wood vinyl.

Am happy to hear that your woofer substitution has yielded satisfactory results, but after looking at the original uses of these woofers, this experiment surprised me a bit - - at first I would not have anticipated such pleasant results. Quite possible that I've omitted something here, but I think the 200033 woofer was used only in the AR-92 (4-ohm three-way speaker, x-o freq. 700Hz). Similarly, the 200040 woofer was initially intended for the AR-14 (8-ohm two-way speaker, x-o freq. 1300Hz) and soon thereafter was used in another two way model, the AR-38s (8-ohm, 2000Hz). During those late 70's / early 80's years, the 10-inch 040 woofer also found its way into two subsequent three-way models: the AR-48s (6-ohm, 400Hz) and the AR-48b (6-ohm, 400Hz), so I guess it should not be surprising that the 040 driver can work well in a variety of configurations. Additionally, it is most likely easier to obtain than the original 033 woofer from the AR-92.  

And although I am not skilled enough to decipher all the technical specs shown here, these two woofers (033 and 040) do have rather different performance parameters according to specs found on AR drawings (see attached) .

 

[Giorgio AR]

Thanks for the note, I got the n° of the AR92 woofer wrong, the correct number is rightly 200033, I corrected my post !!
Yes these AR92 are veneered in wood, as well as the other couple of my friend (already taken from the cellar a speaker of the second pair, now stacked under the working AR92)
Regarding the 200040 woofer, as you wrote, it is also AR48s, different from the ones I inserted in the AR92 with the color of the paper cone: light gray in AR48s, dark gray in AR92, I am attaching photos with my AR48s couple to illustrate the cone (date 82/37), photo of both after refoam and photo of the back with type label and date.