AR 3 1/2" multi purpose driver

[dynaco_dan]

Hi there

A few photos of the versatile 3 1/2" driver AR bought from Carbonneau and modified at their plant.

I have seen and will post, when I can find them, photos of the driver, early on without the fiberglass under the screen.

I do not know what purpose the added fiberglass served with this driver.

The driver was used in the early AR-1X, AR-2X, AR-2AX (mid) and AR-4 speaker systems.

Later on AR produced the 2 1/2" cone tweeter which replaced all but the AR-2AX mid drivers.

A recent idea came to me, what if AR had used this newer tweeter in the AR-2AX speaker system. MMMMM

Maybe some reader has experimented or heard of one with this idea. MMMMM

The one I took photos of has a fabricated wire resistor, likely of Nichrome Resista wire, a wire that has a

specified resistance measured per inch, foot, yard or meter.

They used this particular section to parallel the tweeters higher resistance.

I took several angle shots to show as much detail as I could.

I don't have a macro lens for my FZ-20 so I can't do much better, yet.

AR used a brass short ferrule in two places to hold the board off of the cabinet wall.

I suspect they were aware of the heat potential and wanted a chimney effect to keep the wire cool.

The black painted and routed board is the adapter plate used to replace the dual cone tweeters in the AR-2A speaker system.

It was available, as were other kits, as a DIY kit to AR customers for around $15.00 PP paid, I believe.

The board was sealed with putty and machine screws were tightened into T-nuts.

A very versatile driver with a long history.

[Steve F]

The driver was used in the early AR-1X, AR-2X, AR-2AX (mid) and AR-4 speaker systems.

Later on AR produced the 2 1/2" cone tweeter which replaced all but the AR-2AX mid drivers.

A recent idea came to me, what if AR had used this newer tweeter in the AR-2AX speaker system. MMMMM

Hi Vern,

I asked Roy Allison back in 1972 why the 2 1/2" driver was not used as the midrange driver in the 'new' 2ax, since the 2 1/2" unit had replaced the 3 1/2" in the 2x and 4. He never gave me a direct answer. When I pointed out that the new 2x and the 4x crossed over at 1200 vs. 2000 for their predecessors and that using the 2 1/2" driver would have likely allowed AR to drop the w-mid x-o to 1200 instead of the 1400 it was for the 3 1/2" unit, he said the difference "wasn't significant." I would have thought that simply standardizing on parts would have been reason enough, but I guess not.

I have also written here in years past that I think AR may have wanted to retain at least something in common between the old and new 2ax from a marketing standpoint, so they could justifiably retain the same model number, which had acquired substantial marketplace equity by then (1964-1970). That would have been tougher to do if all three drivers had changed. Of course, I may be over-thinking this by a huge degree, as most uber-hobbyists tend to do.

BTW, I don't recall the 1x ever using the 3 1/2" driver. I thought the 2 1/2" was the service replacement for the 8" Altec in AR-1s once the Altecs were no longer available. I wonder how many brand-new 1x's were manufactured? Couldn't have been too many, although that model is actually listed in the late-60's AR full-line brochure (with a 2 1/2" tweeter), so they must've made a few.

Steve F.

[dynaco_dan]

Hi Vern,

I asked Roy Allison back in 1972 why the 2 1/2" driver was not used as the midrange driver in the 'new' 2ax, since the 2 1/2" unit had replaced the 3 1/2" in the 2x and 4. He never gave me a direct answer. When I pointed out that the new 2x and the 4x crossed over at 1200 vs. 2000 for their predecessors and that using the 2 1/2" driver would have likely allowed AR to drop the w-mid x-o to 1200 instead of the 1400 it was for the 3 1/2" unit, he said the difference "wasn't significant." I would have thought that simply standardizing on parts would have been reason enough, but I guess not.

I have also written here in years past that I think AR may have wanted to retain at least something in common between the old and new 2ax from a marketing standpoint, so they could justifiably retain the same model number, which had acquired substantial marketplace equity by then (1964-1970). That would have been tougher to do if all three drivers had changed. Of course, I may be over-thinking this by a huge degree, as most uber-hobbyists tend to do.

BTW, I don't recall the 1x ever using the 3 1/2" driver. I thought the 2 1/2" was the service replacement for the 8" Altec in AR-1s once the Altecs were no longer available. I wonder how many brand-new 1x's were manufactured? Couldn't have been too many, although that model is actually listed in the late-60's AR full-line brochure (with a 2 1/2" tweeter), so they must've made a few.

Steve F.

Hi Steve

My guess about the earliest AR-1X using the 3 1/2" driver, Steve.

BTW, I don't recall the 1x ever using the 3 1/2" driver. I thought the 2 1/2" was the service replacement for the 8" Altec in AR-1s once the Altecs were no longer available. I wonder how many brand-new 1x's were manufactured? Couldn't have been too many, although that model is actually listed in the late-60's AR full-line brochure (with a 2 1/2" tweeter), so they must've made a few.

You may be well on right, Steve, when I dig into some more AR literature I still have in boxes, I will return with the update.

I don't have a picture or spec sheet in-hand with the facts, yet.

It was used to replace the 8" Altec tweeter and it was renamed AR-1X, according to my AR warantee notes.

This was a message from AR when the Altec driver was no longer available.

Why it stands out is because my note has Altec spelled as Altex, as was heard over the phone.

When I had my first AR-4X's I was dreaming of adding a single AR-1X as a center/bass fill, never happened.

I'm sure I was heading for a divorce and backed off.

This would have been around 1967 - 68 and I believe at that time the AR-1X had a 2 1/2" tweeter, the same as my AR-4X.

I may have a catalog with the AR-1X photo still un-scanned.

I believe the AR-4 transitioned to the AR-4X between 1964 and 1966.

The AR-4 was written up in the Consumer Reports, I had on-hand, as well as the AR-3 speaker, which the crooked salesman turned both into junky sounding.

As a low paid apprentice I certainly learned the hard way not to believe sales people paid on commission.