AR-2x replacement tweeters

[dls123]

Hi

I rescued a nice pair of AR-2X speakers from the thrift store for $5. Surrounds are in good shape, cabinets and grills are pretty good too. I will pull a woofer and get the cap values and replace them, but the tweeter on one is not working. The other tweeter is, but speakers are pretty rolled off. Possibly the crossover is damaged on the one, possibly the tweeter. Jumper wire on the terminals is connected. I know this is not one of the best models, but I am willing to throw a few dollars at them to have a nice pair of bench or office speakers. I am quite familiar with the 3a having restored a pair (wonderful). Does anyone know of a good replacement tweeter that will fit the opening and mate well with the crossover? Not looking for a $100 pair of tweeters, just something inexpensive that is a better tweeter than the original cone ones. Also, when I push on the woofer gently it springs back very quickly compared to the 3a woofers. I assume this indicates a poor cabinet seal? Again, the surrounds look very good, possibly have been redone by someone. Any tweeter advice appreciated if anyone has played with a pair of these!

cheers,

Don

[JKent]

Hi Don

Sounds like a nice find.

We're not all familiar with the 2x. Unfortunately there was a confusing number of 2 series ARs: 2, 2a, 2ax and 2x. I've had the 2 (in truth, just the cabinets), 2a and 2ax but have not seen the 2x. Maybe a photo would help, and let us know the diameter of the tweeter. I wonder if the relatively inexpensive Hi-Vi that Roy has used successfully with the 3a would work. Is it a 3-way speaker like the 2a and 2ax, or a 2-way like the 2? I'm assuming you checked the tweets independent of the xover, because the pots could be corroded or you could have a bad cap. But I assume you know that, since you have restored a 3a.

It's my understanding that the caps in the 2x may be paper-in-oil, in which case you may want to keep them.

Kent

[genek]

We're not all familiar with the 2x. Unfortunately there was a confusing number of 2 series ARs: 2, 2a, 2ax and 2x. I've had the 2 (in truth, just the cabinets), 2a and 2ax but have not seen the 2x.

The 2x is basically a 2-way version of the 2ax without the dome tweeter. It was not a predecessor to the 2ax, but was sold from 1970-1971. I think it was meant to be a "budget" 10" woofer model, which would probably make it a predecessor of the AR-8. It probably has either a wax block cap or a cylindrical cap like the late-classic models.

[Steve F]

Hi Don

Sounds like a nice find.

We're not all familiar with the 2x. Unfortunately there was a confusing number of 2 series ARs: 2, 2a, 2ax and 2x.

Kent

Sorry to bore long-time readers with this yet again, but here is the history of the AR-2 series:

The original AR-2 was a 2-way that came out around 1957 a 10” cloth-surround woofer with two angled 5” mid-tweeters.

The 2a followed and added the 1 3/8” ‘fried egg’ dome tweeter, making it a 3-way speaker.

Then AR replaced the dual 5” cones with a single 3 ½” cone, creating the 2x (2-way) from the 2 and 2ax (3-way) from the 2a. This was around 1964-65.

In 1970, AR re-did the 2x and 2ax, with very extensive modifications (although no model number change). You’ll have to examine your speakers closely to determine their vintage.

The ‘new’ 2x replaced the 3 ½” cone tweeter with a 2 ½” unit. The crossover went from 2000Hz to 1200Hz. The logo went from the square “AR” to a rectangular brass logo with de-bossed red ‘2x’ lettering.

The woofer went from a cloth surround to a foam surround. It would be highly unusual, to say the least, for a foam surround from 1970 to still be intact. A cloth surround from 1965 may not have crumbled into non-existence, but it is quite possible that it has dried out and become porous, requiring re-application of a suitable surround sealing treatment.

Check your speakers to see what age and variant they are. The 2x has never had a ‘bright’ character and it is not unusual for people to feel that it is somewhat reticent or “rolled off,” as you say. But “rolled off” shouldn’t mean “deficient.” The 2x (and its 8” cousin, the 4x) have a very pleasing, neutral tonal character that is quite satisfying on a day-in, day-out long-term basis.

Steve F.

[genek]

Then AR replaced the dual 5” cones with a single 3 ½” cone, creating the 2x (2-way) from the 2 and 2ax (3-way) from the 2a. This was around 1964-65.

In 1970, AR re-did the 2x and 2ax, with very extensive modifications (although no model number change). You’ll have to examine your speakers closely to determine their vintage.

We need to figure out a way to update the timeline in the library. It has the 2x starting production in 1970 and ending in 1971.

Would the 1964 version be old enough to have oil-filled caps? Do you know when AR stopped using those?

[dls123]

Sorry to bore long-time readers with this yet again, but here is the history of the AR-2 series:

The original AR-2 was a 2-way that came out around 1957 a 10” cloth-surround woofer with two angled 5” mid-tweeters.

The 2a followed and added the 1 3/8” ‘fried egg’ dome tweeter, making it a 3-way speaker.

Then AR replaced the dual 5” cones with a single 3 ½” cone, creating the 2x (2-way) from the 2 and 2ax (3-way) from the 2a. This was around 1964-65.

In 1970, AR re-did the 2x and 2ax, with very extensive modifications (although no model number change). You’ll have to examine your speakers closely to determine their vintage.

The ‘new’ 2x replaced the 3 ½” cone tweeter with a 2 ½” unit. The crossover went from 2000Hz to 1200Hz. The logo went from the square “AR” to a rectangular brass logo with de-bossed red ‘2x’ lettering.

The woofer went from a cloth surround to a foam surround. It would be highly unusual, to say the least, for a foam surround from 1970 to still be intact. A cloth surround from 1965 may not have crumbled into non-existence, but it is quite possible that it has dried out and become porous, requiring re-application of a suitable surround sealing treatment.

Check your speakers to see what age and variant they are. The 2x has never had a ‘bright’ character and it is not unusual for people to feel that it is somewhat reticent or “rolled off,” as you say. But “rolled off” shouldn’t mean “deficient.” The 2x (and its 8” cousin, the 4x) have a very pleasing, neutral tonal character that is quite satisfying on a day-in, day-out long-term basis.

Steve F.

Hi Steve,

Thanks for the info. They have the 2 1/2 in. tweeters and definitely a 10 in woofer with foam surround. It looks like someone did the surrounds already since they are in decent shape. So I guess I will pull a woofer and see what caps are in there. The pots are probably filthy so will spray them with contact cleaner. Still, the tweeter is nothing to write home about from what I can tell. I guess the best course of action is the replace the caps, clean the pots (or bypass them) and of course measure the resistance across the disconnected tweeter to make sure it is the same as the good one. Then, if I can get the other tweeter to work I can listen to what they can do. I suppose then that if I want to swap tweeters I need one that fits the opening, is the correct impedance and sensitivity, and can make it down to 1200 Hz, pretty low. Is there any documentation of the specs of the 2 1/2 tweeter?

I have a pair of KLH 17 that I rebuilt and they are pretty nice. Highs there are somewhat "rolled off", but mids to die for. These smaller AR speakers are what they are, not in the same league as their bigger brothers, but quite enjoyable. I have been listening to a pair of Klipsch Cornwalls lately that I turned into CornScalas. They are pretty amazing, but I always like playing with the AR speakers and always pick them up when they are a bargain. Then I find good homes for them with friends.

thanks,

Don

[Steve F]

Hi Steve,

Thanks for the info. They have the 2 1/2 in. tweeters and definitely a 10 in woofer with foam surround. It looks like someone did the surrounds already since they are in decent shape. So I guess I will pull a woofer and see what caps are in there. The pots are probably filthy so will spray them with contact cleaner. Still, the tweeter is nothing to write home about from what I can tell. I guess the best course of action is the replace the caps, clean the pots (or bypass them) and of course measure the resistance across the disconnected tweeter to make sure it is the same as the good one. Then, if I can get the other tweeter to work I can listen to what they can do. I suppose then that if I want to swap tweeters I need one that fits the opening, is the correct impedance and sensitivity, and can make it down to 1200 Hz, pretty low. Is there any documentation of the specs of the 2 1/2 tweeter?

I have a pair of KLH 17 that I rebuilt and they are pretty nice. Highs there are somewhat "rolled off", but mids to die for. These smaller AR speakers are what they are, not in the same league as their bigger brothers, but quite enjoyable. I have been listening to a pair of Klipsch Cornwalls lately that I turned into CornScalas. They are pretty amazing, but I always like playing with the AR speakers and always pick them up when they are a bargain. Then I find good homes for them with friends.

thanks,

Don

I'd also suggest following the "Crossover mods for the AR-4x" and "....4x II" in the 'Mods and tweaks' section. Speaker Dave (a very highly-regarded professional engineer with extensive speaker industry experience) and CSP member Zilch, a very talented and creative contributing member, have embarked on finding ways to improve the 4x's performance with some relatively minor crossover tweaking. The 2x is very similar to the 4x, and I'd guess that many of the comments and suggestions on the 4x would also apply to the 2x. The tweeters are identical.

Well worth the read.

Steve F.

[JKent]

A couple of thoughts:

Don't just spray the pots. Take them apart and clean the corrosion with a dremel tool wire wheel or with sandpaper. Then use your de-oxit and some dielectric grease.

I have some "NOS" AR tweets from a later model that were cheap from PE on close-out (see attached pic). Backs are marked AR-218V. Made in Taiwan. Let me measure them and if they seem suitable I'll sell 'em cheap These are the same ones Carl was selling here:

http://www.classicspeakerpages.net/IP.Boar...mp;hl=carlspeak

There is also mention of this tweeter here:

http://www.classicspeakerpages.net/IP.Boar...l=ar+3a+tweeter

OR: Speaking of Zilch, this could be the perfect pair of speakers for an E-Wave conversion. If the tweets are shot and were not impressive in the first place but the cabinets and woofers are good... could be a plan. You won't be desecrating a great pair of classic speakers--maybe really improving a so-so pair. I don't have the cost and parts breakdown, but you can follow the thread over at AK.

http://www.audiokarma.org/forums/showthrea...highlight=ewave

Zilch sells nice printed circuit boards for the xo for about 20 bux. Then you need some caps & resistors, 2 waveguide horns and 2 tweets from PE. This could be a great project!

Kent

[Zilch]

OR: Speaking of Zilch, this could be the perfect pair of speakers for an E-Wave conversion. If the tweets are shot and were not impressive in the first place but the cabinets and woofers are good... could be a plan.

AR2x has a significant advantage with respect to retrofit, as I recall -- in-line alignment of the woofer and tweeter, i.e., they are symmetrical.

Cone tweeters are generally able to play relatively low in frequency; few modern dome tweeters can get down into an equivalent range successfully, although domes' performance in this region may be enhanced with waveguides. The primary disadvantage of cone tweeters is that the dispersion narrows with increasing frequency -- they "beam." That's very much at odds with AR's fundamental system design objective of wide-dispersion constant directivity across the full bandwidth. They didn't call it that, but in retrospect, the intent is clear.

Vintage designers struggled with the dilemma: how can we make a tweeter that'll play low enough to mate with extended-bass acoustic suspension woofers and also maintain wide dispersion into the high frequencies for a successful 2-way system? AR never solved it in the vintage era and concentrated upon building 3-ways instead. By one view (mine), that's what the subsequent "fried-egg" tweeters by AR alums were about -- combining a ring-radiating midrange and a dome tweeter in a single device. That approach served Advent well, and Allison further refined this with his unique tweeter design focused upon delivering wide-dispersion high frequency response.

Dave and I have characterized the 2.5" AR cone tweeter as used in AR4x in the threads cited. You'll also find Ken's results from dissecting several of them linked there. Bottom line, from a contemporary perspective, they weren't "all that" to begin with, and many have deteriorated over time. Clues to AR's own view of them may be found in the 1970 Allison and Berkovitz paper available in the CSP library.

I consider AR2x an excellent candidate for upgrade/update, but have never had any to try various options. The results of eWaving Advents and AR4x have been stunning, but admission is $200 per pair. An inexpensive approach might be to install Advent tweeters and hope for an audible performance improvement....

[JKent]

I consider AR2x an excellent candidate for upgrade/update, but have never had any to try various options. The results of eWaving Advents and AR4x have been stunning, but admission is $200 per pair. An inexpensive approach might be to install Advent tweeters and hope for an audible performance improvement....

Well, since Don only spent $5 for the speakers and he said "I am willing to throw a few dollars at them to have a nice pair of bench or office speakers", what could be better than a pair of sonically "stunning" and visually pretty vintage AR speakers for just $205? An asset to any office, I'd say! And although I have not yet tried it myself, the E-Wave project looks like fun!

Kent

PS: What about this Zilch?

http://www.parts-express.com/pe/showdetl.c...tnumber=280-062

Super cheap, and one customer wrote "Very Good replacement for the AR2 tweeter paper cones. Clean and strong sound. One Piezo replaced two paper cone tweeters." Now I don't know the first thing about speaker design or crossover design, but if Don's looking for cheap maybe blow another 5 bucks for a pair of these and see what happens.

[Steve F]

Well, since Don only spent $5 for the speakers and he said "I am willing to throw a few dollars at them to have a nice pair of bench or office speakers", what could be better than a pair of sonically "stunning" and visually pretty vintage AR speakers for just $205? An asset to any office, I'd say! And although I have not yet tried it myself, the E-Wave project looks like fun!

Kent

Yes, that could work nicely.

The Advent tweeter is also an intriguing idea. Since the original Large Advent had roughly the same baffle size as the 2x and the two systems have very similar overall sensitivities, system impedance, etc, the Advent tweeter might work surprisingly well. (It crossed over at 1000 Hz.)

Plus, once Don cleans and restores the 2x's level control, he'll be able to 'dial in' the Advent tweeter level pretty precisely (sorry for the alliteration).

And two Advent tweeters are likely to be far less expensive than the E-Wave route. Additionally, the Advent tweeter approach maintains an all-70's-vintage Boston-area cone/dome design heritage (no horn/waveguide), if that is of any importance to you at all.

Either way, correctly refoamed AR-2x woofers in clean cabinets with good grilles and logos is a heck of a nice starting point for some good speakers.

Steve F.