Acoustic Research: power hungry?

I have a pair of AR5's I use to as stands for sculpture, not music.
They tend to go through their surrounds but those are an easy replacement.
They tend to burn out their tweeters very easily since they pre-date tweeters with thermal cooling for the voice coils. The level pods get very noisy as well.
Overall, they look a lot like an 8 ohm version of the AR3a but do not sound the same for various reasons. My Dahlquist DQ-10's blow them away in the sound quality department and I expect many of today's reasonable cost speakers out perform them in many ways.

Richard.

 

That's a very vague answer..but I appreciate you answering.

 

The pots just need to be cleaned. The difference between the 3a and the 5 is the woofer. The woofer in the AR-3a is a 12 inch, and in the 5, its a 10 inch, the crossover points are the same. I have never burned out an AR tweeter, and I play them loudly with an amp that is 200 watts per channel. The smoothness in response is unmatched by todays speakers. Yours just need some crossover work. The caps are 30 years old!, and if they sit, unused, they deteriorate. My AR-2's have been in use since the day they were purchased in 1959, and they still play like new.

 

Sorry, I will be a bit more detailed.

A few years ago, I thought the same thing as Richard Feirstein, that todays speakers could surpass the classic AR speakers in many ways. I had had my grandfathers AR-2's, and I loved them, but I thought with todays technology, there would be something better. I went to various Hi Fi shops, and listened to many speakers. The only ones that I kind of liked were the Klipsch Heresy, because they were acoustic suspension, but they lacked the depth of my AR-2's. I also sort of liked some of the upper end B&W stuff, but they all lacked the punch of my old AR-2's. I do not like sub-woofers, I like all of my sound coming from one place. I listened to some other brands, which I cant remember now, the were all ported, and sounded ported. I can hear the air rushing in and out of the port, during heavy bass passages, and I don't like that. I also listened to some new Tannoys, they did not satisfy me either. They all lacked what my AR-2's have. Deep, tight, powerful bass, silky smooth midrange and realistic highs. Most of the speakers I listened too were to forward sounding, way to bright, the upper end response was not flat at all. The AR's have ruler flat response, with the exception of a slight bump in the 100hz range, and thats what I like, smooth response. My budget for speakers was about 5k for a pair. I left the hi fi shops with nothing. I decided that there was nothing like my old AR's. I use my AR-2's as monitors in my studio, powered by a 125 watt per channel Adcom amp. I spend about $300 to restore a pair of AR-3a's, that now sound gorgeous, with no pot issues. I replaced the pots with new L-pads that will not corrode, and I replaced the capacitors with nice new ones. The system has everything I want, powerful, tight bass, silky smooth mids, and realistic, non-irritating highs. I also have a pair of little AR-4x's that I use in my portable system. The 4x has an 8 inch woofer, and a 1 inch tweeter. The AR-2 has a 10 inch woofer and two 3 inch cone tweeters. The AR-3a has a 12 inch woofer with a dome midrange and a dome tweeter.

I would love a pair of AR-5's to complete my vintage years, AR collection, but I don't really have the money right now. Someday...

 

The AR-2 series and the AR-3 series are my favorite. The AR-5 is next. The AR-4x is my favorite small speaker.

 

Actually, AR knew of the AR3a's and AR5's limitations. The inability of the tweeters to withstand high level input without burning out and the steady rolloff of the high end. (Their commercial explination was that this emulated the natural response of a music hall with its high end attenuation).

The AR LST was the answer. It was likely the first speaker that truly met the criterial for the mastering studeo; truly flat frequency response and great dynamic range. Give those a listen if you every come across a pair. Don't get me wrong, I loved the AR line of speakers and stuck with that brand until I purchased my Dahlquist DQ-10's which blow them all away in the sonic department; but were too large and too limited in dynamic range to make it in today's market.

Richard.

 

I believe that AR speakers are rated at 4 ohms, which means that they probably dip into the 2 ohm range (or even less) at certain frequency points. Anyone considering AR speakers, and intending to drive them to fairly loud levels, should make sure that their power amp is capable of delivering power at 2 ohms.

 

I use ARs as monitors in my studio, and they have incredible dynamic range. I have never experenced the problems with tweeters burning out. I have powered both my AR-2's up to 200 watts with no trouble, and my AR-3's up to 350 watts with no problems. Dynamic range has always been incredible. I have heard the LST's, and they are indeed very nice. But with new capacitors, and clean pots, your AR-5's will supprise you.

 

I still own a pair of AR 10 pie speakers, though the drivers need replacing. Back in the day I used to crank these babies up and they'd snort like you wouldn't believe. Sounded quite nice too.

ninohernes, would you have any idea what it would likely cost me to re-do the drivers in my 10 pies?

 

Give Miller a call, he specializes in AR woofers, and his prices are great too! The cost depends on the size of the drivers, and what has to be done to them.

Millersound
1422 Taylor Road
Lansdale PA 19446
Phone (215) 412-7700
Fax (215) 412-0542

 

Very true. The AR-3, 3a, 9, and LST were 4 ohms. They do dip down into the 2 ohm range. For maximum dynamic range, and minimal distortion, you need a very clean, dynamic amp.

 

Joe, thanks for the link. There is lots of great stuff there. Unfortunately it seems like there is not too much info on the AR-2a's. As I mentioned earlier I inherited these speakers from an uncle about 20 years ago. I hooked them up once but the tweeters did not seem to work. I assume this is likely pot related as the pots are very rough. In fact of the mid pots doesn't move at all. Would you reccomend replacement or cleaning?

The serial numbers of these 2a's are 38904 and 45096. It appears they made quite a few of these speakers.

These were the first hi-fi speakers I ever heard, but I never heard anything other than classical music on them and then at lower levels only. I was only a kid at the time (1962) so was not allowed anywhere near them. A few years later my dad got some Lafayette accoustic suspension speakers which he claimed were the same as the AR's. Well perhaps in principle they were, but in my opinion they were vastly inferior in every way. Of course he hooked them up with extremely thin speaker cable so he could tuck the wires under the carpet.

My first experience with pop music on AR's was around 1968. I was at a friend's house and his dad had a pair of AR's. I don't recall which model these were, but they had 10" or 12" woofers. When I heard the bass from Bernadette by the Four Tops, I was totally blown away. I had never heard anything like that before.

I got my first AR speakers in 1970 and they were AR-6's. I think they were only around 70.00 each, but I absolutely loved them. At that point I realized that my goal was to save enough money to get a pair of 3a's. They were a lot of money so it took me a while.

I finally got my pair of 3a's in 71 and they were everything I wanted, though a bit ineffecient. I didn't have enough power (70 watts per channel) to play them really loud. I traded them in 3 years later for a pair of RTR-280's with the matching electrostatic tops. At the time I felt the RTR's were a significant improvement over the 3a's, but if I were able to compare them today I might disagree. The RTR's definitely played louder and seemed to have wider frequency response. Does anybody remember those speakers?

After another year or so I traded for a pair of Dahlquists DQ-10's which I still use today. I still love the DQ-10's. I am running a pair of DQ-1W woofers with them. There is a type of 3D magic that come out of these speakers which I have not heard elsewhere. Of course they do not have the worlds greatest dynamic range.

As a results of your posts, I now am planning on restoring my 2a's back to working order. How do the 2a's compare with the 2's?

 

Many thanks, Joe.

Oh, and AMEN to "Long Live Analog"

 

lil.fred, don't be too scared off. I'm running AR-3a's with a Dynaco ST-70, and with the volume up about halfway on my pre, it's about as loud as I can see myself ever wanting to play it.

 

The AR-2 is a two way speaker system with a 10 inch woofer and two angled, 3 inch tweeters. The 2a is a three way speaker system with the same woofer, two angled 3 inch midranges, and a dome tweeter. The system sounds excellent, but it was discontinued after about a half a year, and replaced with the 2ax. The reason being is, that the midrange units were terribly unreliable, they failed within the first few weeks of use. AR offered an AR-2a to 2ax upgrade at the factory, for a minimal cost. The 2ax used a new midrange. But not to worry, if yours have made it this far, you most likely have a good set, because the failures were most common within the first few weeks of use. To get your speakers working, I would suggest replacing the pots on the back. To access them, you must remove the woofer, pull out the fiberglass stuffing, and then you will see where they are mounted. Be very careful when removing the grilles of the speakers, they are glued and stapled down. The grilles on the 2 series were never made to come off. Also, when re installing the woofer, you must make sure that it is air tight. When you press in on the woofer, it should return slowly, if it jumps back, your seal is bad.

As for a sonic comparison, the AR-2 and the AR-2a are both very natural, smooth sounding speakers. The 2a is a bit brighter than the 2, but the bass response is identical. The 10 inch acoustic suspension woofer is capable of producing very deep, low distortion, convincing bass.

 

I remember as a young man lusting after LST's.

 

Steve summed it all up yeaterday night. As always, let your ears be the judge, listen for music and magic, not sound and specs.

 

Specifications have their place - you just have to know where that is.

 

Here is the LST sales pamphlet.
I also have a copy of the detailed technical specs of the AR-3a, if anyone wants to see them, they are outstanding! But as we said before, lets let our ears be the judge, not the specs.

 

"...it is doubtful that we have come any closer to musical reality than we were in 1960...What does this say about our technological advances and our competitors claims to have perfection within their grasp?"

Competitors?

I did get the feeling that I was reading a sales brochure from a tube amp manufacturer!

 

Joe,

What procedure would you use to remove the grilles. I've heard of people using heat guys before to melt glue. Any specific type of tool to pry with. Where are the staples located?