AR-4x full specs?

[Guest J_R]

I finally decided after years listening to "good enough" speakers to purchase a pair of the classic AR speakers I've been hearing about for so long. But drat... it seems like even on eBay, a decent set of 3a or 2ax models are still just a little beyond my reach, so I went for what seemed the next best choice: My new old 4x speakers will be arriving this week. In the picture they looked to be in pretty decent shape. The serial numbers, which I guess are necessary to pin down cross-over specs, are:

FX 199781 and FX 199807 (only 27 units apart, which is nice)

Before I start tearing into the grills, refoaming (I hope not, at least for a while), replacing fiberglass and tweaking capacitors I'm hoping someone can provide a full set of specs for the 4x. I've searched the CSP library, this forum and the whole bloody internet and while I've found that kind of detailed info (with the frequency response charts and all) for almost every other AR model from the pre-Teledyne years, the ad or spec sheet for the 4x just doesn't seem to be out there.

If it isn't available on line, but someone has a hard copy of it, I'd be glad to pay for a xerox and postage.

Thanks!

-- JR

[Guest J_R]

Naturally, an hour after I post my initial message I finally find a single-page AR-4x ad available from "vintage-ar" on ebay ...(and yes, it *does* have a picture of Judy Collins on it...). I've ordered one, but it doesn't look like it has any frequency response chart or terribly much in the way of detailed specs on it... so my original query still stands.

-- JR

[Carlspeak]

>I finally decided after years listening to "good

>enough" speakers to purchase a pair of the classic AR

>speakers I've been hearing about for so long. But drat... it

>seems like even on eBay, a decent set of 3a or 2ax models are

>still just a little beyond my reach, so I went for what seemed

>the next best choice: My new old 4x speakers will be arriving

>this week. In the picture they looked to be in pretty decent

>shape. The serial numbers, which I guess are necessary to pin

>down cross-over specs, are:

>

>FX 199781 and FX 199807 (only 27 units apart, which is nice)

>

>Before I start tearing into the grills, refoaming (I hope not,

>at least for a while), replacing fiberglass and tweaking

>capacitors I'm hoping someone can provide a full set of specs

>for the 4x. I've searched the CSP library, this forum and the

>whole bloody internet and while I've found that kind of

>detailed info (with the frequency response charts and all) for

>almost every other AR model from the pre-Teledyne years, the

>ad or spec sheet for the 4x just doesn't seem to be out there.

>

>

>If it isn't available on line, but someone has a hard copy of

>it, I'd be glad to pay for a xerox and postage.

>

>Thanks!

>

>-- JR

The 1971 brochure in the AR area of the speaker library mentions the existance of a 'technical data sheet' for AR4x, but none seems to be present in the library. Perhaps John O. may be able to help. He has vast knowledge of that particular model.

Pg. 20 of the above brochure does mention a xover point of 1200 hz for the 4x if that helps. I don't see much value in response charts though, unless you plan to do before and after upgrading response measurments of your own. F3 will probably be in the 60-80 hz range.

There were a lot of posts some months back regarding the ideal stuffing volume for the 4x. Research the older posts if you plan to replace the stuffing. If it's rockwool (clumpy & grey), replace with OC FG. If it's yellow, re-use it. There was a change during the life cycle of the 4x from rockwool to yellow FG. In any case, wear a mask and gloves when you dig into the box stuffing.

My suggestion is at a minimum, replace the 20 uF cap with an electrolytic or MPP cap and thoroughly clean the pot. If the woofer surrounds are okay and the stuffing can be reused, doing the above and re-assembling will give you the results you desire. I wouldn't expect audiophile sound though. Just as Judy Collin's is doing, they will probably serve very well as background music speakers or, part of a surround sound system.

Good luck and enjoy!

Carl

Carl's Custom Loudspeakers

[johnieo]

My new old 4x speakers will be arriving

>this week. In the picture they looked to be in pretty decent

>shape. The serial numbers, which I guess are necessary to pin

>down cross-over specs, are:

>

>FX 199781 and FX 199807 (only 27 units apart, which is nice)

JR: you will enjoy them. The 4x is still a nice speaker. I will be interested in your speaker's details as they fall in a range where we have no data. We know that serial number 175,000 still had a 1,400 Hz crossover, and that by 225,000 the crossover had been changed to 1,200 Hz. The new crossover used the larger (AR-#5 coil). The date codes on your tweeters and woofers will tell us more about when these changes took place. In this same time range AR reduced the stuffing to increase Q. Yours will have either 18 or 12 oz. Could be FG or could be Rock wool. I have been told and belive it, that rock wool is not as good a heat exchanger as fiberglass; if present, I would replace it with yellow fiberglass. (Rockwool is lumpier, less uniform in size, and has less surface area per ounce than does fiberglass.) Home Depot sells 11 oz. fibeglass "Handy Packs" that will each do one cabinet. However, if your cabinets have fiberglass, no point in changing the material.

There was a third change. The cabinet material was changed from 5/8" to 1/2" veneered stock. The internal dimensions remained unchanged. You can identify yours by measuring the thickness of the picture frame. Alternatively, the older cabinet is 19-1/4" x 10-1/4" x 9-1/4" instead of 19" x 10" x 9" on the newer cabinet, etc...

>

>Before I start tearing into the grills, refoaming (I hope not,

>at least for a while), replacing fiberglass and tweaking

>capacitors I'm hoping someone can provide a full set of specs

>for the 4x.

Pleas tear carefully!! There are six or more brass brads with glue underneath the grille frame. Work slowly. I replaced them with Velcro! Refoaming? NO!!!!!! AR-4x woofers have cloth surrounds!

>I've searched the CSP library, this forum and the

>whole bloody internet and while I've found that kind of

>detailed info (with the frequency response charts and all) for

>almost every other AR model from the pre-Teledyne years, the

>ad or spec sheet for the 4x just doesn't seem to be out there.

Specs and advertisement attached for the new version. These were either placed in the archives or attached to a post by Tom Tyson. The free resonance of the woofer is 30-32 Hz. The system resonance is 58-60 Hz. Great sounding small speaker.

Enjoy! And when you do open the cabinets, we would love to know which crossover/stuffing and their mfg date. (Tweeters usually had ink stamped dates, woofers used YYWW for year - week.)

Cheers

[Carlspeak]

Thanks John for the curves.

Your first two attachments are in the archive. However, the second two are not. Perhaps you could convince Mark S. to get them in there and included in that .zip 1971 file?

It's all about the music

Carl

Carl's Custom Loudspeakers

[Guest J_R]

John and Carl,

Thanks so much, guys... and John in particular for the images of the frequency response charts. How great to have a resident expert on this model on this forum. I realized the 4x was a bookshelf speaker in every sense of the word when I decided to buy a pair. I, wonder, was it pretty much the *first* bookshelf speaker of real quality and so (like other AR innovations) did it define the concept for many years to come? What I was looking for, after 40 years of ever-declining quality mass-market pop speakers for the home, was to try out the thing AR was famous for: accurate and uncolored sound reproduction.

These will be going into my library/office where what I want is good clean sound at moderate to low volume. I have what I think will be the perfect placment for them -- at ear level on the wall across from my desk, where I can give them almost three feet to the side walls and still get decent seperation and distance in relation to the desk chair.

Looking at the charts John provided I am impressed with the woofer... and I now realize they have cloth surrounds on my models. How cool... I think. I've never owned cloth woofers before... do they ever deteriorate like foam? Is there a significant audio difference between cloth and foam surrounds?

Even the overall frequency response looks pretty darn good for *any* bookshelf, much less a 40-year old unit, as my serial numbers indicate a build-year of 1967 or perhaps 1968 -- truly vintage years in so many ways, as those who can will remember. I know that AR improved the tweeter in later models -- while the dispersion on the the 4x was great for the time it obviously really drops off when you move much more than 30 degrees off axis. I know that upgrading the tweeter is a popular option for 4x owners. I'd be interested to hear what anyone has to say about doing this... and not just "on paper" as obviously the specs would be better... but what about the actual listening difference? And is such an upgrade considered verboten by AR purists?

-- JR

[johnieo]

>John and Carl,

>

>Thanks so much, guys... and John in particular for the images

>of the frequency response charts. How great to have a resident

>expert on this model on this forum.

J-R: Tom Tyson is the resident AR historian; the rest of us merely collect his and other folks' data! Carl: The two curves not in the archives were most likely attachments Tom added to one of his posts. That would be the only other place I would have seen those curves.

Let us know how you like their sound; if you do open them (carefully of course!), let us know what you find. Although they did change a model's details, AR didn't do it nearly as often as Detroit!

Cheers,

[Steve F]

JR--

Here is a post of mine from 2005 that you may find interesting:

Steve F Fri Apr-01-05 02:22 PM

Member since Sep 27th 2002

334 posts

#1. "RE: Ar-4x-Archive"

In response to Reply # 0

The 4x created a sensation in the marketplace akin to the impact that the AR-3 had had several years earlier. It was the first so-called compact speaker that could truly reproduce the majority of the audible musical range, and as such, was absolutely unique among its peers. Julian Hirsch said in his test report in Stereo Review that the 4x had a uniform, wide-ranging frequency response that was exceptional by any standards and unheard of for a speaker in its size and price class. Consumer Reports in 1966 said that the 4x’s high frequency response was among the most accurate they had ever tested for any speaker, regardless of price. There was simply nothing like it from any other company, from the time the 4 was introduced in 1964, until, arguably, the Smaller Advent came out in 1970. Even then, the Smaller Advent was a somewhat larger, more expensive speaker, more in the category of the AR-6.

The 4x had an enclosure volume of barely more than .6 cu. ft., yet its 8” woofer produced solid, honest, low-distortion bass easily down to the mid-50Hz range. And the 4x was affordable, bringing the best-in-industry AR performance to hundreds of thousands of music and hi-fi aficionados, thereby helping to usher in the explosive period of mass-market growth of stereo/high fidelity equipment.

I have a strong fond memory of the 4x’s. My Dad had assembled a nice stereo system in the 1960-62 time frame consisting of the Allied Radio Knight Kits pre-amp, 35/35 tube power amp, and tuner, along with a pair of Goodmans 15” 3-way speakers installed in massive 36 x 24 x 16” HWD floor standing enclosures that he’d bought from Lafayette Radio. My Mom very patiently put up with these behemoths for many years, until finally, in 1969, she’d had enough. "I want these beasts out of my house!"

So, my Dad and I went to the local Lafayette store and listened to some Wharfedales, the Dyna A-25’s and the 4x’s. The Wharfedales were ok, but not in the same class; the Dyna’s were excellent, but just a little more than Dad could spend at the time. We came home with the 4x’s, and the salesman had given us the Walnut for the Unfinished price. Such a deal. (That was well before AR became widely discounted through the mail-order houses—and that’s another long story that I have covered at length in past posts.)

When we hooked them up and compared them to the Goodmans, it was a revelation. How could these small boxes, literally one-eighth the size of the Goodmans, sound so much better? Top to bottom, it was no contest. It was the reason that the 4x was such a smash success and also the reason it was such an important historical speaker.

Steve F.

[JKent]

JR

One small thing: John is certainly an (the?) expert on AR speakers, but I've found you may not need velcro to hold the frames on. Friction may be enough if you are replacing the cloth. If you do use velcro, one dot in each corner is probably plenty. I also make a loop out of fishing line--it's virtually invisible and will help you get the frames off later. Prying always runs the risk of damage to the walnut frame. btw--I use my 47-yr-old 4x's as my main speakers thanks to John's expert advice on restoration (and a Cambridge Soundworks subwoofer for those blow-em-up movies)

Kent

[soundminded]

I think what surprised me most was how well it did in the live versus recorded comparison against the 1905 Nickelodeon. It came very close to AR3 which was around 4 times as expensive. I'm surprised after all these years how little understanding there still is about the perception of sound and why KLH model 17 was preferred by many consumers when playing commercial recordings. It wasn't just marketing and the model 17 was more expensive. Somehow limitations of the recordings themselves or the way many of them were made must have had something to do with it.

[Rlowe]

John, here is that link;

http://www.classicspeakerpages.net/dc/dcbo...ing_type=search

However, I couldn't get the pictures to "show".

Subject: "Frequency response of classic AR's, especially the 4x" postjob62 Fri Aug-26-05 01:46 PM

Member since Jun 27th 2005

87 posts

[Rlowe]

John, here is that link;

http://www.classicspeakerpages.net/dc/dcbo...ing_type=search

However, I couldn't get the pictures to "show".

Subject: "Frequency response of classic AR's, especially the 4x" postjob62 Fri Aug-26-05 01:46 PM

Member since Jun 27th 2005

87 posts

[Steve F]

Soundminded,

You, myself, and others have touched on this subject before. It is fascinating that a more "accurate" speaker like an AR might actually sound worse on a commercial recording than a less accurate KLH or Advent.

Perhaps it was partly because of the presence-peaked recording monitors that caused the recording engineers to reduce the upper mids so it would sound good when played back in the studio. This depressed upper-mid recording would then sound "dull" on an accurate AR, but sound more appropriate on a KLH or Advent.

Perhaps it was also that during a fast retail A-B, the brighter-sounding speaker would grab the uninitiated listener's ear and that speaker would be "preferred."

AR's always wore well over time in an owner's home. The sheer number of AR replies on this Forum vs. all the others COMBINED is testimony to the essential correctness of their design.

Interesting, for sure.

Steve F.

[Carlspeak]

"....Steve F is right that AR did not generally publish “system” frequency-response numbers for their speakers, simply because end-users could incorrectly interpret these numbers as the actual “in-room” performance of those speakers. The vagaries of frequency-response numbers have always been questioned, of course, unless the testing was carefully documented, controlled and performed according to standards in a manner that could be duplicated by others trained in this sort of measurement. However, I don’t believe that AR was ever intentionally deceptive in this methodology, or accused of being cynical or deceptive by any of the reputable reviewers and critics of the era. Others with “an ax to grind,” might have felt differently...." [TOM TYSON]

Above is a pasted segment of Tom Tyson's 2005 post referenced in these threads. It's important to note from his text that the curves you seek were created in a very controlled environment, an anechoic chamber, vital for repeatable testing at the time. As Tom notes, many assumed the curves would be duplicated in their own listening room - a highly unlikely event considering basic room modes and a multitude of potential reflections.

Now, jump ahead 42 years. Yup, that's about the age of your 4ax's. Compounding the uncertainty of performance is the shear age of these drivers. Will they perform the same as they did back in the mid-60's? That would be an interesting experiment. Original specs are nice to look at but, do they mean anything today? Who knows?

One saving grace for you is the ability to adjust the tweeter's response which may help you fine tune the sound in that room you have planned for their use. Enjoy, and don't worry about specs.

It's all about the music

Carl

Carl's Custom Loudspeakers

[dynaco_dan]

>Perhaps it was also that during a fast retail A-B, the

>brighter-sounding speaker would grab the uninitiated

>listener's ear and that speaker would be

>"preferred."

A salesman using the treble, bass and loudness to their advantage could make the very finest system sound sadly lacking.

Inversely, they could make a very sad excuse for a system sound much better than something, which we may feel is much superior.

>

>AR's always wore well over time in an owner's home. The sheer

>number of AR replies on this Forum vs. all the others COMBINED

>is testimony to the essential correctness of their design.

>

>Interesting, for sure.

>

>Steve F.

Hi Steve;

You hit the nail on the head.

The number of AR posts does tell a lot about classic AR popularity, at least compared to the other forums here.

With just the last year or so, to look back on, see the increase of membership.

I believe the change in name and it's well deserved reputation, has caused a migration of new members for all of the other forums as well.

Worldwide also, neat.

Mark has added a few more forums, Dynaco for one, and there is an interest there being shown.

Greg Dunn's Dynaco website is really great but there is no forum's or at least it appears to me, no additional updating of equipment profiles or catalogs or manuals.

Never the less, a great site to visit, in my opinion, at least.

I am not saying that this site is like that one, not just yet, but they both can provide information to the world.

A classic hifi library source for the world, albeit, not necessarily every brand maybe.

Dynaco, for just one brand, can build up with time to become a reference point for everyone in the near future.

Even if you take into consideration how many different writers chat on the AR fourum, there is not a large number.

But quality, not quantity, is what this entire website appears to be, to me at least.

Thank you Mark and all of you contributors.

[Kieran M]

Vintage speaker question:

My main speakers are a pair '67 AR-4xs which I absolutely love, a very musically satisfying speaker. I also have a '71 Fender Precision Bass, which Is really the only bass I use for gigs and studio. My question: Does the wood and materials in speakers improve soundwise over time like a vintage guitar gets better with age?

Just another crazy bass player...

[RoyC]

Vintage speaker question:

My main speakers are a pair '67 AR-4xs which I absolutely love, a very musically satisfying speaker. I also have a '71 Fender Precision Bass, which Is really the only bass I use for gigs and studio. My question: Does the wood and materials in speakers improve soundwise over time like a vintage guitar gets better with age?

Just another crazy bass player...

The short answer to your question is "no".

The cabinet is supposed to be as inert as possible. Those old AR cabinets are made of plywood or medium density fiberboard (mdf) covered with wood veneer.

Roy