Consumer Reports May 1970 Loudspeaker Tests and Rankings

Treker

Super Member
Back when I was a kid my mom subscribed to Consumer Reports and almost religiously followed their “Best-Buy” and “Check-Rated” recommendations over the years. My mom passed away in 2008, but back a few weeks ago while helping my dad go through some of my mom’s old stuff I came across her collection of old Consumer Reports, dating from about 1966 up through 1981, the year I graduated from High School. I started thumbing through them and noticed that it seemed like just about every other issue contained at least one test of something hifi or audio related. But I got to thinking about it, and it made total sense. If you pick up a Consumer Reports today, virtually every other issue will have a report on HDTVs or smartphones, the items that people are purchasing in great numbers today. It's just that back in the '60's and '70's, the consumer item being purchased in great quantities happened to be hifi audio gear. And today we are reaping the benefits of all those hifi purchases back in the day with the bounty of vast quantities of vintage audio gear available at very reasonable prices. As I sorted through my mom's stack of old Consumer Reports issues, I decided to save all of the audio related issues as I thought that some of this material might be interesting for discussion here on Audio Karma.

Now I know that people have various opinions as to the validity of CU’s recommendations and testing methodology, (I personally feel it is very good), but our family had very good luck over the years with the products we purchased based on their rankings. In fact, a large reason I am into hifi today is due to this particular issue of Consumer Reports; the May 1970 issue and its included test of Loudspeakers. In this issue CU rated the Dynaco A25 a “Best Buy,” which my mom used to help justify my parent’s purchase of a pair of these wonderful speakers in 1971. These were the speakers that I grew up listening to, and they were my very first exposure to quality hifi equipment, which in my late teens I would grow to love. But regardless of your opinion of CU and their publication, Consumer Reports, I think many will find this article interesting. I have included a PDF version of the complete article at the bottom of this post. For now I will quote a few selected sections from the article, but I would really recommend reading the whole thing in order to evaluate their comments in their full context.

LOUDSPEAKERS

“Loudspeakers start at about $30 and can run as high as $1000. But past experience has convinced CU that one needn't spend anything like the top price for high quality. Indeed, very few stereo enthusiasts could afford to invest $2000 for a pair of speakers. On the other hand, we have also learned that loudspeakers priced much under $80 are unlikely to deliver the deep bass response needed to reproduce sound with high accuracy. Thus, we decided to build this test program around models in the general area of $80 to $150.”

“CU’s latest tests indicate that loudspeaker quality presently available is very high indeed. Five of the 19 compact speakers tested merited a check-rating. Those were the Dynaco A25, the ADC 303AX, the Scott S15, the AR2ax, and the KLH Six. Two of those – the Dynaco A25 at about $80 and the ADC 303AX at $100 – are judged Best Buys. CU considers the check-rated models high-accuracy loudspeakers. And we were happy to note that all the also-rans could be termed medium-accuracy speakers – no clinkers in the group.”

“Testing: a complex problem
Whenever loudspeaker testing is discussed, two strongly opposed schools of thought usually emerge. Many engineers believe that by using the right tests and interpreting them correctly, speakers can be rated on the basis of laboratory measurements alone, just as can amplifiers, turntables, and other kinds of audio equipment. High accuracy in a loudspeaker, after all, is simply (or not so simply) the precise duplication of the electrical input signal to a corresponding acoustical wave form. Others say that the performance of a loudspeaker is too complex to be thus pinned down and that none of its measurable aspects take into account the listener’s personal likes and dislikes or widely differing room acoustics. Therefore, this group contends, tests and Ratings give no real clue to what any specific buyer will decide is a ‘good’ speaker.

Over the years, CU has constantly refined its testing methods and examined repeatedly the relationship between measurable factors and listeners’ judgments on quality. From such studies, we arrived at two conclusions. First, loudspeaker quality, as the listener finds it, can be measured in the lab, but only roughly – to divide speakers into broad quality groups of the kind used in our Ratings. Second, we found that, except for rare instances, three main characteristics determine how a speaker will sound: 1) The ‘frequency limits,’ or the highest and lowest tones the speaker will effectively reproduce; 2) the ‘spectral energy distribution,’ or the way in which the sound produced by the speaker is distributed within the frequency limits; 3) the ‘time delay accuracy,’ a measurement of whether tones reach the ear with the same relative timing they had when fed into the speaker. (A speaker with time-delay distortion tends to blur the attacks and decays in music.)”

“Analysis of the listening panel’s findings indicated that they judged as most faithful to the reference sound those speakers that had showed up best in the objective laboratory tests. However, the panelists could make no significant ranking inside the quality groups they easily picked out. Thus, both the objective and subjective tests divided our speakers into general quality groups, but did not distinguish between the quality of speakers within the groups.”

“To say that the check-rated models are equal in overall quality (power considerations aside) is not to say that they all sounded alike. Each has an individual characteristic sound. Were you able to make a comparative listening test of the check-rated speakers, chances are you would like some better than others. In order to have an accurate and fair listening test, you must listen to the speakers under identical conditions.”

“A person’s audio memory is notoriously short, so direct comparisons are a must.”

“The ultimate test will be how a speaker sounds at home, so by all means try to get return privileges.”

“When you get your speakers home you’ll have to decide where to place them. Placement can be very important, especially in how much bass the speaker can produce.”

And now, the rankings:

ACCEPTABLE – HIGH ACCURACY
The following loudspeakers were judged to be relatively free of sound coloration and to have the best combination of wide sound range and smooth response.

DYNACO A25 – Check Rated and a Best Buy

ADC 303AX – Check Rated and a Best Buy

Scott S15 – Check Rated

AR2ax – Check Rated

KLH SIX – Check Rated

ACCEPTABLE – MEDIUM ACCURACY
The following loudspeakers were judged to be below the preceding models in overall quality and to have sound coloration that was noticeable but, in general, not necessarily unpleasant.

REALISTIC OPTIMUS 1

EMI 92

SHERWOOD SR5

JBL LANCER 44

EV NINE

LEAK MINI-SANDWICH

ALTEC MADERA 892A

FISHER XP7B

The following loudspeakers were judged to be sound reproducers of medium accuracy but somewhat below the preceding models in overall quality; sound coloration was more noticeable.

WHARFDALE W40D

YAMAHA NS15

JENSEN TF3B

ALLIED 2370

LAFAYETTE CRITERION 5XA

UNIVERSITY LAREDO

This article also included a review of the Bose 901 system, as well as the Harmon-Kardon HK-50 speakers. Speakers that CU called of “Special Interest.”

Now, many of these speakers and speaker manufacturers I was familiar with, while a couple I had never heard of, for example the University Laredo and the Leak Mini-Sandwich (Wow! What a name for a set of speakers!) I was just curious if anyone else has ever heard of these speakers and can comment as to their audio characteristics.

I was also wondering if any of the other speakers mentioned in this report are worth a listen. I am intrigued by the ADC 303AX speakers, as I personally was not aware the ADC ever even made speakers. I have always thought of them as primarily a phono cartridge company.

This is my first post based on these salvaged CR issues. If this information proves interesting to the people here on AK, I will post additional articles in the future. There are lots of reviews of other speakers, receivers, turntables, and phono cartridges from what many consider the Golden Age of Audio that may be of interest.

Edit: 12/8/12: The 2nd post in this series, "Consumer Reports July 1973 Medium-Priced Loudspeakers Test and Rankings", can be found here: http://www.audiokarma.org/forums/showthread.php?t=486249
 

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I know people are going to savage the ratings based on their favorite speaker not getting a good rating. However I'm more interested in the other information, impedance, sensitivity, 1/2 loudness, size and weight. Yes, I'd like to see more articles especially on speakers. I would note in passing that some classics such as the Dynaco A25 and KLH6 did get good ratings.
 
I know people are going to savage the ratings based on their favorite speaker not getting a good rating. However I'm more interested in the other information, impedance, sensitivity, 1/2 loudness, size and weight. Yes, I'd like to see more articles especially on speakers. I would note in passing that some classics such as the Dynaco A25 and KLH6 did get good ratings.

If you download and read the PDF version of the complete article, I think you will find that it includes much of the information you are looking for. I just didn't feel like typing that much. :)
 
With all the speakers I've had through this place, still a pair of ADC 303AX in storage waiting for attention. Wish I'd kept my A25s sometimes. I really liked them.

The Dynacos are absolutely worth a listen. I think the 303s may be fantastic with a recap. The values for the caps are on here somewhere. I'd have to look. The caps are buried in black goo and I could never make out the values printed on them, so finding that would be key. They would probably benefit from a tweeter upgrade. I think they'd be great Econo-wave candidates, or a maybe a Morel MDT 20.
 
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Wasn't that the review that the Bose bozos sued them for? I used to read those reviews through multiple times as a teen, dreaming about one day owning the top-rated gear. My parents subscribed for years. I still subscribe today. The reviews aren't nearly as in-depth today.
 
With all the speakers I've had through this place, still a pair of ADC 303AX in storage waiting for attention. Wish I'd kept my A25s sometimes. I really liked them.

I have 2 pairs of A25s currently, and I love them both. One pair is the original A25s that my parents purchased back in 1971. I recently restored them with new caps, woofers (One was blown. I wonder how that happened? ;-)), new Dynaco logos, and a cabinet refinish. They sound and look as good as new! It's amazing that 40 year old speakers can sound this good. Those speaker designers and engineers back in the day really knew what they were doing.

You should pull the ADCs out of storage and give them the attention they deserve. I'd love to see and read a report about how they sound. If they are as good as this CR article makes them out to be, you may not be missing your A25s all that much after you get them going.
 
And now, the rankings:

ACCEPTABLE – HIGH ACCURACY
The following loudspeakers were judged to be relatively free of sound coloration and to have the best combination of wide sound range and smooth response.

DYNACO A25 – Check Rated and a Best Buy

ADC 303AX – Check Rated and a Best Buy

Scott S15 – Check Rated

Hmmm. I have the Dynaco A25 and also the Scott S15. Not sure the Scotts measure up to (or near) the Dynacos... but.

Maybe I'll give them another listen.
 
I have 2 pairs of A25s currently, and I love them both. One pair is the original A25s that my parents purchased back in 1971. I recently restored them with new caps, woofers (One was blown. I wonder how that happened? ;-)), new Dynaco logos, and a cabinet refinish. They sound and look as good as new! It's amazing that 40 year old speakers can sound this good. Those speaker designers and engineers back in the day really knew what they were doing.

You should pull the ADCs out of storage and give them the attention they deserve. I'd love to see and read a report about how they sound. If they are as good as this CR article makes them out to be, you may not be missing your A25s all that much after you get them going.

Well done getting the A25s back in shape!

I suspect you're right about the 303s. The bass is just fantastic. It's been a while since I listened to them, but I recall thinking the low end was AR5 good, maybe better. Just looking at the tweeter, it makes you think it could be improved, but mine so clearly need caps that I haven't really heard them. I've heard little cone tweeters that really surprised me. I remember recapping and foaming some speakers for a friend - maybe some JBL of non legendary status - with phenolic ring tweeters. I didn't expect much but was pleasantly surprised when the work was done. They sounded really good!
 
And now, the rankings:

ACCEPTABLE – HIGH ACCURACY
The following loudspeakers were judged to be relatively free of sound coloration and to have the best combination of wide sound range and smooth response.

DYNACO A25 – Check Rated and a Best Buy

ADC 303AX – Check Rated and a Best Buy

Scott S15 – Check Rated

AR2ax – Check Rated

KLX SIX – Check Rated

Is that last one supposed to be KLH model six perhaps? I used to have a pair of those too and really liked them.
 
Is that last one supposed to be KLH model six perhaps? I used to have a pair of those too and really liked them.

I expect that it is, but I typed it exactly as it appeared in the original article. I didn't try to make any corrections.
 
Well done getting the A25s back in shape!

I suspect you're right about the 303s. The bass is just fantastic. It's been a while since I listened to them, but I recall thinking the low end was AR5 good, maybe better. Just looking at the tweeter, it makes you think it could be improved, but mine so clearly need caps that I haven't really heard them. I've heard little cone tweeters that really surprised me. I remember recapping and foaming some speakers for a friend - maybe some JBL of non legendary status - with phenolic ring tweeters. I didn't expect much but was pleasantly surprised when the work was done. They sounded really good!

I am of the same opinion. Until you have replaced the caps in these old speakers, you have not really heard them as the designers intended. This became very apparent to me after I recapped a pair of KLH Model 20s. There was a night and day difference in how they sounded. Caps are cheap. Give your 303s a new set and see how much they improve. I would do just one first, and then A/B test them against one another. The recap made a HUGH difference in my KLHs, but the improvement was much more subtle with my A25s. It was an improvement though.
 
Weren't the AR2ax already getting old by 1970?

They may have been. CR always purchased the items they tested on the open market. There was more than one time when one of their "Best Buys" ended up as a discontinued model by the time their report about them was published.
 
I have a pair of ADC 303AXs that my dad bought in 1973 (ironically enough) on the strength of a CR review. They've been in daily use since then without a break. And they still sound great -- I haven't touched them. I thought there must be some sound quality degradation over the years, so when I picked up a pair of reconditioned Altec Lansing Model Fives for the music room system, just for laughs I did a side-by-side A/B comparison. Well, there is no comparison -- the 39 year-old untouched ADCs walked on those Altecs. Frequency response, lack of distortion, crispness of highs, nice tight lows -- the ADCs were superior in every way imaginable. All this with a ten-inch woofer, no mid and a paper cone tweeter. CR got this one right. What a great little speaker. Wouldn't sell mine for a thousand bucks.

Had some A-25s too. They were pretty good ...
 
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Great article. I love reading about the old stuff. It would have been great if they could have gone more in depth, like someone said about 1/2-volume response (and lower), since a lot of speakers were designed for that instead of all-out, top-end performance (like how some cars are designed to cruise while others are designed to scream). I agree that I've always loved consumer reports, but I always wanted a monthly CR specifically-dedicated to audio. I mean, how much audio ground can they cover when they still have to cover every other commonly-associated topic under the sun? Not really their fault.

I was surprised to read what they said about the AR3a, especially since they loved the AR2ax. A guitar-playing friend of mine has a pair of AR2ax's. Great little speaker, and the right size for a bookshelf, I might add. Some bookshelf speakers are just too-small IMO. I even wish the AR25 was bigger. I like the A25 a lot, but it's definitely not designed for pedal-to-the-boards performance. It's a cruiser...

They didn't seem to like the W40D all that much (They best not be saying that about my W90's though :D ), although I didn't quite get the review. "Uneven response, gradual rolloff below 300hz, with a sharper dropoff below 90hz, and moderate rolloff in highs above 10,000hz, not a serious definciency". Well, what's that supposed to mean? Rolled-off bass and highs that start to roll off above 10,000hz? And then they also said the Altec Madeira had a "slight weakness in bass, moderate exaggeration in mid frequencies, and considerable weakness in mid and upper highs", but they didn't say anything about "uneven response", so how do I interpret that. That's why I said I wish there was a Consumer Reports strictly for audio gear (And don't say "Stereophile".... You guys know what I'm talking about).

Also, they picked a "reference speaker" and then made a one-track master-tape recording of that speaker in an anechoic chamber, and if the review-speaker doesn't sound exactly the same as the recording of the reference speaker in the anechoic chamber, then it's not as good? What?
 
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Snip!

They didn't seem to like the W40D all that much (They best not be saying that about my W90's though :D ), although I didn't quite get the review. "Uneven response, gradual rolloff below 300hz, with a sharper dropoff below 90hz, and moderate rolloff in highs above 10,000hz, not a serious definciency". Well, what's that supposed to mean? Rolled-off bass and highs that start to roll off above 10,000hz? And then they also said the Altec Madeira had a "slight weakness in bass, moderate exaggeration in mid frequencies, and considerable weakness in mid and upper highs", but they didn't say anything about "uneven response", so how do I interpret that. That's why I said I wish there was a Consumer Reports strictly for audio gear (And don't say "Stereophile".... You guys know what I'm talking about).

In some of their speaker reviews in the later ‘70’s and into the ‘80’s they started including a response curve along with the ratings. I wish they had done that here. It just seems easier sometimes (at least for me, anyway), to see information like this presented in a graphical format as opposed to just trying to make sense of a written description.

Snip!

Also, they picked a "reference speaker" and then made a one-track master-tape recording of that speaker in an anechoic chamber, and if the review-speaker doesn't sound exactly the same as the recording of the reference speaker in the anechoic chamber, then it's not as good? What?

I think you may have misinterpreted what they were trying to do with this part of the test. From the way I took it they were just trying to establish if listening tests by a panel of real people with real ears would collaborate their laboratory tests. They found that they did. To quote, “The panelists were asked to judge which one of the two test speakers produced a sound that was, overall, closer to that of the reference. (We could, of course, switch back and for the between the reference speaker and the test speakers almost instantaneously.) The listeners were told emphatically not to base their judgments on which speaker seemed ‘better’ for music or which they ‘liked’ better, but merely to say which was more faithful to the reference sound.”

Now I just wonder what they used for their “reference speaker” that “we knew provided a wide, smooth frequency response.” They never mention what it is, but that is a speaker I would love to search out and listen to myself.
 
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