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Military audiophiles can now choose from the largest selection of loudspeakers ever
Off Duty / Europe / November 1972 - This Month's Shopper - By THOM PRINGLE

IN SEARCHING for some way to describe loudspeakers this year, there just seems to be nothing as appropriate as the word "exciting". We've used the word in our previous loudspeaker reports - but it still seems to fit better than any other adjective we could find.

First as we've said before, loudspeakers are inherently exciting. There's something about listening to a loudspeaker come to life for the first time that is exhilarating. It's fun to buy the other components, of course, and a real kick to operate them but when the loudspeakers start to perform they're always the show stoppers.

Second, there have been new developments in loudspeakers this past year which have produced some interesting products. New manufacturers have entered the loudspeaker competition; established names in the audio business also have started to make loudspeakers, even though they didn't before, and some of the established loudspeaker manufacturers have come up with new speaker designs. Overall, the competition has gotten much tougher and the general quality of acoustical transducers has improved a great deal.

Our loudspeaker SHOPPER has grown since last year - if you were to make a direct comparison, you'd find that several names and models contained in last year's SHOPPER are missing this year but that even more new names and models have arrived to take their places. Further study will show that a large portion of the new models in the SHOPPER are high-performance "studio" models.

With the spotlight on loudspeakers and the success of the "super" loudspeakers in recent years, many manufacturers have introduced what are called studio-quality speakers. Some of these units are definitely super speakers but what they all have in common is carefully controlled performance parameters - usually including a guaranteed frequency response.

In addition, they can be expected to have very rugged, high-grade components and often are individually checked and calibrated. These studio series speaker systems are becoming quite popular with military audiophiles since these units offer outstanding performance and are available at prices as much as $200 less than the Stateside prices. (Most of the studio series units are selling for between $150 and $400 (each) in military outlets.)

Another idea which has gained apparent acceptance is the sound-panorama or wide-dispersion principle. After enough people had been exposed to the Klipsch and Bose systems, both of which can create exceptionally wide panoramas, there was general agreement that you have to have large sound panels, extra radiators, reflectors or something, but you can't do an effective job with a transducer peeking out the front of a square box.

The result? AR brought out a multi-faced unit, Fisher's studio series has obliquely mounted tweeters, Infinity's Holosonic has tweeters facing five different directions, Micro/Acoustics designed a wide-dispersion add-on tweeter, and so on. These are not omnidirectional nor wide-panorama units but a sort of compromise since many manufacturers claim that a little directionality is necessary for the types of recordings that shouldn't be stretched over a large area. Of course, 4-channel can certainly help ease the problem but even it is in need of help when the front channels are very dominnt.

One trend which is starting to grow now and which you can expect to grow even more in the future involves system speakers. The idea is simple and seems to be quite effective. The manufacturer designs a speaker to give the kind of performance he wants regardless of its input requirements.

When you receive the loudspeaker you also get a plug-in equalizer which you can add to your amplifier by plugging it into the external preamp/power amp junction or the tape monitor circuit.

This circuit alters the frequency response so that the amplifier complements the speaker - attenuating some frequencies and accentuating others. The speaker can then give a uniform output response regardless of its impedance or special design characteristics.

For some time the Bose 901 has used this principle and external systems equalizers such as Altec's Acousta-Voicette and Soundcraftsmen's units have been available.

Now, Altec has introduced a new system speaker called Concept EQ 5, which includes an electronic equalizer, and Electro-Voice has a new model with a similar idea called the Interface: A. Both models claim exceptionally smooth and wide frequency responses.

Also among the new speaker models you will find a fair number of units with electrostatic elements. This reflects the further concern that audiophiles have shown about transient response. Many argue that at high frequencies, only the thin membrane of an electrostatic element can keep pace with sudden bursts of signal that are present in almost any recorded material.

Electrostatic tweeters do react well and have very smooth responses but they also involve power supplies, higher cost and often require large driving powers. Nevertheless, you can expect to see more speakers with electrostatic elements as the demand for more elaborate components increases.

The future for loudspeakers looks good since three of the most important areas - performance quality, sound dispersion and system response - are being actively worked on. In the meantime there are some specific parameters you should become acquainted with in order to enjoy browsing through our 1972 loudspeaker SHOPPER.

In our listings we refer to all models as systems since all the units listed come with a matching enclosure or other ancillary equipment. Individual transducer elements in the systems may be referred to as speakers.

This year in our SHOPPER we have abandoned the traditional bookshelf and floor-standing terms in favor of three categories, small, medium-size and large. Most people choose medium-size units since they may be used in either small or large rooms, whereas small systems are usually limited to small areas and large systems are best used in large rooms.

Most speaker systems have some means of splitting the audio spectrum into two or more parts each of which is then fed to speaker elements especially designed to reproduce a particular range of frequencies.

The result is lower distortion and better frequency response even though there is usually some loss of energy in the frequency dividing network.

There are three types of speaker manufacturers when it comes to frequency response; those who give no frequency response, those who give unreferenced frequency responses and those who give complete frequency response figures.

Manufacturers giving no frequency response (some of the major companies included) argue that the ear should be the final judge and that frequency response isn't important for selection. Ouite frankly, we're in favor of seeing a referenced frequency response statement for a loudspeaker system.

Too often, it seems, the human ear tends to change its opinion or discover shortcomings in a speaker system only after prolonged listening.

Frequency response statements which are unreferenced (do not give variance limits, such as ±4 dB) tell you, at best, what frequency range the speaker is supposed to cover. Very often, these types of speakers will lose over 20 dB of output by the time they reach their stated end frequencies.

Keep in mind, too, that the room where you place your speakers will have an effect on the apparent frequency response - this is where you may want to use the treble and bass controls on your amplifier and speakers.

There are two power ratings which should concern you. The first is the maximum power rating which tells the maximum amount of power you should allow to be put into the speaker system. In some cases, if you exceed this limit you may burn out the speaker units.

In other cases, the manufacturer has found that driving the system above a certain limit seriously distorts the output of the system, therefore making any further increases useless. In any case, try to match the speaker rating to your amplifier so that you will have eliminated any risk.

The minimum power rating given by some speaker manufacturers means that you must drive the speaker system with at least the given number of watts for satisfactory performance.

The impedance of the speaker system should match the output of your amplifier for best performance. Actually, the impedance of most speaker units varies considerably according to the frequency they are reproducing. This variance in impedance is reflected back to the amplifier which may reduce its output power by a considerable amount.

There may be as many as three types of components inside your speaker cabinet although sometimes functions are combined in two units or even one to save space and money.

If you have three types of components in your system, you will most likely have a woofer to cover the low frequencies, a midrange unit to reproduce midrange frequencies, and a tweeter to take care of the high frequencies.

Most all woofers today are cone-type speakers designed to work especially with frequencies from 20 up to 500 or 1,000 Hz. The majority are direct radiator types with some of the big systems using horns to load the woofers for better efficiency. One exception to the cone-type woofer, is the Quad Electrostatic which uses an electrostatic membrane for low frequencies.

Midrange units and tweeters use the same types of transducers; cones, domes, horns and electrostatics. Generally speaking, they all do an equally good job, since the job of creating high frequencies is considerably easier than that of pushing out the lows. One notable exception is the electrostatic transducer which is noted for its exceptionally smooth response in the treble regions.

In addition, you will run across many types of special units such as super-tweeters, upper-bass woofers, etc. This is carrying specialization to a high degree of development and here's a case where you may have to rely on your ears to determine whether it's worth the extra money. Some systems, too, will have separate outside terminals for each internal transducer thus allowing you to use bi-amp amplifier units.

There are many different types of enclosures each with different advantages and drawbacks.

High efficiency enclosures, usually big units or the less-expensive small ones, use reflex arrangements whereby sound from the back of the speaker cone is circulated to the front to add more volume (also called ducted port enclosures) and horn enclosures.

The horn-type enclosures have large horns attached to the front of the speaker units which effectively matches to speaker to the air in the room and provides excellent efficiency.

Low efficiency enclosures (including acoustic suspension types and electrostatic units) are almost always more expensive and require more power to operate. They are typified, though, by their fine frequency response and usual compactness.

We should also mention here the part enclosures play in the reflected-sound idea. With the direct systems, you will find all the sound being directed out the front of the unit, though there may be some dispersion guides to disperse the sound over as wide a range as possible.

In the reflected-sound systems there are several ways in which the sound may be redirected. In some cases a duct is left open in the rear of the enclosure to allow some of the sound to escape out the back, bounce off the wall and create additional ambiance.

Other enclosures have individual speakers mounted on the back of the enclosure, aimed at the wall to give even a higher degree of reflected sound.

The enclosures which make most use of your walls are the ones which actually use the wall as part of the enclosure. You must place these enclosures a specified distance from the wall in order to get the maximum benefit from their design.

Finally, there are the omnidirectional systems, which put out sound in all directions and are usually ball-shaped, cube-shaped or columnar.
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There they are. Loudspeaker systems of all sizes, types and descriptions from the simplest to the most complex. All available to military audiophiles, of course.

Your problem now is to figure out which one is right for you. And, even after you take the size, price and features of the various models into consideration, you'll still probably want to hear your choice before you put down the cash and that's where the listening rooms become important.

Ask to hear several different models - perhaps even some you hadn't considered buying. If you already have a stereo system, take along your own records so you can compare the sound of the speakers in the showroom to what you have at home.

Above all, take your time and think over your decision. You'll probably be listening to it for several years.
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• Anmerkung : Das war natürlich recht weit hergeholt, denn in den großen Audio-Clubs hatten die Hersteller bzw. Distributoren immer einen eigenen Raum, mal größer, mal kleiner, in dem nur die eigenen Produkte vorgeführt wurden. Ein echter fairer Vergleich war für die GIs als Kunden in den seltensten Fällen möglich und auch gar nicht gewünscht. Auch BOSE hat immer nur die 901 vorgeführt, auch auf den deutschen Hifi-Messen und Funkausstellungen.

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