by Edward Tatnall Canby
ON THE THEORY that one diagram is worth a column of words, I spent a lot of time
recently on my hands and knees in my New York apartment, taking measurements-see
diagram. There you will find my own solution to a major problem these days, how
to cram four channels of sound into a crowded, ill-shaped urban apartment. Most
people still think it is impracticable.
Far from it. In fact, it took me less time to find the right place for four small speakers in my zany and unsymmetrical apartment than it did to make the diagram, unaccustomed as I am to public drawing. It is a sure thing, I say, that if we don't get four channels into thousands of urban apartments like this, we might as well give up, because urban America is America, at least indoors.
For a long time, I've had a hunch that this problem wasn't as bad as most people think. When Electro-Voice recently turned up with a new small-space, big-bass speaker designed expressly for this type of situation, I acted fast. I borrowed four of the Interface: A units, which come in pairs, and hauled a quadraphonic receiver down from the country to plug them into. My four-way solution, as per picture, came after a series of trials in various temporary positions--and I hasten to add that you must do this first, before you get into arguments about furniture and decor. Nine times out of ten, there will be no need to do heavyweight moving. Rather, it's likely to be a change of tables, pictures, lamps, and chairs, no more. But the right place, you must understand, is going to be vastly better than the wrong and thus worth the effort.
I put the front speakers where, years ago, I had found the only workable location for stereo in that same addle-shaped room. I tried them all. You will note that the back speakers, like the front, occupy positions of approximate room symmetry, in a highly lopsided area. It is a first principle that one never places pairs of speakers in grossly unsymmetrical locations-say, one with a wall or corner behind it and the other with a big space behind. It will not work. Don't even try. On the other hand, even a barely approximate symmetry, as between that small corner niche, where my right back speaker is (former telephone table location!), and the corner next to the kitchen, opposite, where the left speaker is, can work out astonishingly well. The little niche made all the difference, as I specifically found out.
For three positions, as marked, I achieved a spacious and listenable quadraphonic sound, though you might not believe it. From the recessed couch (1), actually a bit behind the back speakers, the effect is splendid though the left channel is partially in acoustic shadow and the right is rather close. Fortunately, the Interface: A speakers have excellent sound dispersion, so that you must walk right up to one of them before the sound is heard separately. Mark of a good quadraphonic reproducer. From the center of the space (2), I can do my favorite walk-about listening, on foot. There's just room to move in time to the music without bumping into a channel. As for the day bed, it is sonically out of bounds. I don't listen in bed.
From my work desk in the semi-alcove near the entrance door, I hear a reversed image via reflection. By no stretch could this be called discrete quadraphonic-but I find it pleasant even so, and better than it ever was in stereo from the same place. More info, even if scrambled.
I had long previously found that the placement of the front (stereo) speakers at the edges of the flat overhead arch, with space behind them, greatly enhanced the forward sense of distance and fullness of sound as one listens from the main part of the room. Now, that big space is drawn in and around the back speakers to include the whole listening area. I could ask for no more.
As for the E-V Interface: A speakers, they did indeed fit right into this arrangement. They are of a new, little shape, only 14 by 22 inches and so shallow, only eight inches deep, that you can back them inconspicuously near a wall at the back of a table or other support where, with their neat black grille covers, they blend right into the background, out of the way. No need to make separate furniture lumps out of them.
The units were designed as an updated, computer-calculated, optimum juggling of a number of ingeniously combined principles for maximum bass in minimum space-an honorable and ancient idea. Inside there is a tuned system for efficiency (I noticed this immediately) and a passive front radiator which, in effect, replaces a body of air larger than the box could hold, for correspondingly-increased bass range. Also, there is an equalizer unit, one (stereo) for each pair of speakers. It adds 3 dB of bass boost, with a bottom cut-off to avoid rumble and shake.
Now, I, along with plenty of other hi-fi people, have always distrusted electronic boosting of this sort. It is not the ideal way to get bass, which might be said to be the Klipschorn way, for one. But corner Klipschorns do not into an apartment fit, especially one with 10 mini-corners like mine.
I found that E-V's very modest 3 dB boost was gentle in action and introduced no audible musical problems for my ears. Moderation is a good principle.
One problem, though not E-V's fault. The equalizer units, two for quadraphonic, must be inserted before the main amps and thus use the familiar record-out and monitor-in system, through pairs of connecting cables. (There are extra ins and outs to take your other equipment.) So for just plain phono, I hooked in 10 signal cables and four power cords in an unsightly mess of wire dangling behind my equipment table. Suppose I were to add tape, plus Dolby, Burwen or dbx, plus an outboard demod or decode unit? All use in/out monitor jacks, and the wire tangle would be monstrous, even dangerous. Aaargh!!!
(Source: Audio magazine, Aug. 1975, Edward Tatnall Canby)
= = = =