JBL L110 Bookshelf speakers

James B. Lansing and his company's successive designs of JBL loudspeakers have occupied a special place in the American audio scene for many years now. So far as the speakers are concerned, their fame has perhaps spread more extensively world-wide in their professional role than m the smaller domestic hi-fi versions. The popularity of JBL speakers with large numbers (but not all) of professional recording and sound reinforcement engineers can be attributed to two special features which are usually present: high power-handling capacity and the high efficiency which can convert large amounts of electrical watts into spectacular quantities of acoustic energy. There are JBL speakers that can fill the largest cinema or pop festival with sound, and other models designed to meet even the wildest (and sometimes aurally harmful) demands of today's pop record producers.

Not surprisingly, therefore, the JBL factory near Hollywood which I visited recently is largely given over to building heavy-duty drive units, including bass drivers with magnets almost too heavy to lift and middle and treble drivers in which getting rid of the surplus heat at high power levels is almost as much a problem as designing for appropriate directional proper ties and exceptional amplitude and velocity in the moving parts. The JBL domestic speakers will also handle above-average power levels, but earlier versions that came over to Europe were generally judged to produce colouration or an excess of presence when used at modest domestic listening levels.

The JBL L110 is part of a new generation and, though it weighs a substantial 23kg (50lb), it is described as a "bookshelf system". The three drive units are mounted in a vertical line, which is desirable for good stereo imaging - but only if the cabinet is placed upright. Laid on its side, which might seem more natural on a bookshelf, the units then appear spaced along a line in the important horizontal plane, and stereo might then be less clearly defined. All this may not seem terribly important, but I should also mention that the line of three drive units is offset about 1-1/2 inches to the right of the cabinet centre, so that problems of symmetry might arise whether the boxes are stood vertically or horizontally.

This small quibble over, it is impossible to do anything but admire this speaker construction. The heavy enclosure is made of dense particle board veneered on four sides with American black walnut. Acoustic damping material is applied to all interior surfaces and the bass unit is reflex loaded via a circular ducted port. This 250mm (10-inch) driver has a 76mm (3-inch) copper-ribbon voice coil, edgewound to put more coil material in the field of the 3.4kg (7-1/2lb) magnet assembly and so improve efficiency and transient response. It crosses over at 800Hz to a 130mm (5-inch) mid-range unit which is housed in a sub-chamber to cut down interference. Frequencies from 4,000Hz upwards are handled by a 25mm (1-inch) dome tweeter also capable of handling high powers and designed to give wide dispersion up to very high frequencies. Thus the -6dB points are said to include an angle of 150° at 15kHz and 90° at 20kHz, which is pretty good.

There are separate level controls in the tweeter and mid-range sections of the dividing network, permitting a considerable degree of adjustment of "brilliance" and " presence", either to suit personal taste or compensate for heavy absorption or over-brightness in the given room. Instead of knobs, these controls simply have a slot for turning with a coin or screwdriver. I approve of this idea, since it makes the controls inconspicuous and subtly implies that they are for occasional rather than frequent use. They are in any case on the main baffle board behind the black grille cover which has a light frame and push-on studs. The cloth has been deliberately made almost transparent so that the drive units are not quite invisible.

How they performed

There is no "normal" marked setting on the two level controls, only a ring of dots, and so I began my listening with what I judged to be central settings. I was soon in no doubt that these JBL speakers do cover a very wide frequency spectrum and can be wound up to very loud volumes without distress, in terms of distortion. Efficiency is about average for speakers of this size so that a modest 10 watts per channel could theoretically be used to give more than adequate loudness in a small or medium-sized room. However, I have implied that JBL speakers are best known for their ability to handle and deliver high powers and so I feel too small an amplifier (or room) would be a misuse of this particular model. The system is rated at 75 watts continuous programme, and an amplifier with this sort of output would be advantageous.

I found that the centre control positions produced a forward, and slightly hard, tonal balance compared with other speakers in my test set-up. Experiments soon persuaded me that the solution was to take down the treble very slightly and the mid-range quite a bit. The balance could be played with in this way to suit very nearly any taste-in fact the tweeter and mid-range can be turned off completely. What helps the impression of improved warmth and naturalness from the L110 compared with earlier JBL speakers I have tried is the smoother and more extended bass end. Even so, my experiments with the level controls did not discover a setting at which all traces of hardness could be eliminated on most types of classical music. This became less of a problem at higher listening levels, as bass was then subjectively firmer, and loud pop music had a special degree of clarity that would surely impress fans of disco music, etc.

Perhaps I can sum up my impressions of the JBL L110 by describing it as the best attempt I have come across so far at bringing the JBL philosophy of high clarity, high levels and plenty of presence from the professional monitoring field into the domestic market. Certainly the so und volume produced can be high enough for all conceivable home or club uses. Yet for modest volumes on classical music there are several smoother and more natural speakers on the market, and in any case the price of £607.50 per pair would seem to put this particular model firmly in the discotheque or clubroom bracket.