Bose LifeStyle 12 Home Theatre System
Some years ago, Bose Corporation introduced an unusual loudspeaker system called the Acoustimass 5, which used two small satellite speakers and a separate bass module. Although the basic configuration was not new, the degree of miniaturization and the quality of sound embodied in the Bose system set the Acoustimass 5 apart from earlier attempts to provide good sound from small and reasonably priced speakers. Since that time, the line has been expanded to include smaller satellite speakers and to improve the bass performance.
The Acoustimass speaker family has continued to expand and diversify and now includes home theater configurations using the cube satellites for left, center, and right speakers and an Acoustimass bass module for all the low frequencies. Following that lead, Bose most recently introduced the Lifestyle 12 system, designed for home theater applications.
The Bose Lifestyle 12 consists of five satellite modules, a bass module that also contains the system's amplifiers and surround decoder, a control center, and a remote control. Each satellite speaker consists of two roughly cubical blocks about 3 inches square and 5 inches deep, each containing a 2.5-inch driver. The two parts of each satellite can be rotated independently in order to aim their outputs in the desired direction.
The Lifestyle 12's control center is the same one used in some of the two-channel Lifestyle systems. This compact, lightweight unit (which shows little external evidence of its function) contains the AM/FM tuner, CD player, and preamplifier stage. It has a small display panel and several buttons that control the system's basic operation.
In most cases the Lifestyle 12 system will be operated from its remote control, which is as unconventional in its design as the rest of the system. The all-white remote (with only twenty-one buttons) has absolutely clear and unequivocal black markings and controls the operation of a full five-channel home theater system. Its functions include switching the system on and off, selecting the input source (AM, FM, tape, CD, video, auxiliary), controlling overall volume and the balance between front and surround channels, fast scanning or track selection on a CD, FM or AM tuning or preset channel selection, setting the speaker mode (two-channel stereo, stereo with center channel, or full five-speaker surround operation), temporary muting, and an Auto Off feature that automatically turns the system off after a delay that can be set in multiples of 15 minutes.
The Lifestyle 12's bass module, in contrast to its other components, is large and heavy. It contains the surround decoder and the amplifiers not only for itself but also for the five satellite speakers, and it distributes the signals to them. Long cables are provided to connect the control unit to the bass module and to connect that to the individual satellites. Except for separate treble and bass level trimmers, there are no user-accessible controls on the bass module.
As much as possible, we tested each part of the system separately, taking the output signal from the Tape Out jacks. For speaker measurements, we injected the test signals at the auxiliary input jacks. For listening tests, we placed the five satellite speakers on stands or shelves, as appropriate. The bass unit was on the floor near the front wall of the room, oriented as suggested in the instructions.
The FM tuner characteristics were good, with channel separation exceeding 40 dB over almost the entire audio range. Capture ratio was exceptional, and the image rejection and altemate-channel selectivity were better than average. On the other hand, the AM response, as on almost every home receiver, was restricted at both ends of the spectrum, being down 6 dB at 160 Hz and 2.4 kHz.
The CD player response was flat within 0.7 dB from 15 Hz to 20 kHz, and its interchannel phase shift was insignificant. Channel separation was considerably less than that of most separate CD players, probably because the signal went through the tape-monitoring section of the control unit instead of directly to the output jacks (as on every separate CD player). It was, nonetheless, more than adequate for subjectively perfect separation. Perhaps for the same reason, the CD distortion was higher than usual, though its typical level of about 0.15 percent or less at all levels and frequencies is hardly anything to be concerned about.
The low-level linearity of the CD player's digital-to-analog (D/A) converters was also perfectly satisfactory, within about 1 dB or less of ideal from -60 to -80 dB and only -1.4 dB at -90 dB. In keeping with its emphasis on ease of use, the Lifestyle 12's CD player does not offer the rather complex (and, I suspect, rarely used) programming modes that are usually provided in today's separate component CD players. You can, however, play the tracks on a disc in random order by simply pressing the forward and reverse track stepping buttons simultaneously. Another convenience is its side-mounted miniature stereo headphone jack.
We placed the front satellite cube speakers on stands about 38 inches high, 2 to 3 feet from any walls and 9 feet apart. The bass module was placed between the speakers, about 6 inches from the wall. Although all measurements were made with this normal stereo placement, for listening tests we also put the center-channel speaker between the two satellites, about 5 feet high, and the surround speakers on a shelf 6.5 feet high near the back of the room.
Preliminary listening showed that (in our room, at least) the bass balance was optimum with its level set to the control mid-point, and we listened at that setting. The bass adjustment range was +5 dB around that point, which should be adequate for most rooms.
We measured the room response with a swept warble tone, which yielded a response flat within +/-5 dB from 100 Hz to 8 kHz, with a rising output at higher frequencies. Splicing the bass response to this curve resulted in a composite response of +/-5 dB from 50 Hz to 8 kHz and from 15 to 20 kHz. Between 8 and 15 kHz the output rose an additional 2 dB, but in that range the absorption by room boundaries and furnishings could easily have a greater effect than that, in either direction.
The close-miked response of the bass module showed a maximum at 55 Hz, falling off at about 30 dB per octave below that frequency. Above 55 Hz the output dropped off 10 to 12 dB in the first octave and more steeply at higher frequencies. It seems likely that in some rooms the relative placement of the bass and satellite speakers could introduce a hole in the response somewhere between 100 and 200 Hz. That is a potential problem with subwoofer/satellite speaker systems in general, although we have not found it to be audibly troublesome in this system or others we've tested.
We also made quasi-anechoic MLS frequency-response measurements of a single cube satellite at a 2-meter distance. The on-axis response was unusually flat, varying only +1.5 dB from 300 Hz to 12 kHz.
We measured the bass module's distortion at a typical (fairly loud) level setting corresponding to a 90-dB sound-pressure level (SPL) at 1 meter. It was less than 4 percent from 55 to 200 Hz, a satisfactory result from the standpoint of a music listener.
All these laboriously derived measurements merely confirmed what our ears could appreciate in a few minutes of listening, which was that the Lifestyle 12 sounded quite good indeed. Gadget-happy audiophiles who thrive on the "bells and whistles" of so many of today's components may actually be disappointed with the Lifestyle 12's almost overwhelming simplicity of operation, but just about anyone else is likely to find that one of its most appealing qualities. The system comes with a special test CD for setting the surround balance and a Telarc sampler CD to satisfy the eager owner that it can do justice to well-recorded music.
Personally, I was impressed both by what I heard (and measured) from the Lifestyle 12 and by how simple and intuitive it is to operate. But simple as it is, reading the comprehensive manual is at least as important for this system as for any other.
Although the Lifestyle 12 is designed primarily for use in a complete home theater system, I did not use it with any video sources. But playing my library of Dolby Surround encoded CD's left no doubt of the system's ability to extract the encoded information and put it where it belonged. The Bose Lifestyle 12 is an impressive demonstration of what can be achieved by an unconventional (even iconoclastic) approach to system design.
