Harman/Kardon AVR 30 AV-receiver
The Harman Kardon AVR 30 is a complete audio/video receiver that would be equally compatible with a stereo music system or a home theater installation. Although none of its five audio-amplifier channels would be considered exceptionally powerful by today's standards, they are conservatively rated, and the receiver's total power capability is more than sufficient for almost any home installation.
In stereo mode, the front left and right channels are rated to deliver 60 watts each, into 6-ohm loads, from 20 to 20,000 Hz with no more than 0.09 percent total harmonic distortion. In five-channel surround mode, the three front channels (left, center, and right) are each rated at 50, watts from 20 to 20,000 Hz with no more than 0.09 percent distortion, and the rear channels at 20 watts each into 4 ohms with less than 0.3 percent distortion.
In the AVR 30's Audio Direct mode, only the front left and right channels are active, and it functions as a conventional stereo receiver. When it is switched out of Audio Direct (with a front-panel pushbutton), the Surround Mode button selects one of the receiver's digital signal processing (DSP) modes, which drive the rear speakers with different combinations of slightly delayed program signal. The surround modes are identified as Pro Logic, Movie, Simulated Surround, Club, Theater, Hall, and Stadium.
For each of these modes, which activate the surround amplifiers and speakers, the initial delay can be set to 15, 20, or 30 milliseconds. For all but the Dolby Pro Logic mode, whose parameters are fixed, the Effects Level buttons vary the level and duration of the delayed signal to produce the desired effect in rooms having a wide range of acoustic properties. A Center Mode button controls the center channel in the Pro Logic and Movie modes, offering a choice of Wide (full-band-width center), Normal (center-channel bass sent to the left and right speakers), or Phantom (when no center speaker is used). Like all Dolby Pro Logic systems, the AVR 30 has a built-in random-noise test signal, for balancing the levels from the various speakers, that switches successively to the left, right, center, and surround channels.
The knob-operated controls of the AVR30 include bass, treble, balance, rear (surround) and center level, speaker-output selection (it can drive either or both of two sets of main-channel stereo speakers, or only the front-panel headphone jack), and master volume. There is also a subwoofer-level knob, which adjusts a full-band-width line-level output on the back panel for driving powered subwoofers.
Large buttons across the top of the panel select AM or FM, with signal-seeking tuning in stereo or manual tuning in mono, and tune up or down in frequency. The display window, in addition to presenting the receiver's audio operating status, shows the tuning mode, frequency, and preset-channel number. Eight buttons store the frequencies of up to sixteen AM or FM stations in two groups of eight (AM and FM channels can be mixed).
The input source is selected by means of two parallel rows of large buttons across the bottom of the front panel. They are identically marked, with the upper row designated listen to and the lower row rec from. An LED in each button lights to show its activation (green for listen and red for record). The AVR 30 provides for a full complement of signal sources, including phono, tuner, CD, auxiliary, TV, satellite, a videodisc player, two VCR's (inputs and outputs), a videocassette player (whose audio and video input jacks are on the receiver's front panel), and two audio tape decks (with inputs and outputs). There is also a Simulcast button, which can be used to record or watch a video program from one of the available sources while listening to or recording an audio program from another source, such as the tuner. At the right end of the row of selectors are a button for loudness compensation and one that converts any stereo audio program to mono.
When the AVR 30 is connected to a video monitor via the Monitor Out jack on its rear panel, the monitor also provides an on-screen menu system for adjusting and verifying the status of most of the receiver's controls. It comes with two remote controls: a system remote control (SRC) and a home theater controller (HTC). The SRC, which has some sixty-seven clearly marked buttons, duplicates most of the front-panel control functions. It includes five keys that simplify operation of the on-screen menu system and has groups of buttons to control compatible Harman/Kardon cassette decks and CD players. The remote can also operate the rear-level and master-volume controls, which are turned by small motors when adjusted from a remote.
The HTC, with only forty-one buttons, controls most of the receiver's basic operating functions, though not as completely as the SRC. Its source selection is also slightly less complete than that of the SRC, but it has more functions related to home theater operation. Harman Kardon says that the HTC is preprogrammed to operate most remote-controlled devices likely to be connected to the AVR 30, even from other manufacturers.
From the rear, the AVR 30 appears considerably less formidable than most comparable receivers. Although it has a full complement of input and output jacks, the size of the receiver prevents its rear apron from having the over-packed appearance of some we have seen. In addition to the inputs (and outputs, where applicable) for its many signal sources, it has line-level outputs for front, center, rear, and subwoofer channels and insulated spring-clip connectors for right and left surround speakers and a center speaker. The two pairs of left and right front speaker outputs use conventional insulated multiway binding posts.
In addition to connections for the supplied AM loop antenna, there are inputs for 300- and 75-ohm FM antennas, all small binding posts. Two small jacks provide for a remote infrared sensor input and an output to other Harman/Kardon components for system remote control. There are three AC outlets, two of them switched.
The performance of the AVR 30's tuner section was, in most respects, typical of today's medium-price component tuners. Its 2-dB FM capture ratio and 63-dB alternate-channel selectivity measurements are good, although its 45-dB image rejection would be considered marginal in a location near a busy airport. We were surprised at the high level of 19- and 38-kHz leakage from the multiplex decoder into the audio. Only 35 dB below maximum program level, it prevented direct measurement of the tuner's total harmonic distortion plus noise (THD + N) in the stereo mode. But a spectrum-analyzer measurement of the significant harmonics showed that the distortion was acceptable-about 0.3 percent at most signal levels, reaching a low of 0.12 percent only at a very high input of 95 dBf (30,000 microvolts). The FM frequency response was good, but the AM tuner, like almost all we have tested in recent years, had a very limited bandwidth.
The receiver's audio control section had a very wide, flat response, down only about 2 dB at 200,000 Hz. The tone controls had a maximum range of about +/-11 dB, with the bass control having a sliding turnover frequency from 300 Hz to below 100 Hz and the treble response curves hinging at about 2,000 Hz. The loudness compensation boosted only the frequencies below 400 Hz, to a maximum of 8 or 9 dB, as the master volume-control setting was reduced. The phono-preamplifier input overloaded at very safe levels.
The front three power-amplifier channels delivered a maximum output of about 70 watts each into 8 ohms and 100 watts into 4 ohms (we did not test them with their rated load of 6 ohms, where the performance would be between the limits of our 8- and 4-ohm measurements). At 50 watts output, the distortion (THD + N) was between 0.03 and 0.04 percent from 20 to 20,000 Hz, and at a constant 0.1-percent distortion the output over that range was between 60 and 66 watts.
Although no useful measurements of the amplifier's various surround modes were possible, we used them for most of our listening. The spaciousness added by the receiver's internal delay and DSP circuits was unmistakable, and quite natural and pleasing if not done to excess. When the Effects level was set too high, however, multiple echoes (particularly of human voices) were clearly audible, producing a most unnatural sound. That is a potential weakness of signal processors that create an insufficient echo density and that have too long an initial delay. Since the few DSP components we know of that do not exhibit this effect happen to cost considerably more than the entire AVR30 receiver, this really is not a serious criticism. With the Effects level set to one of the two lowest available positions, the overall result was highly satisfactory with most material.
Overall, the Harman Kardon AVR 30 is a good value, capable of serving as the heart of a good audio/video entertainment system. It is easy to use, the installation and operating instructions are clear, the performance is good, and the price is right.