By EDWARD J. FOSTER
Dimensions: 17 3/4 in. W x 6 1/4 in. H x 17.3 in. D (44 cm x 15.9 cm x 44 cm). Weight: 27 lbs. (12.2 kg).
Price: $2,800.
Company Address: 2201 East Dominguez St., Long Beach, Cal. 90801; 800/536-9663;
Nothing tickles a jaded reviewer's fancy like an original product, one that points in a new direction and seems certain to be imitated. The Kenwood KC-Z1, alias the Kenwood Stage 3 Controller, is such a seminal product. You could call the KC-Z 1 a tuner/preamp because it's certainly that.
You could call it a Dolby Pro Logic/THX Home Cinema processor, for it fulfills those functions too. And you could call it a Dolby Digital (AC-3) processor, because it's that as well-with inputs both for the straight digital AC-3 outputs from sources such as DVD and for the RF-modulated AC-3 out puts from laserdisc players.
But what makes the KC-Z1 innovative is its Touch Panel controller, which is 2 inches thick, just under 5 inches high, and 6 3/4 inches wide. Centered on its front is a 3 1/4 x 3 3/4-inch backlit LCD touch screen. When the controller is docked to the KC-Z1, it obscures the main panel's buttons and knob and becomes the system control panel, communicating with the KC-Z1 via five electrical contacts that also keep its internal battery charged. When you remove it, the TouchPanel communicates with the KC-Z1 via radio frequency (RF) rather than infrared signals; as a result, it can control the KC-Z1 from another room-with in a 100-foot range, according to Kenwood. What's more, the RF communication is two-way, so the TouchPanel's display always shows the KC-Z1's operating status, even if you've changed that status from the front panel.
Removing the TouchPanel leaves a front panel with basic controls for setting volume, selecting a source, muting, and turning the KC-Z1 on and off. In fact, there are two on/off switches: "Remote Power" toggles between "Standby" (which lets you turn the KC-Z1 on from the TouchPanel) and "On"; "Main Power" turns the Kenwood off completely.
At the lower right, under an overhang, are four LEDs: a two-color (red/green) "Battery Charge" indicator for the TouchPanel, a green indicator that lights when a Dolby Digital signal is present, a "THX" indicator that does like wise when Home THX enhancement has been chosen, and a "REF/Peak Level" indicator that flashes green when a source's output level attains THX or Dolby reference level and flashes red when a signal overloads the controller's input circuitry.
The front panel also has a "Page" button that beeps the TouchPanel to help you find it if it's mislaid. That's more important than you might think, because you really need the TouchPanel for full control. It alone enables you to operate the tuner, set sound modes (tone controls, surround, and a good bit more, as we'll see later), and select signals for recording. It can be used as a universal remote to control virtually any audio or video component, and it can set up commands to be carried out at programmed times.
Volume and muting are controlled by three mechanical buttons on the TouchPanel's case; everything else is controlled by … touching different areas of its LCD screen.
When you first insert the TouchPanel's rechargeable battery, you must calibrate the screen to ensure that the touch points map properly. This is done by touching targets that move around the screen. Once the screen is mapped, you're off and running.
At the bottom of the TouchPanel's screen are five permanent icons: "Power" turns the KC-Z1 on and off, "Main" lets you listen to and control all components in your system, "Sound" gives you control over the way the system sounds, "Presets" enables you to save multiple control settings for instant re call, and "Help" tells you how the TouchPanel's pads work in its different screens.
The "Main" menu displays icons for every component in your audio or A/V sys tem. To choose a program source, you simply touch its icon. The icon for the active source has a dark background; the other icons' backgrounds are light. Touchpads at the right of the screen access various sub-menus: "Speaker VOL." for multiroom systems, "Tape 2 Monitor," "Accessories" (for activating up to six accessory devices, such as fans or lights, via learned infrared codes), "Alarm Set" (to activate system presets at times you select), "Setup," and "Record." Some of these submenus are single-layered; others are nested deeply.
With the "Setup" menu's "System" sub-menu, you can set the system clock, get a tutorial of system operations, enter security codes so that no one can tamper with your settings, adjust screen contrast, recalibrate the touch screen, and change the frequency of the RF link between the KC-Z1 and the TouchPanel if there's interference. You can also select how quickly the TouchPanel's battery-saver will turn off the LCD display and how often the KC-Z1 sends status updates to the panel.
You use the "Component" sub-menu to add and remove program sources from the system. It brings up 11 icons, one for each source in put. The icons for components that you've told the KC-Z1 you're going to use have dark backgrounds; the unused ones have light back grounds. Touching an icon puts that source in the accepted list (so it will appear on the "Main" screen). You can then set that source's input level (from 0 to-6 dB) and set up the TouchPanel to control it.
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Fig. 1-Quieting characteristics and separation, FM tuner section.
Fig. 2-Frequency response and crosstalk, FM tuner.
Fig. 3-THD + N vs. frequency, FM tuner.
Fig. 4-Frequency response from CD analog input in "Source Direct" mode.
Fig. 5-Tone-control range and response of subwoofer crossover.
Fig. 6-RIAA phono equalization accuracy.
Fig. 7-THD + N vs. frequency.
Fig. 8-THD + N vs. level, D/A converter section.
Fig. 9-Deviation from linearity, D/A converter.
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Kenwood components that are compatible with the company's SL16 control system can be set up with a single touch; for other re mote-controllable components, you use an on-screen keypad to enter a control code from a seven-page list in the KC-Z1's clearly written owner's manual. (The manual is in two volumes, one for setup and the other for operation.) After that, you can control the selected component from the TouchPanel. The KC-Z1 will send the appropriate control signals to Kenwood SL16 components via "System Control" jacks on the KC Z1's rear panel and send infrared signals to other components via repeaters that you can position facing the components you want to control. One repeater is supplied with the KC-Z1; the rear panel has connections for two more.
The "Sound" pad on the "Setup" menu displays a diagram of a home theater system: a TV screen, a viewer, and five speakers plus a sub-woofer. Active speakers are indicated by a dark background and inactive speakers by a light back ground. Touching a speaker icon calls up a submenu with which you can set its level (the test-tone generator is controlled from this sub-
menu) and delay. All but the left and right front speaker menus carry "Speaker Size" pads. The menus for center and surround speakers offer a choice of "None," "Small/THX," or "Normal"; the "Subwoofer" menu choices are "Normal" and "None." Accompanying the diagram on the "Sound Setup" menu's first level are controls for the KC-Z1's DSP acoustical ambience simulations: "Wall" (with a choice of soft, medium, or hard simulated wall textures), "Room Size" (small, medium, or large), and a five-step "Effect Level" adjustment.
Pressing the printed "Sound" touch point, at the bottom of the "Main" screen, brings up another system diagram. This one has controls for mode selection ("Source Direct," stereo, mono, Dolby 3 Stereo, Dolby AC-3, and Dolby Pro Logic) and processing options ("THX Cinema," "DSP Logic," or "None"). In each mode, the system diagram shows the currently active speakers as solid boxes with shad owed outlines and the inactive speakers as boxes with broken lines.
From this screen you can set each speaker's level and delay, turn a subwoofer-channel bass limiter on and off, and set the allowable peak level at a point that won't overload your subwoofer. Another submenu lets you choose analog, digital coaxial, digital optical, or RF inputs but only where appropriate-"RF," for example, is an option only for the laserdisc input.
Also on the "Sound" menu are pads to operate the bass and treble controls and adjust DSP settings. A "Midnight" submenu lets you turn on medium or high dynamic compression for late-night listening; in Dolby Digital mode it offers "Dia log Normalization," which keeps dialog (but not music and sound effects) at a constant level from disc to disc.
When you select a remote-controllable program source from the "Main" menu, the TouchPanel's screen displays appropriate controls, including track selectors for CD, tuning pads for the built-in tuner, and an alphanumeric pad for entering station frequencies or disc titles.
Because the TouchPanel's graphics vary with the program source, you see only the controls you need. That, to me, is its essential beauty.
The TouchPanel's two potential problems, that you might lose its vital control capabilities by misplacing it or that its batteries might discharge, are solved on the KC-Z1's front panel by the "Page" locator and a compartment that houses and charges a spare battery. A "Battery Charge" LED to the left of the charging compartment glows red when a battery is charging and green when it's fully charged.
-------The TouchPanel detaches for use as a remote.
THE ESSENTIAL BEAUTY OF THE TOUCHPANEL MENUS IS THAT THEY SHOW ONLY THE CONTROLS YOU NEED.
You may well need that extra battery. Al though a full charge is supposed to last for 4 or 5 hours of continuous use (longer in normal use), with the LCD display "sleeping" when not needed, the battery does run down if you leave the TouchPanel un-docked for long periods of time. The battery is a Duracell DR-17 that can be recharged about 250 times; recharging takes 2 to 4 hours.
At the lower left of the KC-Z1's main panel, next to the "Main Power" switch, is a small panel that slides open to reveal the "Video 3" input's S-video connector and gold-plated composite-video and audio RCA jacks. All other connections are on the rear panel. The 70-odd analog and digital connectors here reflect the KC-Z1's capabilities. There are 10 sets of analog inputs alone, not to mention the "Video 3" connectors on the front and the built-in tuner.
That should be sufficient to satisfy the wishes of the most enthusiastic audio/video aficionado.
There are analog audio recording out puts for two tape decks, a MiniDisc deck, and "Video 1" and "Video 2," so you can record with as many as three audio decks and two video decks, depending on what you've selected from the TouchPanel.
The laserdisc input and all three video inputs have composite and S-video jacks, as do the "Video 1" and "Video 2" recording outputs and the output for a video monitor.
The TV, "Cable/SAT," and CD inputs have just audio and composite-video jacks. The provision of video for the CD input is per haps in anticipation of DVD players, which will also reproduce audio CDs. One might argue that an S-video input is at least as appropriate for a DVD player and a DBS receiver as for a VCR or laserdisc player.
The laserdisc input has three "AC-3" connectors for Dolby Digital Surround.
One jack accepts the raw RF signals from the AC-3 outputs on laserdisc players. The other two, one optical and one coaxial, will accept ordinary stereo PCM signals or Dolby Digital bitstreams from sources that sup ply the bitstream directly, such as DVD players. This arrangement lets the laserdisc input serve as an S-video-equipped DVD connection. Dolby Digital signals from a cable or satellite decoder are expected to be in digital form and enter via the AC-3 "Cable/SAT" coaxial or optical connector.
Coaxial and optical digital connections for the CD input and for the MiniDisc input and recording output are also provided.
The coaxial digital inputs and eight out put RCAs (six for home theater plus a pair to send audio to a second room) on the back panel are gold-plated; the rest are base metal. In addition to the six output RCAs, a DB-25 connector can be used to feed all six channels to a similarly equipped multi channel power amp through a single cable.
Rounding out the complement are the two SL16 "System Control" jacks, connectors for the three infrared repeaters, wire clamps for an AM antenna, an F connector for a 75-ohm FM antenna, and three switched convenience outlets (200 watts maximum total power).
Measurements
I've stopped expecting great performance from the FM tuner sections of A/V receivers and tuner/preamps; since the yen soared, tuner sections have hit the skids. So, by current standards, the KC-Z1's tuner is comparatively good in most respects.
As Fig. 1 reveals, the FM tuner section's 50-dB-quieting sensitivity (23.8 dBf in mono, 44.4 dBf in stereo) is par for the course today, even though tuners were routinely 6 dB more sensitive a few years back. Ultimate quieting is admirable, almost 74 dB in mono and better than 68 dB in stereo with a signal strength of 75 dBf or more. Both of these measurements (and the noise plots of Fig. 1) were taken on an unweighted, albeit band-limited, basis.
As you can see in Fig. 2, channel separation (about 38 dB or more over the important audio range) is good, too, but FM frequency response droops substantially in the bass (-1 dB at 50 Hz,-2.5 dB at 30 Hz, and about-4.75 dB at 20 Hz).
Total harmonic distortion plus noise (THD + N, Fig. 3) is probably somewhat better than average for to day's tuner sections, though I can remember when 0.25% distortion at 1 kHz in mono (almost twice that in stereo) was nothing to write home about.
Capture ratio (see "Measured Data") was good, and selectivity was reasonably decent, which suggests that the KC-Z1 will acquit itself well in the presence of multipath. Had the AM rejection been better than 35.9 dB, however, I'd feel a lot more confident of that assertion. Image rejection was rather poor, which probably won't concern you much unless you live near an airport. Stereo FM pilot and subcarrier rejection were okay but no great shakes.
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Fig. 10-Fade-to-noise test, D/A converter.
Fig. 11-Frequency response, D/A converter.
Fig. 12-Frequency response in Dolby Pro Logic mode (A) and with THX Cinema enhancement (B).
Fig. 13-THD + N vs. frequency, Dolby Pro Logic mode.
Fig. 14-Frequency response, Dolby Digital mode.
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Turning to the preamp section's analog inputs, I measured frequency response through the analog CD input in "Source Direct" mode and also in regular mode.
Figure 4 shows the Kenwood's response only in "Source Direct." (There was little difference with the tone controls engaged and set to "Flat.") The response is +0, -0.25 dB from 20 Hz to 20 kHz (within the limits of measurement error), and the-3 dB points are below 10 Hz and at about 100 kHz. Fine performance! Figure 5 illustrates the integral sub-woofer crossover's characteristics and the maximum range of the bass and treble con trols. The tone controls shelve the bass be low about 150 Hz and the treble above 10 kHz. Their ranges are symmetrical, just over ±10 dB at 100 Hz and 10 kHz. The subwoofer crossovers occur close to the
Home THX-specified frequencies and have the THX-required slopes, 12 dB/octave on the high-pass filter and 24 dB/octave on the low-pass.
The KC-Z1's RIAA phono equalization error (Fig. 6) is fairly small; phono response fits within a 0.5-dB window. However, the phono input impedance could not be modeled by a classic parallel combination of resistance and capacitance, which could affect a cartridge's frequency response. Sensitivity was fine for a moving-magnet cartridge, and S/N for this input (and for the analog CD input) was very good.
On the downside, the phono and CD analog inputs overloaded at precariously low levels. The overload point varied with volume setting, abruptly tripling as I lowered the volume setting from +7 to +6. Be cause overload determines the maximum output level available from these inputs, I omitted output voltage at clipping from "Measured Data." (However, the KC-Z1 can deliver more than adequate output to drive any power amplifier to distraction!) The KC-Z1's THD + N at 2 volts out and 12 dB of voltage gain (Fig. 7) is less than 0.005% across the band for the CD analog input. It's less than 0.075% (probably more noise than distortion) for the MM phono input. Third-octave noise spectra (not shown) seemed fairly ordinary;
the noise rose at 3 dB/octave (modified by the RIAA equalization in the phono spectrum) over most of the audio band. There were a few power-line related components, mainly at 60 and 180 Hz. A trace of power-supply hum appeared at 120 Hz in the CD plot, but it was negligible.
The THD + N plots in Fig. 7 also include measurements made on the main-channel D/A con verters for signals from the digital CD input. I was surprised to find the D/A converter distortion so high. The numbers themselves aren't all that bad (less than 0.074% from 20 Hz to 20 kHz), but that's about 20 times worse than the performance of the KC Z1's analog circuitry and far worse than is typical of today's DACs. The DAC's THD + N versus level at 1 kHz (Fig. 8) tells a similar story. Distortion over the top 10 dB of the range is much worse than normal, which forced me to use an expanded vertical scale to accommodate the data. As the graph indicates, however, distortion is pretty low from-20 dBFS down.
The DAC's 1-kHz linearity curves (Fig. 9) are likewise reminiscent of bygone days.
Again, I had to expand the vertical scale to accommodate the converter's substantial low-level nonlinearity (almost 5 dB at -90 dBFS and almost 7 dB at -100 dBFS). Based on this data, I expected the results for the fade-to-noise test would be quite poor; strangely, however, they're quite good. Figure 10 shows the plot taken on the right channel; the left was a trifle better. I repeated the linearity and fade tests several times and came up with consistent results, but I'm at a loss to explain why such similar tests yield such different data.
The frequency response of the DAC and its attendant circuitry (Fig. 11) is not dead flat, as such curves usually are these days, but it's reasonably good. Worst case, it's +0.26,-0.11 dB from 20 Hz to 20 kHz.
The DAC's A-weighted noise was a low -107 dBFS. Spectrum analysis revealed no sign of sampling-frequency leakage and extremely low power-line-related hum.
Quantization noise (more important than A-weighted noise) and dynamic range (measured in accordance with EIAJ standards) were also admirable. Channel separation was decent (better than 55 dB) but about 10 dB poorer than separation for the analog CD input.
Frequency response for the KC-Z1's Dolby Pro Logic decoder section is shown in Fig. 12: Fig. 12A is for plain-vanilla Pro Logic, while Fig. 12B was made with the Kenwood's THX Cinema enhancement. (I omitted the "Center, Normal" curve in Fig. 12B because it adds nothing to the curve in Fig. 12A.) On the whole, the response curves are exemplary. Center response in the "Wide" (full-bandwidth) mode droops a couple of dB at 20 Hz, but this is counter acted by a rise in main-channel response at this point. Apparently there's some cross feed from the center to the main channels in the low bass even when using what Kenwood labels the " Normal" speaker setting (i.e., a full-size speaker) for the center and surround channels. (What's now called "Normal" used to be called "Center Wide," meaning wide bandwidth). Because of the shift from center to main in the deep bass, in "Measured Data" I included the response in these channels from 35 Hz to 20 kHz rather than from 20 Hz. With a "Small/ THX" center speaker (a mode more typically referred to as "Center Normal"), the center channel's-3 dB point was near the 100-Hz target.
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Measured Data
PREAMP SECTION
THD + N at 2 V Output, 20 Hz to 20 kHz: CD input, less than 0.0046%; MM phono input, less than 0.0733%.
Output Impedance: 150 ohms.
Frequency Response: Tone controls by passed, 20 Hz to 20 kHz, +0,-0.27 dB (-3 dB below 10 Hz and at 103 kHz); tone controls at detent, 20 Hz to 20 kHz, +0,-0.25 dB (-3 dB below 10 Hz and at 98.2 kHz).
Tone-Control Range: Bass, +10.7 and-10.9 dB at 100 Hz; treble, +10.6 and-10.8 dB at 10 kHz.
Subwoofer Crossover: High-pass,-3 dB at 82 Hz and-6 dB at 62 Hz (nominal 12-dB/octave slope); low-pass,-3 dB at 66 Hz and-6 dB at 81 Hz (nominal 24 dB/octave slope).
RIAA Equalization Error, 20 Hz to 20 kHz: +0.4,-0.11 dB.
Sensitivity for 0.5 V Output: CD input, 108 mV; MM phono input, 1.27 mV at 0-dB attenuation and 2.53 mV at-6 dB attenuation.
A-Weighted S/N re 0.5 V Output: CD in put, 97.7 dB; MM phono input, 85 dB.
Input Impedance: CD input, 47 kilohms; MM phono input, 48 kilohms resistive (see text).
Input Overload (1% THD at 1 kHz): CD input, 2.24 V for volume settings of +7 or above and 6.75 V for settings below +6; MM phono input with 0-dB attenuation, 26.8 mV for volume settings of +7 or above and 80.5 mV for settings below +6; MM phono input with 6-dB attenuation, 130 mV for volume set tings at or below +6 and 42 mV for set ting of +16.
Channel Separation: Greater than 64.7 dB, 100 Hz to 10 kHz.
Channel Balance: ±0.04 “direct" mode.
Recording Output Level: CD input, 490 mV for 0.5 V input; MM phono input, 410 mV for 5 mV input at 1 kHz; FM tuner, 560 mV for 100% modulation at 1 kHz.
Recording Output Impedance: 405 ohms.
FM TUNER SECTION
50-dB Quieting Sensitivity: Mono, 23.8 dBf; stereo, 44.4 dBf.
S/N Ratio at 65-dBf RF Input: Mono, 73.4 dB; stereo, 65.5 dB.
Stereo Frequency Response: 20 Hz to 15 kHz, +0.18,-4.77 dB.
Channel Balance: ±0.03 dB.
Channel Separation, 100 Hz to 10 kHz:
Left to right, greater than 38.2 dB; right to left, greater than 37.9 dB.
THD + N at 65 dBf for 100% Modulation: Mono, 0.35% at 100 Hz, 0.26% at 1 kHz, and 0.4% at 6 kHz; stereo, 0.57% at 100 Hz, 0.44% at 1 kHz, and 0.97% at 6 kHz.
Capture Ratio at 45 dBf: 1.0 dB.
Selectivity: Adjacent-channel, 3 dB; alternate-channel, 56.8 dB.
Image Rejection: 53.7 dB.
AM Rejection: 35.9 dB.
Stereo Pilot Rejection: 33.6 dB.
Stereo Subcarrier Rejection: 49.4 dB.
DOLBY PRO LOGIC MODE
THD + N at 2 V Output, 100 Hz to 20 kHz: Main channels, less than 0.028%; center channel, less than 0.032%; surround channel, less than 0.27%.
Frequency Response: Main channels, 35 Hz to 20 kHz, +0.6,-0.14 dB (-3 dB be low 10 Hz and at 23.05 kHz); center channel, "Wide" mode, 35 Hz to 20 kHz, +0.08,-0.7 dB (-3 dB below 10 Hz and at 23.05 kHz); center channel, "Normal" mode, 104 Hz to 23.05 kHz, +0.09,-3 dB; surround channel, below 10 Hz to 6.9 kHz, +0,-3 dB.
A-Weighted Noise: Main channels,-92.3 dBV; center channel, "Wide" mode,-96.8 dBV; surround channel,-97.8 dBV.
Channel Separation at 1 kHz: 59.3 dB or greater.
DOLBY DIGITAL (AC-3) MODE
Channel Balance: 0.47 dB or better.
Frequency Response, 20 Hz to 19 kHz:
Main channels, +0.28,-0.11 dB; center channel, +0.17,-0.09 dB; surround channels, +0.23,-0.14 dB.
THD + N at 0 dBFS: Main channels, 0.061% at 1 kHz; center channel, 0.068% at 1 kHz; surround channels, 0.072% at 1 kHz; LFE channel, 11.4% at 30 Hz (see text).
Channel Separation at 1 kHz: Between main channels, 73.6 dB or greater; all other channel combinations, 84.5 dB or greater.
D/A CONVERTER SECTION
Frequency Response: 20 Hz to 20 kHz, +0.26,-0.11 dB.
THD + N at 0 dBFS: Less than 0.074%, 20 Hz to 20 kHz.
THD + N at 1 kHz: Below-71 dBFS from 0 to-90 dBFS and below-93.1 dBFS from-30 to-90 dBFS.
Maximum Linearity Error: Undithered signal, 4.9 dB to-90 dBFS; dithered signal, 6.9 dB to-100 dBFS.
A-Weighted S/N: 107 dB re 0 dBFS for infinity-zero signal.
Quantization Noise:-91.7 dBFS.
Dynamic Range: Unweighted, 93.9 dB; A-weighted, 95.4 dB.
Channel Separation: Greater than 55.6 dB, 125 Hz to 16 kHz
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The KC-Z1's THD + N versus frequency with Dolby Pro Logic (Fig. 13) is very good, as these things go. In the front channels, distortion maxes out at about 0.03% over the range from 100 Hz to 20 kHz. In the surround channel, it's barely more than that from 600 Hz to 7 kHz and remains less than 0.27% down to 100 Hz.
The A-weighted noise was excellent in Dolby Pro Logic mode, around-97 dBV in the center and surround channels and, oddly, a bit worse (-92.3 dBV) in the main channels. Separation at 1 kHz ranged from 59.3 dB (surround to right front) to 87 dB between center and surround. Overall, it averaged nearly 65 dB, which is first-rate.
I measured Dolby Digital Surround operation with a Yamaha CDV-W901 laserdisc player and the Dolby Labs test disc. The response curves are shown in Fig. 14. Worst case, they're within +0.23,-0.11 dB from 20 Hz to beyond 19 kHz. All channel levels matched within 0.5 dB, which is fairly good.
I didn't measure the response of the low-frequency effects (LFE) channel because it clipped severely at 0 dBFS (distortion was more than 11%) even with the KC-Z1's subwoofer level set to minimum. Distortion at 1 kHz and 0 dBFS on the other channels was fairly good, no more than 0.072%.
Channel separation at 1 kHz ranged from a low of 73.6 dB between right and left front to a maximum of 96.6 dB between right front and right surround. For the most part, separation was on the order of 90 dB, far more than anyone needs but impressive nevertheless.
Use and Listening Tests
Although the KC-Z1 performed decently overall in my lab, I'm more impressed with its operational convenience than with the technical refinement of its circuitry. As the lab tests indicate, the Kenwood is not up to snuff in several respects, notably in its D/A converters, Dolby Digital LFE channel, and phono preamp (the least of my concerns).
To see whether I could hear these effects, I set the KC-Z1 up in my home theater, using the Yamaha CDV-W901 laserdisc player as a source. I connected the Yamaha's AC-3 RF link and its stereo feed to the Kenwood's laserdisc input, and I coupled the Yamaha's digital output via a Toslink to the Kenwood's CD optical input. This arrangement should have let me compare Dolby Digital with Dolby Pro Logic, by toggling between the respective modes of the KC-Z1's laserdisc input, and compare the Kenwood's DAC with the one in the Yamaha player, by toggling between laserdisc and CD inputs. Matters proved not quite so simple, however. Like most microprocessor-controlled gear, the KC-Z1 mutes for several seconds when modes or sources are changed, and I couldn't match levels exactly. Therefore, my comparison was not as precise as I would have liked. Nonetheless, I was able to draw a few conclusions.
On music, I preferred the sound of the laserdisc player's D/A section to the Kenwood's. Thomas Labé's Steinway D (Transcendental Bach, Dorian Discovery DIS 80117) had more "air" when I used the analog link than the digital link, and the bell-like quality of his playing and the ambience of the Troy Savings Bank Music Hall were more convincing with the Yamaha's converters than with the KC-Z1's. When I switched to the CD input (and thus to the KC-Z1's internal DACs), the sound hardened noticeably and the notes' reverberant tails seemed rather truncated. To be fair, in the absence of direct comparisons I think many people would be quite satisfied with the KC-Z1's DACs.
I had no cause for complaint with the KC-Z1's home theater performance. Movie soundtracks seem to be fairly immune to minor technical imperfections in playback systems (and those of the KC-Z1 do qualify as minor). Perhaps that's because of the way the soundtracks are mixed; perhaps it's because the viewer/listener becomes so involved in the visual action that he's less aware of subtle sonic details. In any event, I thoroughly enjoyed the KC-Z1 in my home theater, especially when using Dolby Digital mode. Side and rear sound effects were far more precisely placed and more stable and believable in this mode than in Pro Logic.
The outdoor sounds (wind, rustling grass, etc.) and the sword fight in the first 30 minutes of Rob Roy, for example, were great in Pro Logic but spectacular in Dolby Digital.
The opening tornado in Twister was incredible. Interestingly, I was unaware of distortion in the Dolby Digital LFE channel, either because it didn't occur at the levels present on the LFE channels of the discs I used or because it was sonically benign.
Minor foibles notwithstanding, the Kenwood KC-Z1 is a component to be reckoned with. It's remarkably complete and flexible in application, and to call its TouchPanel innovative is the understatement of the year. No longer must you enter your home theater armed with a remote in each hand; no longer need you fumble with a billion-button "universal." The Kenwood KC Z1's TouchPanel nudges you, it guides you.
It's a universal remote made to be used by humans!
(Audio magazine, Feb. 1997)
Also see:
Kenwood KR-6340 "Two-Four" Receiver (Dec. 1973)
Kenwood KP-5022 Turntable (Sept. 1975)
Kenwood KX-660HX Cassette Deck (April 1988)
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