ALESIS ProActive 5.1

May 1, 2004 12:00 PM, By Rudy Trubitt

When a salesperson showed me the Alesis ProActive 5.1 surround speaker system, I was intrigued. I used to have a surround setup in my living room, but a roaming toddler and tipsy speaker stands were a risky combination, so I was seeking a worthy replacement. The ProActive speakers are small enough for easy wall mounting, and the fully integrated controller meant I didn't need to buy a new receiver. I figured I could leave my existing stereo music system intact and use the ProActive system just for surround.

This Alesis-branded product is actually an OEM (original equipment manufacturer) version of the Z-680 system designed and manufactured by Logitech. Logitech sells their $399 list version through computer stores and other consumer outlets. Alesis's version is available at musical instrument and pro-audio stores. For the extra cash, Alesis throws in heavier gauge speaker wire and a free subscription to a surround magazine.

The ProActive 5.1 system includes a subwoofer cabinet containing amplifiers for all six speakers: the sub, three front satellite cabinets, and two rear satellites. An AC cord and hefty heat sink occupy the subwoofer's rear panel. The side of the subwoofer has a bass port.

The brains of the system is a controller tethered to the subwoofer with a nonextendable 4-foot multipin cable. A small infrared remote lets you adjust most settings from across the room. Alesis provides a 6-channel analog audio cable (RCA-to-⅛-inch stereo miniplug) as well as six RCA-to-¼-inch adapters.

MASTER CONTROL

The master controller sports a large knob that adjusts overall volume or the currently selected parameter (Input Select, Level, Effect, Settings, and Mute). Parameters are cycled by repeatedly pressing front-panel buttons.

Coaxial and optical digital inputs and six analog line inputs (using three stereo ⅛-inch minijacks) are supplied on the controller's rear panel. The front panel has a stereo ⅛-inch aux input and an ⅛-inch headphone output. You choose the source by pressing the Input button. Anything connected to the front-panel input jack is mixed into the front left and right channels along with the direct 6-channel analog source. You can use the front-panel inputs for a karaoke input or to overlay system alert beeps from a computer. However, all inbound analog signals are muted when either digital input is selected.

Once you've chosen the input source, several playback options are available. The Effects button actually selects one of many decoders: Dolby Digital, DTS, MPEG, Dolby Pro Logic II Music, ProLogic II Movie, 6-channel analog input, Stereo ×2, or Stereo.

Dolby Digital and DTS will come in handy for watching DVDs or monitoring surround mixes that are encoded into either of these formats. Pro Logic II is the current version of Dolby's 2-channel surround playback system. You feed Pro Logic II a stereo mix, and the decoder derives center and surround information automatically. The center-channel speaker is used in Pro Logic II Movie mode; in Music mode, it is not. (Music mode also includes a number of surround processing parameters not available in other modes.) Stereo ×2 simply puts the same stereo mix in both front and rear speakers, and Stereo is plain old stereo. It's a long list of options, but happily, the system makes the correct choice automatically when it sees a digital input signal.

PRODUCT SUMMARY
Alesis ProActive 5.1 surround speaker system $499
FEATURES	4.0
EASE OF USE	3.0
QUALITY OF SOUND	2.5
VALUE	4.5
RATING PRODUCTS FROM 1 TO 5
PROS: Good value. Fun for home theater. CONS: Poor sonic integration between sub and satellite speakers. Coarse parameter adjustments.
Manufacturer
Alesis tel. (312) 821-5000 e-mail info@alesis.com Web www.alesis.com

BALANCE ISSUES

Each of the satellite cabinets holds a single 2.75-inch speaker. This driver starts working at about 150 Hz; by about 200 Hz you're fully out of the subwoofer and into the satellite. Performance is crisp in the midrange, aiding dialog intelligibility, but not especially detailed in the top octave. No polar plots of the speakers are provided, but I believe that the high-frequency pattern narrows considerably at upper frequencies.

Although the center-channel cabinet is larger than the other four, it also houses a single driver. If you stick your face up to the center-channel speaker, you can hear a low-level hiss while the system is idling, but I never noticed this while playing program material.

The 8-inch subwoofer can put out a clearly audible 40 Hz signal and has plenty of thump. Unfortunately, I was never able to get a completely satisfactory balance between the subwoofer and the satellites; the adjustments you can make to the sub's level are too coarse. In two completely different acoustical environments, I had to set the sub to its lowest possible volume. One more click down, and the sub turns off entirely! Also lacking in any parameter adjustments are useful measurement units such as decibels or milliseconds.

Aside from the sub/satellite balance problem, bass management is handled appropriately and transparently. For example, when operating in direct 6-channel input mode, all low frequencies directed to the five satellites end up in the subwoofer output along with the signal sent to the sub channel. Automatic low-frequency signal routing is an advantage of an integrated 5.1 system such as the ProActive.

The documentation is adequate, although light on placement and calibration details. I created a test CD with band-limited pink noise (500 Hz to 2 kHz) at a level of -20 dBFS RMS, as described in Tomlinson Holman's book, 5.1 Surround Sound: Up and Running. I then calibrated the system levels using that source to video reference (78 dB) and later to film levels (83 dB SPL, C weighted at the listening position). Playback was loud and clear in both cases.

The system is THX certified as a multimedia device (for use, it's suggested, with a computer at a distance of 28 inches). Details of THX's measurement criteria are proprietary and, unfortunately, not available to customers or members of the press. However, I believe that the multimedia criteria is a less demanding spec than the more rigorous THX pm3 certification met by systems such as Mackie's HR824 loudspeakers. In other words, the THX label is reassuring, but I wouldn't read too much into it.

ProActive 5.1 Specifications
Audio
Frequency Response (system)	35 Hz-20 kHz
Peak Output Amplifiers	114 dB
Power Rating	62W (satellites); 69W (center channel); 188W (subwoofer) at 100 Hz and 1 kHz
Signal-to-Noise Ratio	100 dBA
Input Impedance	10 kž
Total Harmonic Distortion	<0.01%
Power Consumption	600W (full program)
Speakers
High-Frequency Driver	3" butyl rubber suspension with aluminum phase plug
Low-Frequency Driver	8" high-excursion, low-throw woofer
Input Connectors	coaxial; optical; 6-channel direct (three stereo miniplugs); analog stereo mini
Crossover
Crossover Frequency	200 Hz
Enclosure
Material	satellites and center: ABS plastic; subwoofer: MDF
Dimensions	satellites 4.0" (W) × 5.0" (H) × 3.5" (D); center 8.5" (W) × 4.0" (H) × 3.0" (D); subwoofer 12.0" (W) × 12.0" (H) × 14.0" (D)
Weight	51 lb. total

SCREEN SOUNDS

Most of my surround work involves the creation of natural and other soundscapes rather than music. I reviewed some of my DVD-A multichannel projects through the ProActive's analog inputs, and the soundtracks translated fairly well. I also listened to some of my recent raw field recordings and generally found the midrange accurate, but felt a gap between the low mids and the boomy, high bass of the sub. One advantage of this extra low end is that if you test your mix on the ProActive 5.1 you probably won't overlook any unintended low-end rumble. If it's there, you'll hear it loud and clear.

A few minutes of DVD playback from the extended version of Lord of the Rings: The Fellowship of the Ring illustrates the system's strengths and weaknesses. Starting at Disc 2, Chapter 4, as the fellowship marches from Rivendell, we hear a fully orchestrated version of the “Fellowship Theme,” culminating with a rich brass climax. Through the ProActive, the track exhibits plenty of midrange clarity, but a lack of airiness. The low end of Gandalf's following voice-over (“We will march 40 days…”) feels a little truncated, indicating a bit of a disconnect between sub and center channel through the crossover range. But moments later, the system shines. While Gimli the dwarf dismisses an approaching flock of birds as just a wisp of clouds, the score signals otherwise. The muted strokes of an orchestral bass drum are delivered with ominous authority by the ProActive sub. Then, as the evil birds swoop in from the rear-right, the listener is enveloped in wing beats and squawking — a wonderful sequence well served by the loudspeaker system.

I had a couple of hardware problems following my purchase. (Skimming the Web, I found a handful of users with similar complaints.) After my initial setup, the system began blowing fuses, so my dealer provided a replacement system. However, the new sub developed a mechanical internal rattle around 110 Hz. Both issues were resolved. The popping fuses seem to be attributable to an early version of the master controller, and have since been fixed. Alesis will repair any rattling subs, but before you call tech support, be sure that the noise you hear isn't coming from objects on, near, or even across the room from your sub.

FINAL CUT

After living with the ProActive 5.1 for a few months, I'm pleased with the purchase. The system is an excellent value, easy to set up and operate, and great for listening to soundtracks of DVD movies — I'm still surprised at how much I enjoy these speakers as part of a home-theater setup. Music playback is somewhat less satisfying, so my original 2-channel playback system is still in place.

The ProActive 5.1 system is a good, low-cost way to get started with surround sound. The monitors can be used as a real-world reference — like having a surround system of Auratones. While I wouldn't rely on them as my primary monitors for production work, they're loads of fun as a playback system.

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Rudy Trubitt is a freelance audio producer in the San Francisco Bay Area. Visit him on the Web at www.trubitt.com.