Alesis ProLinear 820 DSP Active Monitor

You've heard the advice about monitoring your mixes on several different speakers. The idea is to hear your mix on a wide-range flat system, a boom box, a car stereo, a portable radio and so on. That way you know the mix will sound good on a wide range of systems.
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You've heard the advice about monitoring your mixes on several different speakers. The idea is to hear your mix on a wide-range flat system, a boom box, a car stereo, a portable radio and so on. That way you know the mix will sound good on a wide range of systems.
Product PointsApplications: Studio, broadcast

Key Features: Two-way; 8-inch Kevlar woofer; 1-inch silk dome tweeter; onboard DSP; onboard 80W LF amp; onboard 40W HF amp

Price: $549

Contact: Alesis at 401-658-5760, Web Site.
It can be a hassle to set up several of these monitors and switch among them. To make things easier, the Alesis ProLinear 820 DSP monitor includes built-in DSP to emulate several models of speakers. It starts with a basically flat response and applies equalization presets to simulate the tone quality of various monitors.


Included are eight factory presets and eight user-adjustable presets. They can be selected either by pushbuttons on the monitor itself or in the supplied graphical software. The software controls the monitors' DSP through a cable plugged into a computer serial port. It works great. You can fine-tune the speaker's response to your listening environment as well. What's more, the 820 is a superb monitor in its own right. Its DSP smooths the response and tightens the signal alignment between the drivers.

A two-way loudspeaker, the 820 includes an 80W continuous power amplifier for the lows and a 40W amp for the highs. The amp features a low-weight switching power supply and driver protection circuitry. The 8-inch ported woofer is made of Kevlar/carbon fabric. With its high stiffness-to-weight ratio, the cone material is said to reduce distortion, extend bass response and provide excellent transient response. Inside the woofer is an oversized, efficient magnet assembly. The 28mm silk dome tweeter is ferrofluid cooled to improve power handling and flatten the response. Both drivers are shielded for use near a CRT.

The dark grey cabinet is heavily braced and internally coated to reduce resonances. Each unit measures 17 inches x 11 inches x 13.5 inches and weighs 32 pounds. On the front are two vents designed to eliminate vent noise, plus an LCD screen and pushbuttons to control the DSP. They are neatly integrated into the front baffle. The LCD screen shows all DSP parameters and flashes red if the speaker is overdriven.

On the back is an XLR/TRS connector that accepts a balanced or unbalanced line level signal. Also on the back are heat-sink fins for the power amp, an AC power cord connector, level control knob, power switch, and in/out serial ports. The supplied cable from PC to speaker, or between speakers, is a standard 9-pin RS-232 serial cable.

As for manufacturer's specs, maximum SPL is 113 dB/W/m and frequency response is 50 Hz to 20 kHz ±1.5dB (typically -3dB @ 39 Hz).

Each monitor's 24-bit DSP includes four programmable, parametric equalizer bands. There are eight DSP presets (EQ curves) and eight predefined user presets. Both the stored programs and user presets can be modified, but only the user presets can be overwritten.

Stored presets include Flat, Hi-Fi (smile), White Cone (guess what this is), Faux Finnish, Studio Cube, Boom Box, BBC dip, and 80 Hz highpass. Of course, this emulation does not include the characteristics of polar pattern, time response or distortion. User presets are Warmth, Bass Boost, Bass Cut, Treble Boost, Treble Cut, AM Radio, Narrowband, and Portable Radio. Each setting is a different EQ curve applied to the basically flat response of the speaker. In addition, the overall level can be adjusted.

Any number of speakers can be controlled by a single PC. Each monitor can be set to have a channel ID number from 1 to 16. If you set two or more monitors to the same channel, they are all controlled the same way by the software. You can address up to 16 speakers individually. Multiple speakers also can be controlled from a single speaker.

In Use

When I first saw the DSP feature I thought, "Oh no, another level of complication. Do we really need all this DSP in a monitor?" Turns out it was easy to set up and use, and I appreciated the ability to tweak the monitor's response for my control room's acoustics. For example, the flat response setting sounded too bassy because of the wall and console and wall surfaces. But by shelving down the low end 2.5 dB, I achieved just the right balance.

The software that controls the DSP is like an EQ plug-in. Using a mouse, you can drag the frequency-response curve to change the response, or adjust level, frequency and Q. Assign the speaker channels, save your presets, and you are done. The interface is very intuitive. It was fun and revealing to instantly switch between speaker emulations and hear the tonal differences.

The operation manual does a thorough job of explaining how to use the system.

Time for a listening test with the Flat preset. I placed the front of the monitors 2.5 feet from an absorbent wall behind them, and toed them in to aim at me. They were 1 meter apart and 1 meter distant. Here are my impressions of the ProLinear 820 DSP reproducing various musical instruments:

Bass: Heavy and full because of the surface reinforcement mentioned before. This can be corrected with the unit's DSP. Very deep bass. Uniform volume of bass notes.

Piano: Realistic. Clear and detailed.

Drums: Smooth, with lots of impact.

Kick: Deep and solid.

Cymbals and percussion: Crisp, sweet and smooth. Not harsh.

Orchestra: Detailed and transparent. Natural. Slightly hard in the upper mids, but not bad.

Acoustic guitar: Detailed, natural.

Voice: Natural.

Sax: Natural.

Electric guitar: Good balance of body and bite.


The sound of the Alesis ProLinear 820 DSP is something special. There is a wonderful sense of real human beings playing the music or singing. I have heard this effect before in high-end audiophile speakers. The transparency and resolution of detail is remarkable, as is the stereo imaging. It is easy to hear any graininess in digital reverb. Listening fatigue is very low as well. Overall the system sounds neutral and wide range with excellent deep bass. Plus, it can play really loud when necessary. Mixing is easy with the 820 DSP because everything sounds so clear.

I think the built-in speaker emulations and user EQ presets are highly useful. A mix may sound great on a flat system, but can it translate to a boom box or a car stereo? The ProLinear 820 DSP will let you know.