The dbx DriveRack PA2 is one of many Loudspeaker Management Systems currently available to the Pro Audio community, but do these systems also have a place among audiophiles? Many purists will complain that any digital device adulterates the original analog signal, and that EQ is never a good thing. We disagree with this type of thinking.

Your collection of recordings, whether they be purely analog (vinyl and tape), digital, or a mix of both, have already been subjected to equalization, compression, and many other processes at the studio. Further, most modern studios employ room correction to their monitoring systems to improve their accuracy. If you want to hear the recording as it was intended you’ll need to use similar technologies. In the past these systems were well beyond the budget of most audiophiles, but today they can be purchased for around $300-$400.

What is a Loudspeaker Management System (LMS)?

LMSs combine many pieces of equipment required to setup a live or studio environment into one.

• Compression
• Feedback Suppression
• Equalization
• Subharmonic Synthesis
• Crossovers (2 way, 3 way, etc.)
• Limiting
• Driver Delay

Audessy and Dirac are types of LSM available in consumer products. They are included in many AVS receivers and amplifiers. Products like the DBX DriveRack PA2 can be added to any system, even vintage gear.

Why do I need one?

For those of you who have a 2 channel (stereo) system, and use the passive crossover networks built-in to your loudspeakers, you may be wondering how an LMS would benefit you. Before we answer that question, let’s define ‘Stereophonic Sound’.

Stereophonic sound or, more commonly, stereo, is a method of sound reproduction that creates an illusion of multi-directional audible perspective. – Wikipedia

In other words: stereo is an attempt to trick your ears into believing a sound field is real. Your ears, however, are not easily fooled. You’ve spent your entire life training your ears to know the difference between sounds coming from in front of you and those arriving from behind. Your ears are also sensitive to timbre and a host of other sound quality factors. The goal of every audiophile is (should be) to have a sound reproduction system that convinces both the ear and brain what is being heard is real.

To accomplish this requires more than good frequency response and life-like dynamics. Sounds must arrive with millisecond accuracy to the ear, be of the anticipated timbre, etc., and be free of distortions. Any deviation from this shatters the illusion of reality.

An LMS allows you to further refine your system thereby making it even more convincing to your ears and brain. It can also grow with you. As your knowledge and understanding of sound reproduction expands, it can also act as a very sophisticated active crossover for bi and tri-amping further reducing distortion and timing issues.

The future improvement of sound reproduction lies with DACs, LMSs, and acoustic lens technology. Some modern Pro systems already utilize all three, and the results are amazing.

In a future article we’ll be using a dbx DriveRack PA2 LMS  to improve a vintage system with a pair of Altec Lansing Model 14s.  This will provide a real-world example of how all audiophiles can take advantage of an LMS.