When evaluating pricing, qualifications and approach for the design and installation of a sound masking system, there are several key points to compare.  You should ask follow up questions from each provider to ensure that you know what you are getting and that you are getting what you want and need:

Speaker type:  Make sure that your proposals define the type of speakers that will be used.  You will find two basic types: plenum based speakers (indirect field) or down ward facing speakers (direct field).  It is our opinion that with a few exceptions, direct field speakers do not provide the uniformity required for a high quality sound masking system (see earlier entry below).

Speaker Count:  Sufficient speakers need to be provided to create uniform sound coverage through out the space.  Ask for the number of speakers, speaker spacing and confirm the coverage area from each respondent.   This can make a big difference in price and performance.

System Type:  There are several basic types of sound masking systems.  Make sure you know which type you are getting: 

Centrally Controlled systems provide an equipment rack in a single place within a building or space.  The system requires power at this location only and all wiring to the speakers is low voltage. 

Distributed Systems utilize powered speakers each containing a small sound masking generator and amplifier within the speaker housing.  These systems usually require access through the ceiling to make adjustments or changes.  They also require power sources above the ceiling.  When comparing pricing, make sure that the price includes electrical work to install the necessary power supplies.

Networked Systems provide sound masking through a system that is similar to a computer network.  They use CAT 5 or CAT 3 cable instead of low voltage speaker wire.  Signals are sent from a central computer to network nodes located through out the plenum.  These nodes will require power.  Check pricing on electrical work.  The nodes then feed signals to speakers.  See write up below on comparing networked systems to central systems.

Installation:  It is critical to evaluate who will be installing the sound masking system.  Are you dealing with a turn-key provider that will be responsible for the entire process of speaker and wire installation as well as the critical testing and tuning?  Or are you dealing with a sales representative that will outsource the installation to a third party.

Ask who will be tuning the system.  The proper tuning of a sound masking system will determine its effectiveness.  Ask them to describe their tuning process and what tools they will use.  You may get a few blank stares from some of the providers.  But you will be able to determine the vendors that understand the critical details of the system commissioning.

Choosing a sound masking system:

When investigating the purchase of a sound masking system, you will be introduced to several different concepts. 

One of the most important characteristics of a quality sound masking system is uniformity.  As people circulate through the workplace, the sound masking should be uniform.  Differences in volume or spectrum will draw attention.  Sound masking should be unobtrusive and blend into the background.

There are several manufacturers in the market today that are using systems with a network backbone.  They are designed like a computer network.  They use a central computer to send information to network nodes that then distribute the signal to sound masking and paging speakers.

The computer allows small groups of speakers to be changed remotely to allow differing volume levels and spectrum adjustments.  The manufacturers of these systems use terms such as “separate and independent configuration” and “on-demand control”.

After initial commissioning, the Facility Manager will have the controls and as changes are made, the system will become less uniform.  With each change, the system will drift away from its intended purpose of masking conversational distractions.

We strongly feel that networked systems provide Complexity without Benefit.

The systems also require electrical connections located through out the treated area to power the network equipment and the speakers.

Centrally controlled low voltage systems require a single electrical connection at an equipment rack.  All wiring from the rack to the speakers is conducted through low voltage plenum rated cable.

Centrally controlled systems provide the ability to deliver highly zoned sound masking and paging with a stable and reliable platform.  Once commissioned, they run trouble free for years.

By all means, compare systems and compare prices.  Then take a look at the organization and ask several key questions:

• Who will install the system?
• Who will commission and tune the system?
• Who will be responsible for service calls?

Many times, large manufacturer’s representatives subcontract installation and service to data cabling firms.  Look for suppliers with in-house personnel and expertise in sound masking and acoustics.