Foreground & Background
Broadly speaking, there are two primary commercial audio market application sectors. They are often very different markets, separating technologies and product solutions in targeting either the 'foreground' or 'background' audio markets.
Whilst not a strict rule, we view most background audio applications as being based on a '100 volt' suite of technologies and products (often termed as high impedance or constant voltage systems). Foreground audio applications (low impedance systems) employ a completely different design, running with much lower output voltages and lower speaker impedances.
Foreground audio systems (often termed low impedance systems) are most strongly associated with live event, stage and performance based sound reinforcement (singers and musicians).
In a general commercial setting, we find there is limited need for foreground audio applications, mainly due to complicated design and limited speaker deployment flexibility.
Stage and Performance
Stage and music performance events are synonymous with foreground audio. Foreground audio is generally used where higher audio / volume levels are required and that is intended for lengthy periods of 'active' listening.
Foreground audio and 'music quality'
Unlike background audio systems, foreground audio systems don't employ line transformers within their speakers. With particular attention to amplifier / speaker impedance matching, foreground audio systems can be designed for excellent audio frequency response.
The transformers used in the 100 volt background audio systems are not used in foreground audio systems, which eliminates some of the quality effecting issues sometimes observed with 100 volt speakers (frequency response, insertion loss, capacitance).
In a general commercial setting, most background audio systems will be used to provide low level background music and / or public address 'tannoy' paging to make voice announcements. There is a huge range of different commercial business application of background audio, some examples are as follows:
Public Address (PA) and 'Tannoy' Applications
Commercially seen everywhere. Factories and industrial units, warehousing, public and government places, offices, schools, retail, sports.... the list is endless.
Background Music (BGM) Applications
Retail, shopping centres, restaurants, doctors surgeries.... BGM/Radio can provide ambience and atmosphere. Designed and used correctly, numerous studies have shown that BGM can also have a positive economic effect, particularly within the retail and hospitality industries.
Why use a 100 volt system?
In the UK, most commercial background audio systems are based on amplifier and speaker designs providing for both a high voltage and high impedance. The high voltage output of the amplifier (up to 100 volts) affords smaller cable sizes over longer range audio transmission distances which allows us to design PA / 'Tannoy' and BGM applications over 100's of meters (sometimes km's). In this design, the speakers have a transformer built into them, this steps down the voltage for power delivery to the speaker (many speakers have a number of 'tappings' to the transformers which provides for some basic power and volume levels control).
As well as long range speaker cabling distances, the 100 volt audio system also affords greater speaker deployment flexibility.