What is the difference between a BGM system and a high SPL system?

What is the difference between a BGM system and a high SPL system?
High Sound Pressure Level (SPL) systems, often referred to as foreground systems, used in stadia, concert halls and other large venues differ quite dramatically from a system normally used for background music/paging.
The human ear has a weaker sensitivity to bass and treble frequencies at lower levels, subsequently electronics manufacturers often design products with a ‘loudness curve’ frequency response i.e. products that add in bass and treble frequencies to the sound at low-levels.
These products are often used in sound reinforcement system designs for background music systems. However the ‘loudness curve’ often cause intelligibility problems for background music systems that are also used for paging or voice evacuation systems.
Adding low-frequencies to speech transmissions tends to make them sound muffled, distant and often unintelligible or to put it another way, the resulting sound transmitted often sounds bass and treble heavy. (I’m sure we have all experienced an announcement at a railway or airport that we just cannot hear or understand).
In addition lots of loudspeaker manufacturers have been driven by a culture in the last twenty years to produce as much bass output from as small a loudspeaker cabinet as possible. This has driven some manufacturers to tune loudspeakers towards a non-linear (non-flat frequency response) which means the sound from the loudspeakers does not sound neutral.
Again this can cause intelligibility problems for paging and voice evacuation systems.
For high SPL (foreground) systems in large venues, loudspeakers and electronics with a non-linear frequency response are not acceptable.
It becomes much more critical the starting point for tuning a high SPL sound reinforcement system, that typically plays out much louder and at higher SPL’s, is from a neutral, flat response. This allows sound engineers to adjust the tuning of a high SPL system to cater for acoustic characteristics of a building, the varying size of the audience and even atmospheric conditions in an outside area or venue.
It is therefore quite critical that the right components are chosen in the inital design of a sound reinforcement system depending on whether it is for use in a background music, paging or high SPL application.
Sound Directions are experts in designing sound systems for background music, paging, voice evacuation and high SPL applications.

Where are these systems used?
Public Address, Voice Alarm and Background Music Systems are used in hospitality, leisure, retail, visitor attractions, public buildings, travel and sporting venues.