The device model numbers printed on Cambridge sound masking emitters allow you to quickly identify the emitter type.
The quick explanation
Emitters are denoted as either Powered (active) or Adjustable (passive) and by color. The length of cable and number of emitters per bundle are also included in the model number of emitters that were sold as part of a product bundle.
These emitters are powered (active) and come in white. They are bundled with 16-foot cables (not pictured) and come in a pack of 4 emitters. Therefore their model number is E-P-W-16-4
These emitters are Adjustable (passive) and come in Black. They are bundled with 25-foot cables (not pictured) and come in a pack of 4. Therefore their model number is E-A-B-25-4.
The long explanation
A detailed breakdown of the information encoded in an emitter model name.
E - Emitter. At present, Biamp has only one type of device under this naming scheme. Our other Cambridge and Dynasound emitters have their own naming convention.
A - Adjustable (Passive) The emitters could handle a wider dynamic range than thir in-plenum counterparts, as well as each emitter unit having its own gain adjustment dip switches near the I/O. A feature shared with the active emitters as well. These emitters were only designed to handle sound masking signals, they can be made to carry background music or masking in certain setups, but this is outside the intended usage for the emitter and could result in damage or a significantly shortened lifespan. These emitters can be quickly identified by the "shower drain" style speaker grill.
P - Powered (Active) These emitters require an inline power supply to function properly and can accommodate sound masking signal as well as Background music and paging audio. The easiest way to identify these emitters is the more traditional mesh speaker grill with a larger port hole offset from the center.
W - White
B - Black
The emitters do come in other colors but these are the most common by far.
Cable Length in feet)
The length of cabling included in the bundle is depicted by this number, normally 16' to 32'. If this code is omitted then the bundle did not have cabling included.
Number of Emitters
The last number in the sequence will always depict the number of emitters in a bundle. Normally, bundles are sold with packs of 4.
GSA - TAA Compliant (government projects) Emitters bundles with a prefix of GSA are compliant with TAA standards, meaning these emitters were either entirely made in America (or a designated-GSA compliant country) or "substantially transformed" the US (or designated GSA-compliant country). This is purely an effort to support domestic trade, these emitters are functionally identical to non-GSA emitters.