AKG WM81 Beige Wire-Mesh Caps for Cardioid MicroLite Mics 5-Pack

AKG WM81 Beige Wire-Mesh Caps: Structural Protection for Cardioid MicroLite Capsules

The AKG WM81 beige 5-pack supplies five wire-mesh protection caps for the cardioid MicroLite microphones, described by AKG as protecting the membrane from wind and pop noise as well as dirt such as make-up or dust. Cardioid MicroLite microphones can be used with or without the cap, which makes it an optional but strongly advisable part on any microphone that will be handled by anyone other than a sound engineer. Beige is the finish for concealed mounting on fair hair and light skin, the position most theatre and broadcast rigs actually use. Five to a pack reflects how these are bought, which is by the rig rather than by the microphone.

What Rigid Mesh Does That Foam Cannot

A wire-mesh cap and a foam windscreen are often treated as alternatives, and they are not. Mesh is a structural component: it is stiff enough to stand off the diaphragm and hold a physical gap, so a fingernail, a costume hook, a headset band or a microphone dropped on a dressing-room floor meets metal instead of meeting the capsule. Foam has no such stiffness and simply compresses, which is why it excels at slowing airflow and does almost nothing against impact. Screening dirt works on the same principle, because a fine mesh at a fixed distance from the membrane intercepts powder and airborne debris while presenting so little acoustic obstruction that the microphone's published response is preserved. Any production where performers dress themselves, run, or handle their own microphones needs the mesh in place before it needs anything else.

Cardioid Fitment and the Rear Acoustic Path

Pattern family is not optional information on this part. Cardioid MicroLite models carry the digit pair 81 and their capsule housings are built around a rear acoustic path, the vent that lets sound from behind cancel sound from the front and creates the directional pattern in the first place; the housing dimensions and the cap that fits them are set by that geometry. Omnidirectional models carry 82, use a smaller pressure-operated capsule and take the WM82 cap, and fitting an 82 cap to an 81 microphone or the reverse either will not seat or will interfere with the acoustic path that defines the pattern. A cap that obstructs the rear path turns a cardioid into something with an unpredictable response, which is far worse than having no cap at all. Order by the digit pair first and by colour second.

The Wig Room, the Hairline and a Beige Rig

Theatre sound departments mount body microphones where the audience will not see them, and in practice that means the forehead hairline, the temple, a parting under a wig cap, or occasionally the front of an ear-hook frame. Every one of those positions sits against skin or hair, so a beige cap, a beige windscreen and beige tape read as one continuous nothing from the auditorium while a black cap reads as a dot. Wig supervisors typically build a complete beige rig per performer and keep it with that performer's track, which is why caps are ordered by the pack and matched to the rest of the concealment kit. When conditions turn windy or a scene puts a performer in front of a fan, the W81 foam windscreen goes on over this cap rather than replacing it.