The Shure MX391/O is a low-profile omnidirectional boundary condenser for conference tables, lecterns and stage floors, the discreet install mic that uses the surface itself as part of the pickup. The furnished RK100PK inline preamp provides the RF filtering and the balanced XLR output; the cartridge is interchangeable if requirements change.
Features
Low-profile boundary condenser for tables and floors
Interchangeable cardioid / supercardioid / omni cartridges
RK100PK RFI-filtering inline preamp furnished
Active balanced, transformerless output
4m attached cable
NoteNo mute button or logic, for programmable muting and automatic-mixer logic, see the MX392/MX393 range.
Specifications
| Type | Boundary condenser microphone |
| SKU | MX391/O |
| Polar pattern | Omnidirectional |
| Frequency response | 50Hz-17kHz |
| Power | 11-52V phantom, 2.0mA |
| Cable | 4m to 4-pin mini connector |
| Included | RK100PK preamp, storage bag, Allen key |





