The new SM7dB has three operating modes: Bypass and either +18dB or +28dB of additional gain. These are set with slide switches on the back of the mic. +48-volt phantom power is required for the pre-amp, but you can leave it always on and freely switch back and forth between the original SM7B's sound in Bypass mode and then the SM7dB with the additional gain if you need it. Usually, the +18dB boost of gain is more than enough.

Other updates include: four easy-to-adjust slide switches replace the recessed switches used in the SM7B. These switches change between the three modes, the high-pass filter and the presence boost on/off switch.

These filters are available and work the same in either Bypass or Active modes just like the original SM7B microphone. I liked that the new slide switches are easier to use and are readily available.

The SM7B's popularity stems from its wide range of uses from radio station DJs to recording loud singers, or guitar amps and even close to drum kits. Its versatility has expanded with the increased gain required to record very quiet sources. The Shure SM7dB Dynamic Vocal Microphone sells for: $499 MSRP and Shure will continue to offer the SM7B at $399 MSRP.

More information at: Shure Microphones