SPM Meter Systems resolve the quandary between using Peak or VU meters. These "on-line" systems use true VU meters, but are instantly switchable to a PPM mode.

The SPM-220's Peak Hold can capture and retain the highest peaks for later review, even while monitoring in VU. Push button selection of Matrix stereo metering in both Peak and VU modes allows easy detection of polarity inversions, thus protecting the mono sum. The SPM-220 is a 2 channel audio meter in a 2 RU chassis with a built-in stereo headphone amp and a Peak indicating LED on each meter.

The SPM-320 has the same features as the SPM-220, plus a third meter that may be used with SCA or SAP, or internally assigned for continuous mono monitoring.
Features

* Selectable VU or PPM metering on VU meters
* Selectable discrete stereo or matrix metering
* Peak hold capability even in VU metering mode
* True VU volume indicators per ANSI spec.
* XLR loop-through inputs (balanced 100k ohm)
* BNC scope outputs for Lissajous monitoring
* High output stereo headphone amp
* Balanced XLR outputs for aural monitoring systems (Internal patch points allow the outputs to follow the headphone amp.)