Last year's NAB Show saw the debut of the DaySequerra M4DDM Diversity Delay Monitor. The idea was an analog-digital diversity monitor that automatically synchronized analog and main HD Radio channel broadcasts, solving the problem of drifting over time.
New year and a new product, the M2DDM. This is larger at 2 RU but contains an improved feature set, according to the company. Like its sibling, it uses a proprietary DSP-based algorithm called Time-Lock to measure the HD Radio analog and digital program diversity differential with accuracy to one audio sample. Using a selective off-air tuner, the M2DDM measures the MPS analog and HD1 digital audio diversity; calculates the number of audio samples that must be added or subtracted to synch the two audio streams; determines the level offset required and generates a continuous stream of correction vectors to keep the analog and digital audio time- and level-aligned.
The correction vectors can be processed internally by the M2DDM to delay the digital program audio or sent via Ethernet to an Embedded Exporter or audio processor to provide the necessary adjustments to the analog audio delay.