Voice-Over / Paging Module-Manual

Ideal Use Cases

The RDL ST-VP1 is designed for voice-over and paging systems in which a voice signal must take priority over music. It supports applications requiring either a controlled reduction in music level or a direct cut between two input sources. This makes it well suited to noiseless paging and voice-over work where repeatable fade levels matter. The voice input is adapted for paging or voice-over use, while selectable fade-under and hard-cut modes allow the module to match the required transition. Soft audio switching helps maintain clean changes between program material and voice content.

Why Choose This Model

The ST-VP1 combines adjustable audio control with automatic signal handling. Music fade depth can be set from 0 dB to −25 dB or switched off, giving the operator control over how far the music is reduced during a voice event. Music recovery delay is adjustable from 2 to 4 seconds, while the listed voice trigger level is 24 dB below operating level. An integrated AGC/compressor provides an 18 dB range and 6 dB of compression at normal input level. With a 25 ms attack time and 2.5-second release time, the processing is specified to respond quickly to voice activity while controlling the return to the music source.

Installation and Integration

The module provides two balanced line-level inputs that may also be used unbalanced. Input impedance is 20 kΩ, and the specified input signal range is 20 dBu to +18 dBu. The output is balanced at a nominal +4 dBu. Gain is adjustable through a multiturn potentiometer, supporting precise level setup. Two indicators assist with alignment: one LED indicates the proper music level, and a second LED indicates the proper voice level. The ST-VP1 requires a ground-referenced 24 Vdc supply at 35 mA. Recommended supplies, which are not included, are the PS-24AS for the USA and PS-24AX for international use. Automatic operation can also be achieved when the module is used with RDL ST-ACR products.

Performance Highlights

The ST-VP1 covers a frequency range of 20 Hz to 20 kHz with a stated response of ±1 dB. THD+N is specified at less than 0.01% across 20 Hz to 20 kHz when no compression is applied, while the listed noise performance is less than −70 dB. These specifications support high-quality voice-over mixing and paging throughout the audible frequency range. Selectable fade-under or hard-cut operation provides two distinct ways to prioritize voice content. Adjustable fade depth and rate, combined with soft audio switching, allow the transition to be configured for the program rather than relying on a single fixed response.

What Makes It Different

The defining feature of the ST-VP1 is its combination of controlled fade behavior and voice-triggered processing. Some applications need music to remain audible at a reduced level beneath the voice, while others require the music source to be cut. This module provides both choices in one design. Its adjustable fade depth, music recovery delay, AGC/compressor, and separate level indicators provide direct control over the interaction between music and voice. The ability to work with balanced or unbalanced input signals adds connection flexibility, and integration with RDL ST-ACR products provides a path to automatic operation.

Final Assessment

The RDL ST-VP1 is a focused solution for two-source voice-over and paging applications that require predictable audio transitions. It pairs a nominal +4 dBu balanced output with adjustable gain, selectable fade-under or hard-cut operation, and configurable music recovery. Its 20 Hz to 20 kHz frequency response, low stated distortion, voice-trigger threshold, and integrated compression provide a defined technical foundation for paging and voice-over mixing. Choose this model when controlled music reduction, noiseless paging, or consistent voice-over fade levels are central requirements.