Dual Channel Microphone Compressor

The RDL HR-MCP2 is a two-channel microphone compressor designed to produce consistent microphone levels while controlling overloads that can cause distortion and clipping. Its two independent channels can operate as a stereo pair or as separate mono signal paths. In addition to feeding microphone inputs, its line-level outputs allow the unit to function as a dual microphone preamplifier.

Ideal Use Cases

The HR-MCP2 is suited to systems that require dependable control of changing microphone levels before signals reach a mixer or amplifier. It installs between microphones and the microphone inputs of downstream equipment, making it useful when varying source levels could otherwise produce clipping or inconsistent output. Independent channel controls support two unrelated mono sources as well as stereo operation. Selectable 48 V phantom power accommodates microphones requiring phantom power, while a switchable 15 dB pad on each input provides added input-level capacity.

Why Choose This Model

Each channel combines input conditioning, adjustable gain, compression monitoring, and overload indication in a compact unit. Front-panel gain controls provide continuous adjustment from 20 to 60 dB for the line-level outputs. A red CLIP indicator flashes when a signal peak is within 1 dB of clipping, giving the operator an immediate warning before the signal reaches the clipping point. Seven yellow gain-reduction LEDs per channel display instantaneous compression in 3 dB increments from 3 through 21 dB.

The balanced inputs and outputs are available on rear-panel three-pin XLR connectors and detachable terminal blocks. Each output supports either a balanced or unbalanced connection, allowing the compressor to integrate with different downstream input configurations.

Installation and Integration

The HR-MCP2 may be operated free-standing with the included feet or installed in a rack using an optional rack adapter such as the HR-RA2. Its enclosure measures 1.7 inches high, 8.6 inches long, and 4.59 inches deep, equivalent to 4.3 by 20.6 by 11.66 cm.

Both input channels have balanced impedance greater than 1.5 kΩ. With the pad disabled, maximum input level is greater than +5 dBu; with the pad enabled, maximum input level is +22 dBu. The nominal 15 dB pad is applied before the input stage. A front-panel FILTER switch enables or disables a 6 dB-per-octave low-cut filter with a -3 dB cutoff at 80 Hz.

The unit requires ground-referenced 24 Vdc power at 200 mA, increasing to 230 mA with phantom power active. Recommended power supplies are the PS-24AS for the USA and PS-24AX for international use.

Performance Highlights

In flat mode, frequency response extends from 10 Hz to 25 kHz within ±0.5 dB. Enabling the low-cut filter produces a -3 dB response at 80 Hz, helping tailor the signal before it reaches the downstream mixer or amplifier. Common-mode rejection is greater than 70 dB from 50 Hz to 5 kHz, and crosstalk is specified as below the noise floor.

Residual noise is less than -85 dB below rated output from 20 Hz to 20 kHz at 40 dB gain without compression, using a 150 Ω source. At 60 dB gain under the same conditions, residual noise is less than -70 dB. Total harmonic distortion is specified as below the noise floor at 3 dB of compression.

Nominal microphone output is -45 dBu into 600 ohms. The balanced line output is nominally +4 dBu with a dynamic audio source and +1 dBu with a sine wave producing 3 dB of compression. Output impedance is 150 Ω balanced.

What Makes It Different

The HR-MCP2 combines two independent compression channels with both microphone-level and line-level output operation. This enables it to serve either as an inline microphone level controller or as a dual microphone preamplifier. Per-channel gain adjustment, input pads, low-cut filtering, clip warnings, and seven-stage gain-reduction displays give the operator direct control and visible feedback without requiring shared settings between channels.

Connector flexibility is another practical distinction: two XLR inputs, two detachable-terminal-block inputs, two XLR outputs, and two detachable-terminal-block outputs support permanent installations as well as conventional XLR-based systems.

Final Assessment

The RDL HR-MCP2 provides two independently controlled microphone compression paths in a compact free-standing or rack-mountable format. Its 20 to 60 dB gain adjustment, selectable 15 dB pads, 48 V phantom power, 80 Hz low-cut filters, balanced connections, and detailed gain-reduction metering make it a focused solution for maintaining consistent microphone levels while monitoring overload conditions.