Two Channel Mixer

The AtlasIED TSD-RL21 is a 2-input by 1-output mic/line mixer intended for paging, public address, and BGM applications. Its compact enclosure measures 1.5 inches high, 4 inches wide, and 2.5 inches deep, providing the specified mixing format in a unit weighing 6 ounces. The published audio specifications cover mic and line levels, balanced and unbalanced impedances, output characteristics, noise performance, and 24VDC power requirements.

Ideal Use Cases

The TSD-RL21 is suited to audio systems that require paging, public address, BGM, or a combination of these functions. Its two-input, one-output configuration addresses installations where two mic or line sources need to feed a single output path without moving to a larger mixer format.

This model is particularly relevant when the available equipment space is limited. At 4 inches wide and 2.5 inches deep, the mixer can be considered for compact system layouts while retaining published specifications for both balanced and unbalanced signal connections.

Why Choose This Model

The TSD-RL21 combines its defined 2-by-1 signal format with a frequency response of 20Hz to 20kHz within ±1dB. The line-to-line signal-to-noise ratio is specified at 85dBV, while the mic-to-line signal-to-noise ratio is 70dBV. These figures provide concrete reference points when evaluating the unit for a paging, public address, or BGM signal chain.

The electrical specifications also distinguish between mic and line operation. The mic input is rated for 46dB of gain with a 10mV (-40dBV) balanced input level. A separate input level is listed as 316mV (-10dBV), while the published line input specification is 1V (0dBV) balanced with 2V (+6dBV) balanced output.

Installation and Integration

The enclosure measures 1.5 inches (3.81cm) high, 4 inches (10.16cm) wide, and 2.5 inches (6.35cm) deep. Its listed weight is 6 ounces, or 0.165kg. These measurements allow the required space and equipment loading to be established before installation.

Power is supplied at 24VDC, with a stated current requirement of 60mA. The voltage compatibility is also specified as 24V. Installers can use these values when planning the power arrangement for the mixer.

For signal integration, the balanced input impedance is specified as 1.2kΩ balanced and 600Ω unbalanced. A separate unbalanced input impedance is listed at 10kΩ. On the output side, the balanced line output impedance is 300Ω balanced or 150Ω unbalanced. These published values make it possible to compare the mixer with the input and output requirements of connected equipment.

Performance Highlights

The stated 20Hz to 20kHz frequency response covers the mixer’s published operating range with a tolerance of ±1dB. Total harmonic distortion is listed as .06% & 1kHz. The line-to-line signal-to-noise specification of 85dBV and mic-to-line specification of 70dBV provide separate performance references for the two signal paths.

The balanced mic input is specified at 10mV (-40dBV) with 46dB gain. The general input level is 316mV (-10dBV), and the listed line input level is 1V (0dBV) balanced. Together with the documented input and output impedances, these details support careful level and impedance planning during system design.

What Makes It Different

The TSD-RL21 focuses specifically on two-input, one-output mic/line mixing for paging, public address, and BGM. Rather than presenting a broad collection of unrelated functions, its published data centers on the audio levels, gain, impedances, frequency response, noise ratios, physical size, and power requirements needed to assess this particular role.

Its combination of a 4-by-2.5-inch footprint, 6-ounce weight, balanced and unbalanced impedance specifications, and 24VDC operation gives system planners a clearly documented set of integration parameters. The mixer is also covered by a warranty lasting 36 months from the date of purchase.

Final Assessment

The AtlasIED TSD-RL21 is a focused option for installations requiring a 2-input by 1-output mic/line mixer for paging, public address, or BGM. Its published 20Hz to 20kHz response, separate mic-to-line and line-to-line noise specifications, 46dB mic gain, and balanced and unbalanced impedance data provide a detailed basis for system matching.

With a compact enclosure, 24VDC power requirement of 60mA, and a 36-month warranty from the date of purchase, the TSD-RL21 presents a defined set of electrical, physical, and application-specific characteristics for compatible audio installations.