TSD 2CH Audio Level Controller/Limiter

Part of the ‘TSD’ Time Saving Device range, Atlas IED’s new TSD- ALC2 is an Automatic 2-channel Audio Level Controller / Limiter which allows audio sources on a system to be set with a predetermined maximum volume level.

The TSD-ALC2 is ideal for systems with multiple sources (such as satellite receivers, MP3/CD players, etc) which typically have wide irregularities in line level outputs.

By inserting the TSD-ALC2 in line with these audio signal sources, the listener will not be distracted by annoying high volume levels from certain audio sources or commercial breaks (which often feature significantly higher volume levels than standard programming or music).

Features include stereo RCA input / output connectors, threshold level, ramp speed selection and output gain adjustment.

Use with T4818ST Plugtop Power Supply.

Atlas IED Time Saving Device (TSD) range
The TSD- ALC2 is part of the new Atlas IED ‘Time Saving Device’ (TSD) range – designed to solve many of the most common audio system installation problems with simple, low cost and efficient solutions.

Using high quality components and real-world application design solutions, the TSD range includes compact mixers, amplifiers, pre-amps and a range of audio signal distribution & control devices.

Atlas IED’s Time Saving Devices are feature-loaded and designed with simplicity of installation and use in mind – saving time, money and hassle. Each unit is housed in a highly compact, robust metal housing.

 Understanding an Audio Level Controller
Variable audio levels between songs or TV programs and commercials can be very aggravating in a home or commercial environment. Because the audio content varies drastically, Auto Level Controllers (ALCs) require unique settings to maximize the audio auto level performance for the specific application. Most Audio Auto levelers on the market claim to seamless transition between sources or material, however no ALC can perfectly
auto-level audio. No ALC has perfect seamless audio auto leveling. In fact, many bad designs that utilize old technologies or are incorrectly used have given ALCs a bad name. The TSD-ALC2 is designed with the latest technology and optimizes adjustments and settings for each unique installation.

Determining a signal’s sample rate is important for an ALC to detect when the source material audio level is actually changing or if it is just dynamic changes within the song. A fast reaction time is necessary to quickly adjust the level but if it is set too fast, an audible pumping effect will occur when music content with a lot of drums goes to a piano, for example. Too slow of a reaction time can also be annoying during transitions between tracks or to commercial breaks. Another issue ALCs must overcome is the level of variation between input signals. If it is too large, the compensation creates an abrupt level change that is noticeable to the listener. If the level adjustment is too small, the song or commercial can be well into its content before the level adjustment occurs. Either way, the overall listening experience is disrupted.

The TSD-ALC2 solves these signal level issues without the need to of a computer and measurement tools to tailor the settings to the job. The TSD-ALC2 uses 42 audio samples per measurement, averages out the signal levels, and makes an adjustment every 20 milliseconds if required. This has been determined as the ideal sample rate to detect the audio dynamic content and make adjustments in most applications. The TSD-ALC2 also allows you to select how much the level can be adjusted, at either 1dB or 2dB increments. The TSD-ALC2 also incorporates an adjustable hard limiter so the maximum level in an audio system cannot be overdriven. The Output Level Limiter can be adjusted from 100mv to 1.5V.

The TSD-ALC2 provides a smooth transition between music or audio source selections. Auto level changes depend on how drastic the level needs to be adjusted but, in most situations, auto leveling isn’t noticeable and will greatly improve the listening experience. Secondly, the output limiter feature prevents users from turning up the gain too loud and damaging your speakers - an invaluable feature that alone makes the TSD-ALC2 worth adding to any system.

• Click to download: tsdalc2_spec.pdf

• Click to download: tsdalc2_manl.pdf