The History of Radio Design Labs

Radio Design Labs, Inc.®, abbreviated RDL®, is a manufacturer of electronic audio, video and control products headquartered in Prescott, Arizona, USA. Its products are distributed worldwide for use in commercial and residential audio and video installations and in broadcast and recording facilities. The company is known as the pioneer of application-specific electronic modules. The company produces modules in trademarked product series including AV-PAK™, FLAT-PAK™, FORMAT-A™, RACK-UP®, STICK-ON®, SYSFLEX™ and TX™.


Radio Design Labs was established in January 1986 in Carpinteria, California, United States. The company name was chosen for its founders’ extensive engineering and sales experience in the broadcasting industry. The purpose of the business was to design and manufacture electronic modules and equipment for the broadcast, commercial sound, video, audio-visual and recording markets. The company set out to distinguish itself by three characteristics. First, all products would be designed and manufactured to exact standards of professional performance and longevity previously reserved for broadcast and recording equipment. Second, the core product groups would be comprised of single-function modules enabling many features to be added to audio and video system designs. Third, the company would offer a broad base of technical and system design support to its customers led by an engineering staff with field experience. These principles have guided the company throughout its history.

In September 1993, the company relocated its manufacturing division to Prescott, Arizona, United States. The sales offices remained in Carpinteria, California until December 2004 when all U.S. operations were consolidated to the factory campus in Arizona.

RDL-Europe, B.V. was established as a subsidiary company in Amsterdam, The Netherlands in 1998. RDL-Europe serves as the RDL master distributor, providing inventory, sales, and service for Europe (EEC) and surrounding regions.

In 2022, RDL was acquired by private equity group VOPNE Capital, allowing for additional investments in people, machinery, and equipment. As a result of this additional support, RDL celebrated its strongest year in history in 2023 by producing and shipping a record number of products.

Application-specific Modules

Audio and video systems in the years leading up to the founding of RDL were characterized by technical designs based on features available in commercial amplifiers and mixers. Examples include signal mixing, equalization, source selection and signal distribution. Available features often did not meet the optimal system design requirements, so system design flexibility was constrained by the functional limitations of the equipment used. RDL set about to change the way systems were designed through the use of single-function modules, also known as application-specific modules. Each module performs essentially a single function, such as mixing, equalization, source selection, signal routing, signal distribution, signal detection or remote control. The isolation of functions into single, low-cost high-reliability modules offered system designers complete flexibility to interconnect multiple modules in virtually unlimited combinations to create systems with previously unattainable features. This method of system design and installation was widely adopted within a few years of its introduction. RDL application-specific modules are used by nearly all system integrators in the United States and by progressive designers and installers worldwide.

Audio products comprise the greatest diversity of function, including Power Amplifiers, Transformers, Processing, Paging, Microphone products, Mixing, Line Amplifiers, Test Equipment, Interface products, Pre-amplifiers, EMC (electromagnetic compatibility) products, Program Monitoring, Distribution, Signal Generators, Meters, Speakers, Crossovers, Filters, Attenuators, Phono pre-amplifiers, VCAs (voltage controlled amplifiers) and products to provide local and/or remote Switching.

Certain functions offered in the Audio products group are applicable to other signal types. RDL Video products include Distribution, Attenuators, Line Amplifiers, Detectors, and a variety of related video switching modules.

STICK-ON Modules

The first application-specific module, called STP-1, was sold in 1987. Within weeks, several additional modules were added to the STICK-ON series. The line quickly grew to nearly 50 different products. STICK-ON modules are compact monolithic plastic modules interconnected through high quality terminal blocks. An installation may consist of a single module, or multiple modules may be mounted in various RDL racking adapters. The STICK-ON series quickly became popular because the modules are compact and lightweight enough to be mounted right where they are needed. Dual Lock reclosable mounting fasteners are included with each product.

Other Product Series

Shortly after the introduction of the STICK-ON series, RDL introduced the first products in the RACK-UP series. These modules provide many of the STICK-ON series features and functions in a larger mechanical format with connectors. RACK-UP modules are primarily intended for rack-mounted installation. FLAT-PAK modules specialize in features common to back-board mounted installations. Other series including TX and AV-PAK modules meet the needs of various installed and end-user applications. Many RDL modules may be remote controlled. The company produces remote control and connection panels that are compatible with standard North American and European electrical boxes.

Broadcast Products

The various series of RDL modular products provide the high reliability, longevity and flexibility suited to commercial audio/video, home audio/video, professional studio and broadcast users. RDL is also known for broadcast-specific products. The best known is the series of Amplitude Component Monitors. The ACM-1, ACM-2 and ACM-3 represent three generations of monitors that are used by FM radio stations to maximize their effective coverage areas, often extending the useful service areas by several miles. The first of these instruments, the ACM-1, was introduced in 1988.

Signal Distribution and Engineered Systems

Building on its reputation for quality modular system design components, RDL developed FORMAT-A, a pre-engineered audio system and modular audio and video signal distribution using Cat-5 or better twisted-pair cabling.

RCX™ Room Combining Systems are widely used to automatically control audio mixing and routing for hotel meeting rooms. SOURCEFLEX™ system products are used in a variety of facilities to distribute and select multiple audio channels.


RDL manufacturing is characterized by broad vertical integration. Fabrication and assembly processes are maintained in-house, including plastics molding and encapsulation, metal fabrication, forming and powder-coating, product printing, panel laminate manufacturing and precision laser cutting. Assembly, including component placement, soldering and product testing is automated using computerized machine control. All RDL products, except power supplies, are made in the United States, are CE and RoHS compliant and carry a three-year warranty. Manufacturing and packaging employ environmentally safe, recyclable materials and processes. RDL accepts end-of-life returns of all RDL modules for full recycling.

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