RTW's History Since 1965


At NAB 2022 in Las Vegas, RTW for the first time showed TouchControl 5, the Dante® based immersive monitor controller and meter.
Based on the tried and tested monitoring controller engine, which many are already familiar with from RTW's older surround monitor controllers, a modern device has been developed for controlling and monitoring up to 32 AoIP channels. With the web-based interface, channel configurations from stereo to 22.2 including 5.1 and 7.1 surround as well as 7.1.4 and 9.1.6 immersive with 4 input and 4 output sets can be created and monitored on a 5" display. Special features include comprehensive speaker level calibration and live SPL measurement with the built-in measurement microphone as well as bass management for each individual speaker and talkback.
The RTW standard precision metering tools are also integrated.

to TouchControl 5 product page >

As a next step, the Dante- and Ravenna-compatible TouchMonitors get functionalities allowing measurements according to the latest standard within Audio and Video over IP: SMPTE ST 2110.

SMPTE ST 2110 is a major contributing factor in the development toward a single IP-based mechanism for the professional broadcaster. Like SDI, it carries audio, as well as video and metadata, but unlike SDI, it is based on IP technology, which makes it a true network. With the ST 2110 expansion of the TouchMonitors, broadcasters and content providers that are adopting the new IP-based infrastructure will get truly professional audio meters.

to TM9 product page >
to TM7 product page >

More and more broadcasters and post-production studios are switching to a Dante™ network infrastructure. So it was obvious to implement this standard in the TouchMonitor TM7 and TM9 series devices and to enable the measurement of up to 32 audio channels of a Dante™-AoIP network with 96 kHz sample rate. In addition, redundant network connections are supported to ensure that all audio signals are always reliably monitored.

With the new Immersive Sound Analyzer, monitoring of spatial formats similar to Dolby Atmos® is also possible.

Networked audio solutions also play an increasingly important role in broadcasting. Therefore, during the course of the year, TouchMonitor devices were expanded to allow integration into Ravenna/AES67 AoIP networks.

to info page Let's Talk Dante >
to info page TM Goes Immersive>
to info page Let's Talk Ravenna and AES67 >

Many viewers and listeners have difficulty understanding verbal material in shows and films. Specific complaints include that an actor does not articulate clearly enough or that there is too much background noise.
As part of a research project in cooperation with the Fraunhofer Institute for Digital Media Technology (IDMT) in Oldenburg and funded by the German Federal Ministry of Economics, SMEs and Energy (BMWi), RTW is starting to develop a technology that enables the audio analysis of film and television dialogues with regard to speech intelligibility in real time.

RTW takes over the initial distribution of the PD-Dante portable diagnostic system from Nixer Ltd., United Kingdom, for two years. The PD-Dante can be used to monitor and listen to individual Dante® audio streams in the (ether) network, or audio streams summed locally in the device.

At NAB in Las Vegas, RTW presented the prototype of audio processing hardware APRO-CLC01. Firstly developed as an OEM product, the audio processor also uses the loudness correction algorithm developed and patented by Institut für Rundfunktechnik (IRT) like the CLC - Continuous Loudness Control software, and provides dynamic loudness processing in live applications in real-time.

For the first time in the company's history, RTW presented an audio processing tool at IBC in Amsterdam: the CLC - Continuous Loudness Control. As the latest product of the Masterclass PlugIns series, the DAW plug-in and stand-alone application allows dynamic loudness processing in real-time with minimal obstacles in highest quality. The amazing look-ahead low latency algorithm developed and patented by Institut für Rundfunktechnik (IRT) being used in the CLC allows loudness correction of audio signals to a definable target with or without changing the original Loudness Range and protects to an adjustable True Peak value according to all common standards.

to CLC - Continuous Loudness Control product page >

In this year, RTW also launched TM3-Primus, a highly compact and innovative, easy-to-use product, giving music, voice, and multimedia producers in professional as well as non-commercial environments everything they need. Beside the use as a standalone desktop unit including analog and digital audio interfaces, TM3-Primus also provides an innovative USB hybrid mode. Metering will then be performed right from the DAW via RTW USB Connect plug-in and the TM3-Primus will process and visualize the information without the need for additional wiring or extensive signal routing. The device is the first USB meter handling audio signals via USB connecting directly from a computer.

to TM3-Primus product page >
to RTW USB Connect product page >

Depending on the experiences on programming the applications and user interfaces for the TouchMonitor series, RTW's developers had the idea to transfer the analyzer tools to a pure software that requires no additional hardware, and make them available to musicians, radio producers, and audio/video engineers who are mainly working with a DAW on Mac OS X® or Windows®.
The RTW Loudness Tools software was launched as the first plug-in of the new range of software products called RTW Masterclass PlugIns. RTW Loudness Tools feature metering and loudness display for mono, stereo, multichannel, and surround applications (8 channels max.) and, with their precisely working and easy-to-read instruments as a means for quality control, ensure compliance with custom specifications.
A little bit later, the RTW Mastering Tools software was launched as another product of the RTW Masterclass PlugIns. Beside the metering and loudness tools, this software additionally includes extensive analysis and display functions for mastering.
In the current version, the tools both can also be used as stand-alone applications.

to Loudness Tools product page >
to Mastering Tools product page >

New technologies placed in the latest products and the increase of numbers of spare parts being no longer available for the devices in the field caused restructuring of the whole development and production processes. Therewith also the demands to the company's premises changed. RTW made a find at Triotop in Köln-Vogelsang (a district of Cologne) and moved to the present location.

Some months before the EBU R128 recommendation for Loudness metering was mandatory implemented end of August 2012, RTW launched a compact, easy-to-use professional Loudness, True Peak and PPM metering device at an affordable price: TouchMonitor TM3. Its easy readable loudness-compliant level control also allows nontechnical users to handle their productions and programs according to the new loudness regulations from the beginning.
Characteristic of TM3 is the display unit with 4.3" touch screen for vertical or horizontal use and the separate interface box providing the audio interfaces. The flexible user interface allows for quick and simple preset selection. Presets can be administrated, configured in detail, and uploaded to TM3 using the Devicer DC1 software for Mac OS X® or Windows®.

to TM3 product page >
to TM3-3G product page >

Simultaneously to the launch of TouchMonitor TM7 and TM9, RTW's Corparate Design and Corporate Identity was updated to underline the advanced product design and to represent the high quality level. The RTW logo and graphical elements like the peak bars were enhanced, and visual language as well as the used font were put to a next higher level. This is also represented in the relaunch of RTW's web site, which got more focus as a information and communication platform. But also the design of the new devices and their intuitive user interfaces follows the updated Corporate Design guidelines.

The introduction of HD and surround sound, as well as loudness control issues have triggered an increasing demand for quality control and monitoring of audio signals. Fast perception and accurate assessment of audio levels using visual representation methods are indispensable elements of daily work. Sub-optimal monitoring conditions, stress and aural fatigue are just a few of a large number of reasons why relying just on one's ears is not enough.

RTW's answer to these growing requirements was the development of the TouchMonitor series TM7 and TM9, entering a new level of professional audio metering in terms of precision, performance, efficiency and flexibility.
Equipped with high-grade 7" or 9" touch sensitive screens and the scalable, modular software (licences) for flexible configuration, the easy-to-use graphical user interface used in the TouchMonitor range is controlled simply by using a finger. Instruments can be scaled, randomly positioned and combined for optimized use of available screen space. Multiple instruments of the same type, assigned to different input channels and configurations, can be displayed simultaneously and configured independently.

to TM9 product page >
to TM7 product page >

Abrupt volume level changes between different program types and channels became more and more an annoyance for listeners and audience. To get this problem under control, a reliable and standardized method for evaluating program loudness seemed to be essential in radio and TV production and broadcast. Corresponding recommendations should provide binding standards for comparing loudness measurements and enabling a global exchange of programs on the basis of unified evaluation criteria.

In Europe, the project group PLoud was founded at EBU. PLoud made a major contribution in establishing a common, vendor-independent and relatively simple way to measure loudness, creating appropriate standards, and publishing them as EBU R128 Loudness Recommendation. Simultaneously, detailed practical guidelines were created to help audio professionals make the switch from peak to loudness. RTW's Head of Product Management is part of PLoud and actively took part in creating EBU R128.
Many european countries moved on to mandatory introduce EBU R128. In Germany, it became binding end of August 2012.
In parallel, other continents published comparable standards, different in details, but essentially all based on the k-filter according to ITU-R BS.1770.

to PLoud web site at EBU >

In this year, RTW got certification for ISO 9001:2000 from TÜV Rheinland Cert GmbH. ISO 9001 is an internationally recognized standard for quality management. RTW's certification demonstrates adherence to documented quality processes and procedures that ensure ongoing improvements in the development, manufacturing, and support of the company's products.

to RTW's certificate at TÜV Rheinland >

After 42 years of successful business activity, the management of RTW was handed over to younger hands. With Andreas Tweitmann, the owners found a successor ensuring full continuity for the company, all customers, business partners, and employees to guide RTW and its employees safely into the future.

Metering and monitoring go hand-in-hand - so why not combine all necessary components in one unit? RTW has implemented this concept in the SurroundControl SurroundControl 30900 and created a versatile tool for comprehensive acoustic monitoring and metering of surround signals. SurroundControl 30900 combines the metering functions of the RTW surround display devices with the control functions of an eight-channel monitoring controller to reap the benefits of an unusually high-performance system. The peak meter, analyzer and loudspeaker management functions complement each other perfectly.
Some years later but before loudness regulations became mandatory, the measuring functions received flexible extensions to enable metering acc. to the loudness recommedations as till then known and for later adjustments to changing specifications. This also went with the enhancements of the hardware and the audio inputs. 30900 changed to SurroundControl 31900.

The increasing digitalization in many fields also led to changed workflows in audio production. Fields increased, in which not only educated audio engineers had to care about the best sound. Therefore, RTW developed the univeral, compact, and easy-to-read table-top peak programme meter 1204A (analog) and 1205D (digital) as reference instruments for precise, standard conform level control and mono compatibility monitoring in audio workstations, control rooms, video postproduction suites, PA systems and others. With these devices, less experienced users were also able to control their audio in an optimal way.
The image shows model 1205D-BL with blue table-top housing, high-precision three-colored LED bargraph display for level, peak level, and loudness, additional phase meter, status displays, and calibration mode for precise level adjustment.

Keeping tabs on all the parameters of surround sound projects is a lot of work for sound engineers producing in stereo so far - there are five channels contributing to the surround effect, and their relative levels, loudness balance and correlation have to constantly be monitored. To do this effectively, the RTW engineers developed an instrument that shows more than the individual channels, one that provides the relationships between all its components - the RTW Surround Sound Analyzer. Firstly integrated into SurroundMonitor 10800X, the Surround Sound Analyzer calculates the dynamic relationships between the parameters of all channels and displays them in a graphical image of the surround sound space. Everything needed can be seen at a glance, including loudness relationships, the positions of dominant and phantom sound sources, centre channel presence and signal components with negative correlations.
Including the 10-way multi-correlator (in addition to Surround Sound Analyzer), the 31-band RTA, the real-time audio vectorscope and the AES/EBU status monitor, SurroundMonitor 10800X provides further instruments for comprehensive audio monitoring. These instruments have been modified over the years and are available with the current devices and software products.

to the interactive demonstration of the Surround Sound Analyzer >

Surround and multichannel recordings are making high demands on clearly arranged screen layouts of audio vectorscopes. Beside levelling multi channels, also the phase correlation of numerous channel pairs have to constantly be monitored, especially the front and rear channels. Phase problems or other failures might be caused by wrong settings of microphone arrays commonly used in surround recordings.
RTW created the SurroundMonitor 10800 providing an easy-to-read display which is cleary divided into two separate sections presenting cleary arranged elements:
On the right, the 8-channel multi-norm peakmeter is displayed.
On the left, the phase meters and the real time display of level and phase relationship on a 5-channel audio vectorscope are shown. The arrangement of the four phase meters of channel pairs L/C, R/C, L/R, and LS/RS above and below of the audio vectorscope allows a clear identification and gives an idea whether the overall balance of a surround recording is good or not.

For solving many of the problems with interfaces of digital and analog audio systems, the DistriCon series was developed and launched as a flexible solution. Eurocard modules for distributing, converting, and monitoring digital audio signals matched into any 19'' system environment or were combined in the DistriCon system racks to functional units.
Beside 24 bit A/D and D/A converters as well as sample rate converters, the module range also included distributors for AES/EBU signals, digital monitoring modules, digital faders, format converters, and other special functions.
DistriCon could be used for any application, as a "lonely" converter hidden in the rack or as a big multi-channel converter system in a central control room. The units of the DistriCon series was availble in two product lines: as freely configurable module system DistriCon modular or as completed elementary equipeed 19"/1U rack cabinet DistriCon compact.
The image shows DistriCon modular system rack 1200-3U16 including an internal bus board for monitoring, 8 A/D and 8 D/A converters, and power supply.

Depending on the experiences with constructing audio monitors and getting much better color displays, RTW developed the PortaMonitor series, which became very popular among its users. Part of the series were also versions for displaying multi-channel signals. Furthermore, a visually appealing housing was created.
The images shows PortaMonitor 1064 with 4-channel display.

The selection of a panel-mount or table-top peakmeter normally follows a specific configuration with clear defined requirements. For audio engineers who have to meet different requirements for different audio productions, RTW developed the stereo audio monitors, which are able to display different instruments with comprehensive adjustable parameters on LC color displays. So the first units already provided audio vectorscope, phase meter, multi-norm peakmeter, AES/EBU status display or real time analyzer (RTA).
The undated image of unknown origin shows MultiMonitor 1066. Some of these units are still in operation today.

At the end of the eighties, digital audio recorder came into the market. They were able to record audio data to digital magnetic tape (DAT - Digital Audio Tape) providing the same audio recording format and the same or better audio quality like audio compact discs. But in the consumer market they didn't become accepted. Because of its considerable higher quality and comfort compared to other recording media, DAT recorder were often used in professional environments like audio studios.
With the remote controls named DAT-Control constructed by RTW, the audio engineer was able to control all recording and control functions of a DAT recorder directly from his place at the mixing and control desk. Beside the desktop DAT control shown in the image, there were also versions in compact 40 x 190 mm standard panel-mount metal cassettes available for mounting into meter bridges.

Very early, RTW was concerning with finding a solution how an audio engineer can produce a constant loudness impression in a safe way independently from different program material and production conditions. To give a measure for this in form of a reference value, RTW firstly created devices with loudness display. Therefore, the loudness display of the RTW peak program meters (peakmeter or PPM) is generated by analyzing the two predominant audio signal parameters, frequency and impulse. This is done by applying physiological principles analog to the processes which take place in the human ear. The signals are run through a filter circuit which uses a special filter curve developed and optimised in compre­hensive experiments carried out at the Funkhaus Berlin. The loudness meter design is based on data generated in a number of empirical listening tests.These tests were carried out with a large group of pro audio people - tonmeisters and sound engineers - each of whom participated in a series of listening sessions.
Further information can be found in the former publication Loudness Display.

In this year, RTW launched its Timer series mounted in compact 40 x 190 mm standard panel-mount metal cassettes. These studio stop clock units with up/down timer mode were used to capture, pretend, stop, store, and sum time periods during production and post-production up to the precise display of standard time synchronized to the DCF radio time signal.
The image shows Program Timer 1195 providing a centronics-compatible interface for logging and printing of data.

In 1987, RTW tooks over the exclusive distribution of the high performance audio analyzer and audio test instruments of Audio Precision® for Germany. System One, the first easy to use audio analyzer with PC controlled architecture, also rapidly became the industry standard in audio test in Germany. System One was followed by other high performance analyzers, which were and are able to run comprehensive measuring sequencies in very short time. In 2008, RTW committed the distribution to its successor Admess.

The first peakmeter for digital input signals was model 1150DA. It was used to receive and display signals of Sony-PCM-1610/1630 formats and could be operated with horizontal or vertical digital scale (-60 to 0 dBFS) or extended horizontal or vertical DIN scale (-50 to +10 dB). It consisted of two parts: the panel-mount peakmeter in compact 40 x 190 mm standard panel-mount metal cassette and the panel-mount 40 x 40 mm remote control. These parts could be mounted side by side, one below the other, or, depending on required space, separately from each other. As 1150DA-T, the unit was available in a table-top housing with integrated power supply and connection cable to the processor. The panel-mount peakmeters for digital AES/EBU signals developed from these units in the following years.
The undated image of unknown origin shows 1150DA with DIN scale and separately mounted remote control.

The dissemination of the chromium dioxide compact cassettes (CrO2) results in a greater need of high-speed copies of this tape type. Because of the altered technical characteristics of the chromium dioxide cassette compared to the common normal cassette type, RTW modified existing products and adapted them for the German market. So high-speed copies of the chromium dioxide cassette could be done one-to-one in best quality. Also copying from chromium dioxide cassettes to normal cassette type and vise versa was possible.
The image shows the 4-channel version RTW Copier Studio M being able to duplicate all tracks of the original cassette simultaneously.

RTW was engaged in digital audio technology very early, so Sony®'s Digital-Audio-Processor PCM-F1 NTSC (upper unit in the image) became part of the product range. This device was also available as a modified version in order to connect an Analog & Digital Interface (below left) developed by RTW. This interface expanded the functions of PCM-F1 for studio applications to adjust the inputs and outputs for balanced +6 dBm connection technology and to allow direct digital copies to Sony®'s professional Processor 1610. The interface also could be used as power supply for two portable Sony® Betamax Videorecorder SL-2000 NTSC (below right).

Launched in 1984, the 1100 series peak level meters came in a compact 40 x 190 mm standard panel-mount metal cassette providing several versions with different features. Beside a unit with pure peak level display, other models were equipped with additional peak memory, switchable +20 dB gain, and build-in correlator for monitoring the phase relationship between the displayed channel.
Common for all units was the high-resolution gas plasma display with two 201-segmented (127 mm scale length) resp. two 301-segmented (150 mm scale length) bargraphs to ensure a highly precise display of the measured signal values. The measuring range of the horizontal or vertical sandwich scale followed the DIN 45406 recommendation, but also was extended. Later on, models including British IIa and Nordic N9 scales were added.
The image shows a 1109 with extended horizontal DIN scale (301 segments, measuring range -50 to +10 dB).

RTW moves to its own newly built premises in Koeln-Chorweiler, a district at the suburbian area of Cologne.

RTW takes over the exclusive distribution for TELEX® high-speed tape and cassette copier systems, Audiocom Intercom systems, headphones for education and language training, and further accessories. Additionally, made-to-measure cassettes, branded audio tapes and accessories are part of the distribution fields.
The image shows TELEX Duplicator 300. When configured with additional modules, the unit was able to copy up to 960 C60 cassettes and/or 240 one-hour tapes during an eight-hour workday.

A separate table-top unit in a plastic housing with integrated power supply developed from the combination of panel-mount units with metal table-top housings. The legendary 1206 was born and launched in 1978.
The image shows a 1206 as it was produced in 1980. Later on, the unit was equipped with sliding scales for switching between different display standards, or horizontal and vertical orientation.

A first prototype of a peak level meter with digital controlled bargraph display in a panel-mount housing was presented in 1974 at Photokina in Cologne. Beginning 1975/76, the devices went into production typed 1.214, 1.215, 1.216, and 1.217 with different scale lenghts for vertical or horizontal mounting.
The image shows a horizontal version in a table-top housing.

The need for reliable display instruments led to the development of the first peakmeter.
Unfortunately, no further details or photos have survived.

In 1965, Rudolf Twelker founded RTW as a service company for the repare of radio and television devices in Cologne, Germany. It also served as an authorized repair shop for Revox reel-to-reel tape decks. Furthermore, antenna construction was part of the company's activities.