In order to go about successful audio monitoring, it is important to remember the ultimate goal, which is to accurately predict the listening experience of the audience, and taylor a final product which will perform desirably under those supposed conditions. It seems so simple and so obvious, but our modern times have created a climate where the playback scenarios are vast, and the need to compromise in order to create a mix whose listenability across a greater number of equipment types is a real concern. Because of this, the ability to cross-reference audio through different speakers, headphones, down-mixes, and other options means that, more and more, clean transparent monitor controllers are an essential tool in any type of working environment.

In order to fully grasp the needs of a modern monitor controller, it is important to consider the evolution of these tools, or even the evolution of monitoring in the first place. Think back to the days when monitoring a recording first became possible, and what a profound impact it had on the recording industry. At the dawn of the recording process, the first time anyone involved with the process ever heard what was being recorded was after the master was already cut. In the days of acoustic recording to a wax cylinder, the process was mechanical, not electrical, and all you could do was take it on faith, that the recording was being captured successfully.


The story of monitoring really goes back before recording, though, all the way back to the early days of radio. Before the invention of loudspeakers, electrical sound was heard exclusively through primitive moving-iron headphones which presented quality sufficient for deciphering speech, at best. Knowing that the audience would be listening to these types of headsets, radio broadcasters would monitor themselves using the same type of equipment. The first “speakers” were basically these types of transducers attached to cones or horns for acoustic amplification.

The age of actual dynamic moving-coil loudspeakers wouldn’t dawn until the 1915 when the Magnavox was introduced. This speaker led to an improved design from Chester W. Rice and Edward W. Kellog introduced in 1925, which served as the basis of the modern dynamic moving-coil loudspeaker. While these speakers, introduced into radios and phonographs in the late 1920’s, greatly improved the sonic experience in listeners’ living rooms, professionals still primarily relied on headsets for monitoring through to the 1930’s. It would be the motion picture industry that would really push loudspeaker monitoring into the forefront.

By the end of the 1920’s, talking movies had taken over Hollywood and soon, artistic trends created a common code for sound in movies. The idea that dialogue should be the focal point, and that ambient sounds should create a backdrop, led to the idea that recording these elements separately and mixing them together selectively would be advantageous. Dub stages were built using characteristics in size and acoustic conditions similar to those found in theatres, in order to accurately predict the audience’s experience. The monitoring technology on these stages quickly began to resemble modern cinema loudspeakers, commonly featuring multiple 15” woofers, high frequency compression drivers and radiating horns with wide dispersion patterns.

James B. Lansing and his Lansing Manufacturing designer Dr. John Blackburn had stepped away from their usual business of designing speakers for radios and phonographs in order to participate in the development of the “Shearer Horn,” a collaboration between several manufacturers which resulted in one of the better-sounding cinema speakers of the times. Lansing and Blackburn applied what they had learned in developing this large cinema loudspeaker to create the Lansing Iconic, a scaled down full-range speaker with a single 15” woofer in a bass reflex cabinet and a compression driver with a multi-cell horn on top. The intention was to provide an accurate studio monitor for use in the monitoring booths of recording studios and as its popularity quickly spread, a blueprint for the studio monitor had finally been established.


Through the 1960’s and 70‘s the audio industry would see the rise of magnetic tape and multi-track recording in music studios. Because of the new level of decision-making that multi-tracking provided, the role of monitors in the music world finally reached a status equivalent to that which had been seen in the cinema world’s dubbing theatres for decades. New experimental ideas like engineers requesting separate monitors to reproduce the sound of each of the four tracks on recorder, demonstrated that new expectations for monitoring equipment would lead to the production of new purpose-driven gear. The growing popularity of stereophonic music furthered that notion. The new custom consoles being built for studios with increased numbers of faders, onboard equalizers and compressors now, also featured a centralized monitor section which sat right in the “sweet spot.”

In the days of mono, a single, large monitor could be placed anywhere in the control room. For stereo, similar, large, far-field monitors in utility cabinets or mounted right into the wall, began serving as stereo pairs. When judging the stereo image through far-field monitors in an era before acoustic treatment had been fully grasped, the perception of mix was greatly influenced by the room. Because of this, JBL introduced the 4310, a small, bookshelf-style speaker box which housed a woofer and a tweeter. The intention was to place these monitors right on top of the meter bridge of the console. This near-field monitor position removed a significant amount of the room from the listener’s sonic experience, because the direct sound was loud enough to mask the early reflections from untreated walls. In larger studios where budget allowed it, the 4310’s served as a secondary reference to the large wall-mounted “mains.” Building a mix that translated well across the different monitors meant that engineers could sculpt tones that would serve audiences with hi-fi stereo equipment, and smaller speakers, alike.

This trend continued as popular consoles from Neve, SSL, Harrison and others provided two or even three monitor selection switches in their popular consoles. It became common to reference a large main monitor pair, a flat, accurate near-field pair, as well as a miniature reference pair which portrayed the worst-case consumer listening scenario. The Auratone 5C quickly grew in popularity for this purpose. It was a small box containing a single driver which was crowded and mid-rangy. If a mix was able to sound clear on a 5C, it could probably sound good on anything. Some engineers even began traveling with their own real-world reference monitors, choosing different consumer hi-fi speakers and becoming familiar with their sound. For example, the Yamaha NS-10, a bright, awful-sounding hi-fi speaker became popular in one circle of engineers. The common practice was to tame the tweeter by attaching a very particular number of ply’s of a certain brand of toilet tissue as prescribed by Bob Clearmountain. This led to Yamaha issuing a high-frequency compensated NS-10m studio monitor, which, for no reason in particular, remains the new 5C in many studios.


As much as mixers were recognizing that they needed to regard typical consumer listening conditions, they also realized that this was only one of the truths of a mix to be evaluated. The other was the consideration of what was actually being printed onto the master tapes. The market for hi-fi consumer stereo equipment only grew as quality of available components improved. Creating a mix which would satisfy listeners across a breadth of hi-fi systems required the most acute critical listening, using equipment which was devoid of coloration and character. Mixing consoles of the time were sought after for the signature tone of their circuits and amplifiers. The problem was that those same colorful circuits that were adding flavor to the channels and mix busses would also color the amplifiers in the monitoring path, causing engineers to overcompensate EQ adjustments. Even more than mixers, engineers from the newly-born mastering industry began to drive the market for honest and accurate equipment.

Mastering suites began coupling traditional absorption with newly-devised acoustic diffusion techniques to level out the frequency response. Monitors whose housing, drivers, and crossovers were designed for the flattest sound were paired with equally transparent amplifiers. To go along with these new tools, equipment designers like Chris Muth began building custom transfer consoles for mastering engineers. The design of his famous desks built for Sterling Sound transmitted signal through clean, colorless circuits for routing between processors. These transfer consoles were paired with custom monitoring controllers with custom DA converters which fed the monitors with as faithful an image of exactly what would be printed onto the release medium as possible. Muth’s monitor controllers provided the ability to perceive the intricacies of a mix with the utmost accuracy, providing the confidence that there would be no surprises regardless of possible playback scenarios.


With the growing popularity of digital audio in a professional workflow, engineers began testing the limits of just how far they could depart from traditional setups. The realization that a DAW system could serve as more than just an editing tool, but actually replace multitrack recorders and mixing consoles led many studios to abandon their physical mixers. With a whole box full of tools gone, it wasn’t long before they realized that a mixer was more than just EQ’s, dynamic processors and a summing amp. The center section of any console provided essential tools like talkback, headphone cues, and the ability to route signals to and from various sources and destinations, not to mention the volume control. Not only did engineers see a need for these resources, but they demanded that these tools be provided with greater sonic transparency than the colorful consoles of old. It’s not really surprising that big names who had the means to commission custom gear turned to Chris Muth, who had proven himself in the arena of clean circuitry already.

Realizing that it would be more practical to design a line of products rather than continuing to build one-off custom designs, Muth and business partner Bob Muller began building Dangerous Music rack-mounted monitor controllers in the image of the original Muth Monitor Controller. It didn’t take long for other manufacturers to catch on and realize the market for this type of equipment, which cannot be overstated. The reality is, it doesn’t matter what DAW, interface, acoustic treatment, or monitors you buy if you are not passing signal to those monitors accurately. The only way to make a mix which is universally compatible with home stereos, car stereos, computer speakers, headphones, earbuds, and every other conceivable playback device is to know what the mix really sounds like.

While Muth’s designs are no longer the only name in the game, that doesn’t mean that all monitor controllers are created equal. When doing your research and shopping for the right monitor controller to fit your needs, remember how modern concerns, as well as classic monitoring goals should be considered:

-It is important that you have access to the cleanest possible circuit path between your sources and your monitors. If onboard DA converters are provided, they should be clocking and converting your signal with the highest possible fidelity, or else the entire conception of your mix will be skewed.

-Cross-referencing your mix requires consideration of how that mix will sound through club PA’s, car stereos, home stereos, computer speakers and even tablet and cell phone speakers. Speaker selection should be executed with clean switching which will not spike voltage or pop when switching.

-It is important to also have an accurate path to reference your stereo image on headphones, as more listeners will now, more than ever before, experience your mix via portable media players.

-Down-mixing from surround, to stereo, to mono must be performed during the mixing process to ensure cross-compatibility across different consumer playback scenarios. The summing circuits performing these functions should not cause excessive distortion or coloration.

All of these important goals have been addressed in different ways by the products in the Dangerous Music monitoring line. With a selection of tools that range in price and features, the equipment you find here should serve a great variety of needs with equal satisfaction. From the portable new Source, designed with the laptop-based engineer in mind, to the popular D-Box, which combines an analog summing mixer with a monitor controller, or the flagship Monitor-ST and SR, each device is built with the highest quality components and level of excellence in engineering made famous by the classic Muth mastering tools. Whether you choose Dangerous or go elsewhere, show your mixes the consideration that they deserve and don’t take this decision lightly. It is the difference between making confident adjustments to your mix and just guessing.