Christian Luther

Author Archives: Christian Luther

Research & Development Engineer in the audio industry and the creator of The Science of Sound.


One Word To Confuse Them All

In the world of audio, nothing seems to trigger more reflexes of fear than “phase issues”. The reason is probably that it describes a rather scientific concept which is sometimes hard to relate to the reality of music signals. Also, there are three very different phenomena that are often confused by using the same word for all of them.

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Analog Summing Demystified – Part 1: An Introduction

Today, we are entering the dangerous territory of one of the most reliable causes for flame wars on audio forums: analog summing boxes!

It is essentially a recreation of the part of an analog mixing console that actually mixes all the channels together. The promise is to provide a bit of “console sound” while otherwise still working “in the box“. In this two-part series, we’ll analyze analog summing circuits thoroughly and try to find out what there is to it. Today’s article is about introducing you to the basics of analog summing circuits and the first of two typical types of these circuits – the passive summing network. Next week we’ll look at the active summing network and think about how we can apply what we learned to think outside the summing box.

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Hearing: The Blessings and Curses

For working with audio, we have two tools at hand to assess what is going on: hearing and measurement. I already posted an article about the blessings and curses of audio measurement, to increase awareness about what we can and cannot achieve with it, and about the several traps installed along the way. And necessarily there must be a complementary post that deals with the even more important tool we use: our hearing. Continue reading


Quantization Noise and Bit Depth

In this early stage in the life of The Science of Sound, I’d like to cover some of the basics especially of digital audio, as these are a recurring source of confusion in many discussions. Today we’ll start with covering the „vertical“ dimension of digital audio: quantization noise and bit depth.

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Audio Measurement: The Blessings And Curses

There’s no question: the single most important judgement tool for audio professionals are the ears. There is actually no measurement instrument in the world that is as versatile, fast, convenient and intuitive. And after all, music is made for ears, not measurement instruments. But there is also no instrument that can be as imprecise, mood-dependent and subjective as the ears. Thus, audio engineers and equipment developers alike need a complementary tool of judgement, to overcome these disadvantages. This gap is filled by a variety of audio measurement tools available, like spectrum analyzers, loudness meters, oscilloscopes and many more.

Here on The Science of Sound, we will rely heavily on measurements as we dig deep into the guts of our beloved audio tools and processes. But it’s important to be very clear and mindful about what we can and cannot achieve by relying on measurements. So here are 4 blessings and 4 curses of audio measurement.

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About JENS: Sound Localization In The Median Plane

In a lot of ways, music mixing is all about creating a spatial impression and placing every instrument in its specific position in a virtual space. Besides the usual suspects like panning and interchannel delays for positioning in the horizontal plane and reverberation and equalization techniques to create a sense of distance, there is a third dimension of sound localization that is often overlooked: the median plane, which means localization in the front, back, above and below directions. Let’s have a closer look at the human abilities to distinguish these directions and at my neat FREE plug-in you can use to fool the ears a bit more when mixing.

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