22.11.2017

Dear Sound Enthusiast,

Like many other people, you may have asked yourself what makes an audio electronic device sound great. You have heard units with excellent specs, but couldn’t confirm this by listening. Nice numbers – no sound. Is this an exception, or can we “read” any information about sound quality by reading the specs? From my side, I must tell you that you can’t. Let’s have a look at some of the usual tech specifications picking out two typical parameters: frequency linearity and distortion.

Frequency linearity provides no definitive answer here. It can be influential in evaluating the character of a loudspeaker or microphone (mechanical mechanism), but not an electronic device. Here, absence of low end or too much “mid” would be regarded as a “fault”, requiring the device to be sent for repair. Even the cheapest, poorest-sounding electronic device will be “linear”.

Distortion: the quantity of total harmonic distortion, in terms of percentage, is also irrelevant. The 2nd harmonic sounds nice, the 9th sounds horrid. 1% of the 2nd can just be heard as a slightly more “juicy” effect; 0.02% of the 9th can also just be heard as a dissonant harsh effect. Audio products with extremely low THD should also be avoided. These low values result from extreme negative feedback, which makes the sound flat and boring by cutting down the attack time. Few other parameters refer so specifically to the ”sound” itself.

The most important “parameter” for sound excitement, musical emotion, purity and accuracy of information is the transient behaviour of any electronic device, i.e. how fast the electronics can accelerate and stop. However, you will not find a number for the transient in any spec. Why? Firstly, transient velocity is difficult to measure, although it’s easy to hear. There’s no “standard” so that numbers can be compared. Secondly, the industry appears to have little interest in writing or speaking about this, seeing that most devices are built with cost-effective integrated circuits but poor transient behaviour.

All SCHERTLER electronic circuits are built renouncing any negative feedback in order to favour an extremely fast transient behaviour. This “mechanism” is difficult to engineer, but any people “in the know”, such as sound techs and musicians, can tell you something about the 3rd dimension: the transient time brought to the maximum possible acceleration. Check out an ARTHUR module to hear what I have just tried to put into words.

Yours sincerely

Stephan Schertler

(photo by Outsiers)