A More Formalized Description of System Faults
In the previous post “What Absolute Sound?”, when trying to describe various issues with systems with more and the minimum number of components in the signal chain, the idea of describing a system as a chain of Filters and Mutations came up.
Since a Filter is just another Mutation, one can describe a system of ‘n’ components as a sequence of mutations M on the signal coming from the source media:
Mtotal = M1 * M2 * … * Mn
Where M1 is the mutation caused by component #1, M2 by component #2, etc. A component can be an amp, cable, speaker, the room… everything that affects the sound of the system. A typical mutation might be one that removes some dynamics, it might exaggerate note attacks in the midrange, it might shift the harmonics a little bit in the upper frequencies, etc. or it might do all of these things.
For example: if M1, a cable, is lean and only lets through 90% of the bass and M4, a preamp, is also lean and only lets through 70% of the bass, and all other components are bass neutral, then the system lets through 0.90 * 0.70 = 63% of the bass.
A “balanced” system is one where all frequencies are mutated the more or less same way.
A “pseudo balanced” system is one where various frequencies that are mutated significantly by one component are ‘almost’ counterbalanced by a mutation in another. I.E. if one mutation is bright, exaggerating the attack of treble frequencies, then another would have to be rolled off on top, or in some other way unexaggerating the attack in the treble somehow so that, overall, the frequencies in the treble end up being mutated the same way as the frequencies in the midrange and bass..
An “optimal system” is one where the mutations M are very small and have no significant effect [in practice, there is always a slight filtering of the signal as it winds itself through cables and connectors and various cir5cuities. Also a slight leanness or bass emphasis might be present and detectable. All else being more or less mutation free or sufficiently nuanced as to defy easy detection].