Interesting posts indeed, but some very crucial information needs to be brought to our attention.
Electronics seems to be left out of the "equation", which is quite regrettable. This post will not be
exhaustive but will cover an example or two. Of course it involves listening.
1. One single part value anywhere in an electronic component, or crossover, can bloat the bass,
giving the appearance of lacking bass control. Improper internal terminations and
poor materials in coupling capacitors are prime examples, as the affect all octaves in audio, not
less than 1/3 octave.
2. Improper design of the power supplies/filtering stages in components can either fatten or reduce
the bass. Types of filter capacitors, such as electrolytic negatively affect bass response. This is just
basic electronics engineering.
a. Because of poor power supply design, tube designs often tend to bloat bass.
b. Solid state tends to fatten the bass due to large electrolytic capacitor necessity,
with high DA and ESR.
c. Fortunately, global negative feedback (GNF) in both a. and b. tends to lower the output impedance
of an amplifier, increasing the damping factor, but varies with frequency. The result is not really flat
response. Also, again, this involves more than 1 octave, let alone 1/3 octave.
d. However, with proper design, amps may obtain very tight bass without GNF. But then types of
distortion increase.
3. The "matching", itself, between amplifier output to speaker, including speaker wire will
affect damping, thus under damped or over damped bass response. This involves more than
one octave, let alone greater than 1/3 octave.
4. DC coupling between electronic stages almost always creates a boosted bass response, not flat,
accurate response as one would think. This situation also covers many octaves.
(There are certain situations where dc coupling actually causes reduced bass response.)
5. There are many other forms of distortion besides harmonic (and IMD).
The definition being any alteration of the musical information.
6. Although speakers/rooms cause deviations in response, they seldom exceed 1/3 octave bandwidth,
except in the bass region. For example in contrast, 20 to 40hz is an octave vs 5khz to 10khz as
an octave. Frequency response deviation is one form of distortion. Can one imagine if we perceived
every single dip and peak, how awful the playback would sound.
The wider the bandwidth deviation, the higher number of harmonics from a voice/instrument are
negatively affected. That is why although the specs look so good for an electronic component, the
effect so great. A distortions in an electronic component almost always affects the entire audio
spectrum, approximately 10 octaves, and even beyond.
For instance, +/- 0,1db from 20 - 20khz, a deviation in the approximate -54db range, means
virtually nothing as 1 part in a million perception is some -114db to -120db range. Obviously
listening is involved.
The major point is that electronic components should be right near the top of the list. The electronics
is worse than one thinks. Although they don't produce a huge splash in an area or two, as
speakers/rooms do, an electronic component's other negatives effects often occur across the entire
audio spectrum.
A bad component(s) in a good room still sounds bad. Just one bad electronic passive part can destroy
an otherwise good sound. That is why I do a prelim in the room acoustics, check electronics for accuracy
in absolute terms (or visa versa), then work with speakers and source(s), and then deal with room
acoustics again. It is back and forth with source/speakers.
If one does not get the electronics right, then the speaker/room placement/treatment(s) won't be proper
either. Of course it is easier for a designer as they can adjust parts/components etc that others often cannot.
cheers
pos