Important tips for improving sound quality in audio systems!
- Using an AC power strip with several outlets to connect several audio
devices to AC power can derate sound quality if each device is not
phased. Turning AC plugs 180° while measuring The AC voltage between the
Audio signal ground and the house ground shows higher or lower AC voltage
induced into the signal ground compared to the house ground. The higher this
undesired AC voltage is the more it derates the sound quality.
- You need a high impedance multimeter set to AC voltage measurement.
Usually up to 100V AC can be on the signal ground. Set the Multimeter
accordingly. Remove all connections between devices connect one side of
the multimeter to house ground and one side to the Audio connector ground
of the device to test. Turn on the power to the device. Measure the AC
voltage. Turn the device off and turn its power connector 180° in the power
strip. Turn on the power and measure again. Leave the power connection where
less voltage is injected. I use my wifes fingernail polish, red, to mark the
power connector and the power strip so that I know how to turn it to plug it
back in if removed.
- Repeat for each individual device. Then reconnect all audio cables between
devices. Now repeat the procedure for the wall outlet to the power strip.
There will be less influence than before with the individual devices but a
difference should be noticeable. Put fingernail polish on the wall outlet and
on the power strip plug to note the best position.
- Audio cables definately do effect sound quality. But to hear the difference,
you have to have good equipment. Ac power phasing on the equipment must be done
before testing cables. Do not trust your ears. Your brain influences
your hearing at least 10 % which is more influence than most cables have. The
standard hearing curve for normal hearing is very unlinear, with more than
12 dB difference according to the loudness and frequency of the sound on the
ears. To work around this, put your best recording in the player and start the
recording. Set the loudness to a level that sounds ok and leave it there. Always
use exact this loudness level. Does one cable set sound better or only different?
Exchange the cables and try again.
Leave at least an hour between and repeat. Good cables are more powerfull, have
more depth, the sound stage is larger and the different sounds are simply more
accurate. Music instruments, with wideband resonance, such as piano, guitar,
drums etc, have more resonance and the sound is simply more real! The easiest
difference that is most noticable is timing. Cheap cables have bad timing.
All instruments that are hit, like drums, top hats, etc. sound as if the sticks,
hammers etc. are wrapped in cloth. The sound has stretched out timing, and is
unreal and without the live feeling.
- By comparing equipment and cables, do not listen for hours trying to hear
differences. You will only get 'head influenced' results because the ears and
brain will get tired! If a difference is not at once noticable, do not push it,
go away and try again later. I have fallen into this trap quite often! Listening
early morning and later evenings is best, because mornings your ears and brain
are functioning better. Evenings after resting is also good while usually AC
power is cleaner after 9:00 PM