Taustajännitettä

Taustajännitettä refers to a concept in audio engineering and acoustics, often translated as "background voltage" or "bias voltage" in English. It generally describes an undesirable, low-level electrical signal that is present in an audio system even when no intentional audio signal is being sent. This can manifest as a faint hiss, hum, or crackle that is audible when the volume is turned up in the absence of input.

This background voltage can originate from various sources within the electronic components of an audio device. It can be due to thermal noise generated by resistors, noise from active components like transistors and vacuum tubes, or electromagnetic interference (EMI) picked up by cables and circuitry. Power supplies can also contribute to background voltage through ripple or noise.

In high-fidelity audio systems, minimizing taustajännitettä is a crucial design goal. Engineers employ techniques such as careful component selection, shielding, filtering, and proper grounding to reduce these unwanted signals. The signal-to-noise ratio (SNR) is a key metric used to quantify how much the desired audio signal stands out from the background noise. A higher SNR indicates a cleaner audio signal with less audible taustajännitettä. While completely eliminating all background voltage is practically impossible, the aim is to reduce it to a level where it is inaudible or unnoticeable during normal listening.