Brusgolvet

Brusgolvet, literally the “noise floor” in Swedish, is a term used in acoustics and audio engineering to describe the lowest level of background noise present in a system when no useful signal is being fed into it. It represents the baseline from which all quiet audio must rise to be audible above unintended noise.

The noise floor arises from multiple sources, including thermal noise in resistors and semiconductors, shot noise, flicker noise, and power-supply ripple. In digital systems, quantization noise and clock jitter also contribute. External factors such as electromagnetic interference, grounding, and cable quality can elevate the measured brusgolvet in practice.

Measurement and units vary by context. In digital audio, the noise floor is expressed in decibels relative to full scale (dBFS); a lower number indicates a quieter floor. High-end equipment may reach below -90 dBFS, while consumer devices often sit in the -60 to -70 dBFS range. In analog contexts, noise is described using dBu or dBV, or through the signal-to-noise ratio (SNR) relative to a reference level.

Significance lies in dynamic range: the gap between the maximum usable signal and the brusgolvet determines how well quiet details are preserved. Noise floor management is crucial in recording, mastering, and playback, influencing gain staging, shielding, power supply quality, and the choice of components. Effective reduction of the brusgolvet enhances clarity without introducing distortion.

See also: dynamic range, signal-to-noise ratio, quantization noise, dBFS.