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All that info can be made available at a higher level. The only reason to do it at a lower one is to reduce surface area where software bugs could destroy the s

All that info can be made available at a higher level. The only reason to do it at a lower one is to reduce surface area where software bugs could destroy the speakers. > Our implementation, speakersafetyd, monitors feedback signals from the amplifiers, estimates speaker voice coil temperature using a two-stage thermal model, and reduces the hardware speaker volumes when the speakers get too warm. We also have kernel-side interlocks to disable or limit speaker volumes if speakersafetyd is not running or non-responsive. This is the only part that seems to need to be low-level, anything else could be done at a higher one, generally EQ type settings like 'loudness'.

hedora 3y ago
Existing laptops provide that higher level of abstraction, and audio quality is uniformly garbage. It’s likely much easier for the open source people to do the work to deal with the underlying physics once, and then port it to all hardware. The laptop models are all essentially the same (they have a few electromagnets, cones and a few sounding boards). Each one has different parameters in their mostly-linear response curves. My guess is that after the first few models work well all the others will rapidly fall into line. Something similar happened with printers 20 years ago. The open source stack implemented state of the art dithering and font hinting once and ended up producing higher quality output than the commercial windows drivers for the same printers.
lonjil 3y ago
> This is the only part that seems to need to be low-level, anything else could be done at a higher one, generally EQ type settings like 'loudness'. But that already is the only part that is low level. The EQ stuff is done with PipeWire.
a-french-anon 3y ago
Very interesting, but how accurate is that model? It's worth mentioning that even pro audio brands with deeply integrated DSP (e.g. Neumann or Genelec) still use physical thermal sensors. Why? Who knows, maybe to squeeze the last bit of SPL before damage. I suppose that having more than one driver (thiu voice coils with differing sizes and limits) makes things more complicated, too. I guess/hope amplifier clipping is also accounted for, as the sudden rise in harmonic content can easily damage tweeters (which I think macbooks have?).

hedora 3y ago

Existing laptops provide that higher level of abstraction, and audio quality is uniformly garbage. It’s likely much easier for the open source people to do the work to deal with the underlying physics once, and then port it to all hardware. The laptop models are all essentially the same (they have a few electromagnets, cones and a few sounding boards). Each one has different parameters in their mostly-linear response curves. My guess is that after the first few models work well all the others will rapidly fall into line. Something similar happened with printers 20 years ago. The open source stack implemented state of the art dithering and font hinting once and ended up producing higher quality output than the commercial windows drivers for the same printers.

lonjil 3y ago

> This is the only part that seems to need to be low-level, anything else could be done at a higher one, generally EQ type settings like 'loudness'. But that already is the only part that is low level. The EQ stuff is done with PipeWire.

a-french-anon 3y ago

Very interesting, but how accurate is that model? It's worth mentioning that even pro audio brands with deeply integrated DSP (e.g. Neumann or Genelec) still use physical thermal sensors. Why? Who knows, maybe to squeeze the last bit of SPL before damage. I suppose that having more than one driver (thiu voice coils with differing sizes and limits) makes things more complicated, too. I guess/hope amplifier clipping is also accounted for, as the sudden rise in harmonic content can easily damage tweeters (which I think macbooks have?).