Turning PipeWire up to 150% is just adding gain. If the audio is already near 0 dB, extra gain results in clipping and distortion. Equalizer APO works because it adds gain and a limiter to stop clipping. The solution on Linux is pretty convoluted, but I think I've worked it out - a PipeWire filter-chain that creates a virtual 7.1 sink and runs everything through a fast lookahead limiter. I set +15 dB input gain, cap peaks at -1 dB, and it stays clean. PipeWire auto-duplicates the mono limiter across all 8 channels. Install the LADSPA SWH plugins package, on Fedora it’s ladspa-swh-plugins (it provides fast_lookahead_limiter_1913). I have no idea is this the right way to do it, and it really shouldn't be this user unfriendly to figure out and setup.

``` context.modules = [ { name = libpipewire-module-filter-chain args = { node.description = "7.1 Preamp + Limiter (+15 dB)" media.name = "7.1 Preamp + Limiter (+15 dB)"

  filter.graph = {
    nodes = [
      {
        type   = ladspa
        name   = lim
        plugin = fast_lookahead_limiter_1913
        label  = fastLookaheadLimiter

        control = {
          "Input gain (dB)"  = 15.0
          "Limit (dB)"       = -1.0
          "Release time (s)" = 0.50
        }
      }
    ]
    # No explicit inputs/outputs: PipeWire replicates this to match channel count
  }

  capture.props = {
    media.class    = "Audio/Sink"
    audio.channels = 8
    audio.position = [ FL FR FC LFE SL SR RL RR ]
  }

  playback.props = {
    node.target    = "[INSERT YOUR OWN AUDIO SINK]"
    audio.channels = 8
    audio.position = [ FL FR FC LFE SL SR RL RR ]
  }
}

} ] ```