I don't play metal, but the Sadowsky 5-24 is among my main axes for the last few years...I can imagine settings that could be on the muddy side, but that's easily fixed, and I'd think the tone of these basses would be ideal for what you describe. Are you using stainless steel rounds? I'd also suggest favoring the bridge pickup by about 10% (I'm assuming you have pickup pan rather than V/V), plucking/picking closer to the bridge, and experimenting with some settings that engage the preamp. I've lately taken to setting the active B and T at 50-60% and backing down the volume, but that is not in a metal setting. And I'm curious about how the bass drum is pitched and equalized. Like Fenders, Sadowskys seem to slot nicely in that "just above the bass drum" band. Is the bass "muddy" relative to other things, or "muddy on its own?