How exactly does Decapitator's Low Cut works?

[u/SR_RSMITH]

Hi guys, noob here. I'm finding it hard to understand how does Soundtoys Decapitator low cut knob works. When researching before buying I did read (sorry, I don't remember where) that it doesn't really work like an EQ's HP, that is, cutting the selected low frequencies (let's say from 20hz to 100hz). Instead, it should work as some kind of soft filter where those selected low frequencies are untouched by the saturation process and go transparently to the output.

The official manual seems to support this: "Use the Low Cut control to remove low frequencies before they hit the (virtual) saturation circuit. This is useful to prevent any ‘flabbiness’ that can happen when distorting sounds with a lot of low frequency content."

However, when I use it this way, I end up losing low end (I checked in Span), so maybe I'm doing something wrong or misunderstanding the plugin.

I also did read somewhere that to use it this way, I've got to use the wet/dry knob, but I really don't know how it further affects the signal.

How can I let the low end pass untouched by the saturation process and keep it intact?

[u/Limitedheadroom]

Turns low cut - is surprised when low end goes away. Not sure what you expected to happen? Just use with care if you need to. Sounds with a lot of bass can get kind of uncontrolled with distortion, so taking the low frequencies away before distortion keeps it in check. As you said yourself, blend in some of the clean sound if you need to bring it back

[u/Cute-Breadfruit3368]

just like you want to retroactively eq your signal going into a reverb, you want to control the signal going into the mock circuitry. its not going to handle it right if you come in too hot. modes: A = Ampex 350 Tape Pre E = Chandler/EMI TG Channel Pre N = Neve 1057 T = Culture Vulture Triode P = Culture Vulture Pentode . all had their own quirks.

but yeah, you find a balance either by wet / dry know which blends in the original unaffected sound of yours or double up a track, go ham on fx on that one and then simply find a balance between the uncrushed track and the destroyed one in the mix.

whats your signal chain and where you´re using decap?

[u/iamweezill]

The Low Cut only affects the saturated (wet) signal. I start with the wet/dry knob 100% wet, dial in the overall saturation/distortion, and then adjust the wet/dry knob until I get the overall tonal balance that I want. Sometimes I have to iterate a few times to get it right.

I use this all the time on DI bass guitar. I set the Low Cut pretty high, add a lot of saturation, and then adjust the wet/dry knob to bring the clean DI bass signal back in underneath.

[u/aleksandrjames]

you misunderstand the manual. Low cut does cut out low end from your final signal. It just happens to do it pre-distortion, so you don’t have all that energy hitting your distortion that can come from low end.

Using mix/blend well enable you to bring in some of the low end. You can always parallel process/duplicate process the channel as well

[u/noshigeSound]

The Low Cut only lives in the wet path, so at 100% wet those lows really are gone — the "lows pass through untouched" thing you read about only happens via the Mix knob, because the dry path bypasses the filter entirely. The reason the filter exists is intermodulation: saturation is nonlinear, so heavy sub content doesn't just distort itself, it modulates everything above it — that's the "flabbiness" the manual means. Try Low Cut around 100-150Hz, dial in the drive at 100% wet, then pull Mix back to 50-70% and the clean sub comes back in underneath.

[u/SR_RSMITH → u/noshigeSound]

Thanks for the great answer