# Low end (boomy sound) & resonance

**URL:** <https://unity.neuraldsp.com/t/low-end-boomy-sound-resonance/20951>\
**Category:** Quad Cortex\
**Created:** [January 24, 2026, 8:19pm UTC](https://unity.neuraldsp.com/t/low-end-boomy-sound-resonance/20951 "2026-01-24T20:19:01Z")\
**Posts on this page:** 1\
**Showing post:** 19

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**Author:** ![Alex\_K](https://avatars.discourse-cdn.com/v4/letter/a/5fc32e/32.png) [@Alex\_K](https://unity.neuraldsp.com/u/Alex_K)\
**Post date:** [January 26, 2026, 10:45pm UTC](https://unity.neuraldsp.com/t/low-end-boomy-sound-resonance/20951/19 "2026-01-26T22:45:38Z")

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I’m sure I haven’t run QC output into an amp input 🙂 QC output was going to the return of the amplifier, that’s exactly my setup (see as of 5:26):

[![](https://us1.discourse-cdn.com/flex020/uploads/neuraldsp/original/2X/d/d85044c5cc86d864582ec8c69cfdffe945e99857.jpeg "What is the 4 Cable Method & How Do You Use It? - Everyone with a Multi FX Pedal NEEDS To Try This!") ](https://www.youtube.com/watch?v=U--x5w_Mqfg&t=322s)

and that’s exactly how described here [Quad Cortex with Real Amp](https://unity.neuraldsp.com/t/quad-cortex-with-real-amp/6507)

Are you saying that I had to do it differently, meaning setting an output of the whole chain to Send ?

e.g. this is how all presents look like:

 ![chain_output_3](https://us1.discourse-cdn.com/flex020/uploads/neuraldsp/original/2X/f/f9a84169342206d65cea6afbf6dc8fbc06869a53.jpeg)

Although I call it 4 cable method (which I will tweak later to fully benefit from it) chain doesn’t use it fully, but just an input and output.

But instead I can try this:

 ![chain_ouput_send](https://us1.discourse-cdn.com/flex020/uploads/neuraldsp/original/2X/6/69ea82d7a0f7a53f5e537e647a5dc53f078dd7b9.jpeg)

Tried, it works, but didn’t notice any sound difference (late night, will try also tomorrow with more gain). As you can see there is a bypass flag on the CAB - I presume it is bypassed.

I just realized a lot of people in community do it as you said:

[https://unity.neuraldsp.com/t/quad-cortex-with-real-amp/6507/9](https://unity.neuraldsp.com/t/quad-cortex-with-real-amp/6507/9)

Shall I also try TRS cables ? Does it make any difference ?

Regarding Master volume control, one of the great things about the Engl Fireball 25 is that even with the preamp bypassed, you still retain Master volume control - unlike many Marshalls, where bypassing the preamp removes the master volume entirely and blasts the full 100W straight into you face.

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