Splits and volume levels

[Simbosan]

1) add a gain block at 0 db so it does nothing

2) Drag it down to split path

3) Huge volume boost

 

If you check the merge block it has a 3db boost on top.

 

4) Set the boost to 0db

5) Set both sides of the merge to -3db

 

Sound about equal. Cool, but what about the main volume.  Maybe I can just knock that down 6db

 

Nope, it's quieter!

 

I guess there's two questions,

 

a) why would it default to a +3db boost on top of the natural boost from doubling?

b) What boost would be the same as -3 on both channels?

 

It's a real little gotcha, easy to overload blocks after a split!

 

S

[Simbosan]

Had a cunning plan, just add a 3 tone synth to get a consistent volume.  TLDR: when adding split merge, set the main level of the merge block to -3db

 

Here's what I did

1) Add 3 tone, default settings. Gives an steady output of -17.9 Db RMS
2) Reduced level of 3 tone block to -3db just to sanity check and we get -20.9 Db RMS.  Ok that works, 3db reducation as expected. Leave it there, so -20.9 is the target.
3) Add a split and a merge block (note that the merge has a +3db default) = -14.9. So yeah that's 6db increase with the default +3db
4) set the merge block to -3db, a total of 6db reduction and we're back to -20 Db RMS.

 

So there you go, answered my own question.  When adding a split, just set the level to -3db which makes sense as 3db is a doubling of volume

 

Why they set a default boost I dunno, I reckon they forgot a minus sign!

 

[bbehrens]

This explains why, even though I cut the split by -3.0 dB, I still get problems with Unity gain. Nice observation. Like on the OG Helix, I can use this to my advantage instead of using gain blocks for volume builds in my presets. I just have to be careful of where I put them and what blocks come before and after them as some blocks are additive (such as Reverb and Delay. Still, it CAN be useful.

[PaulTBaker]

I didn't fully understand it, but there was a very good discussion on this a long time ago on this forum.  It would be worth searching for.

[theElevators]

That's expected and normal, as it mirrors the physical behavior.  Combine 2 signals and you get louder signal.  I discovered this on the Helix when I added a delay in parallel by accident.  Then when I removed it, the preset's level changed.  I wound up keeping a delay in parallel as it's easier to manage in the end, and all of my presets have that delay, even if it's not used, for consistency in terms of the level.  

[Simbosan]

On 1/31/2026 at 7:27 AM, theElevators said:

That's expected and normal, as it mirrors the physical behavior.  Combine 2 signals and you get louder signal.  I discovered this on the Helix when I added a delay in parallel by accident.  Then when I removed it, the preset's level changed.  I wound up keeping a delay in parallel as it's easier to manage in the end, and all of my presets have that delay, even if it's not used, for consistency in terms of the level.  

 I did not expect Line6 to add default +3db boost, is my point. That way you get a 6db boost every split/merge unless you remember to edit the level on each one. It's just small gotcha that got me

[theElevators]

That's why it's wise to keep your presets nearly identical, minus a few tweaks, extra blocks that you turn on/off.  On the Helix, it doesn't matter if you have unused blocks btw, the sound does not suffer, and there's no extra lag with unused blocks. 

 

If you redo your signal chain from scratch, then there will be volume / tone discrepancies.  Sometimes you won't realize that they are different.  Create a "template" preset, which is your virtual "rig", and modify it for individual presets: copy/paste/tweak.  That's the best way to use a modeller if you're a touring musician.  Otherwise, just use one preset, if you can manage.

 

Once I learned this workflow, I go through all my presets one after another to make sure they are all sounding correct and matched in volume.

 

I've also once had this weird bug on the Helix, where one preset wound up getting louder, even though the blocks were all identical.  I wound up redoing it from scratch, and it started sounding like my other presets.  Just something to watch out for.  

 

In summary, there are so many factors that can create a difference in your sound, that it's best to just keep everything the same as much as possible.  My tried-and-true approach that I've used for 6 years on the Helix.