Levels and different kinds of splits

[lcuani]

Well. i searched in previous topics and even though this subject was talked i couldn't find a solution to a specific doubt.

What would be the exact difference in Y split and A/B split? I know u can control the level that goes to each channel with A/B. But  isnt this the same  as changing the levels of each path in the merge block (Y split case)?

 Or , in the A/B case, routing more to channel A for example, would result in less INPUT level in channel B? in this case, gain sensitive blocks would suffer (for example in a 70-30 split, no side would get the normal input.. actually neither in the 50-50 split it would get, cause both sides would recieve only half of the input making it odd to use)

 

My intention is to split the signal in two amps. So it seens the Y split is more suitable, right? But i saw people complaining the y split reduces both inputs by 3db in order to keep the volume the same when the paths merges. But wouldnt this also change the input gain for the amps? or the level compensation  happens in the merge block?  but in both cases, in a scenario where i want to route each amp to a different output, both signal would be reduced by 3 db even though i didnt merge them?

 

Obs: I could make this tests myself but i actually dont have a helix yet and i am considering my possible use cases and if they can be acomplished. Thank you for all the help and sorry for bad english.

[zolko60]

Good questions!
Actually when I make either Y or A/B split I hear my guitar louder, so there is no gain compensation.
Split Y is even between A/B paths with respect to gain but you can adjust pan balance, so maybe there is some paning law compensation?
Swapping A/B Paths works better with A/B Split automation than Merge Mixer automation because you can set level to minus infinity vs. -60dB in merge mixer what leaves some bleed.

Exploring Helix is so exciting!

[Thurston9]

Your English is very good and you stated the question very clearly.   This is an important and complicated topic.  Hopefully someone will clear it up in this thread.  Thanks for posting! 

[zolko60]

This is not complicated at all, but the only owner manual we have is for kids. Maybe after 3 years of product lifespan it is time for some adult version  ;)

[lcuani]

21 hours ago, zolko60 said:

Good questions!
Actually when I make either Y or A/B split I hear my guitar louder, so there is no gain compensation.
Split Y is even between A/B paths with respect to gain but you can adjust pan balance, so maybe there is some paning law compensation?
Swapping A/B Paths works better with A/B Split automation than Merge Mixer automation because you can set level to minus infinity vs. -60dB in merge mixer what leaves some bleed.

Exploring Helix is so exciting!

Thank you for the help. So it seems, in a A/B scenario if you split to two amps and you make an uneven split,  one amp will be reached with lower gain than intended

[zolko60]

I guess "uneven" means "intended gain difference".

[lcuani]

4 minutes ago, zolko60 said:

I guess "uneven" means "intended gain difference".

Well... kinda makes sense. if i want to change raw volume output i should just change parameters in the merge block instead of the split. Ty

[Meiannatee]

I haven't tested this so correct me if I'm wrong:

 

1) Split levels

Levels at split = levels going into split path.

I.e. if amp is in split path, higher split levels will drive the amp harder.

 

With no panning/balance changes, each path = same as before split.

 

1a) Split>Y

Default - duplicates signal to 2 paths (no volume drop).

Pan to either side = reduce volume on one channel (L or R) while maintaining volume on the other channel.

 

1b) Split>A/B

Duplicates signal to 2 paths.

Turn "balance" control off center = reduce volume of one path (both L&R channels) while maintaining volume on the other path.

 

2) Merge

Sums path A and B.

I.e. After merge = (A_left + B_left) and (A_right + B_right).

 

Merge level is post-split blocks.

I.e. if amp is in path A/B, merge level does not affect amp gain.

 

Sum of 2 sources of equal volume = +3dB.

E.g. If u split without changing pan or balance, don't change levels on both paths, and don't change levels/pan on merge, then level after merge vs. before split is +3dB.

 

Each channel of each path is an individual sound source.

E.g. Hard-pan both paths to L = +3dB L and -inf dB R (or -60, doesn't matter)

E.g. Hard-pan path A to R, path B to L = same post-merge level (if L&R channels are the same in both paths)

[lcuani]

22 minutes ago, Meiannatee said:

I haven't tested this so correct me if I'm wrong:

 

1) Split levels

Levels at split = levels going into split path.

I.e. if amp is in split path, higher split levels will drive the amp harder.

 

With no panning/balance changes, each path = same as before split.

 

1a) Split>Y

Default - duplicates signal to 2 paths (no volume drop).

Pan to either side = reduce volume on one channel (L or R) while maintaining volume on the other channel.

 

1b) Split>A/B

Duplicates signal to 2 paths.

Turn "balance" control off center = reduce volume of one path (both L&R channels) while maintaining volume on the other path.

 

2) Merge

Sums path A and B.

I.e. After merge = (A_left + B_left) and (A_right + B_right).

 

Merge level is post-split blocks.

I.e. if amp is in path A/B, merge level does not affect amp gain.

 

Sum of 2 sources of equal volume = +3dB.

E.g. If u split without changing pan or balance, don't change levels on both paths, and don't change levels/pan on merge, then level after merge vs. before split is +3dB.

 

Each channel of each path is an individual sound source.

E.g. Hard-pan both paths to L = +3dB L and -inf dB R (or -60, doesn't matter)

E.g. Hard-pan path A to R, path B to L = same post-merge level (if L&R channels are the same in both paths)

TY, a lot of information here. I thought helix had a system to compensate this 3 db level gain removing 3 db from each path. BUt seens the behaviior is standard

[lcuani]

Still in the split subject. I see that in the boss gt-1000 you can split path and then split the result of the split (i dont know if what i am saying translates what i want to say)... like nested splits.. it would be useful to have delay, reverb and other effect and none feed into each other. From what i see this isn't possible in the heliz. Am i right?

[Meiannatee]

On 12/17/2018 at 8:49 PM, lcuani said:

TY, a lot of information here. I thought helix had a system to compensate this 3 db level gain removing 3 db from each path. BUt seens the behaviior is standard

Sorry for the late reply. Just my opinion here: there are a bunch of cases where gain compensation is not desirable.

E.g. when setting up path A with clean amp, path B with dirty amp, and toggling them for gapless switching.

E.g. when path B is for 100% wet, path A dry, and then using the exp pedal to blend in as much wetness as desired.

 

In both examples, you would want consistent levels for each path by itself (except the 100% wet path).

On 12/18/2018 at 2:11 AM, lcuani said:

Still in the split subject. I see that in the boss gt-1000 you can split path and then split the result of the split (i dont know if what i am saying translates what i want to say)... like nested splits.. it would be useful to have delay, reverb and other effect and none feed into each other. From what i see this isn't possible in the heliz. Am i right?

There may be some workarounds using the FX send and return.

Another way (that is quite DSP limiting) is setting BOTH inputs - top and bottom chain - to guitar. Now you need to put an amp+cab block on both signal chains, and can't share anything between chains, but u get 4 paths.

 

Thankfully, we seldom need to split to 4 paths. With 2 paths, you can have 2 effects that are independent, plus one "bonus" dry path by using the Mix control available in most FX blocks.

 

Also, personal opinion again, delay into reverb sounds cool and natural. If they repeats muddy up the dry sound, using a darker delay or one with low-pass filter control will usually solve that.

[lcuani]

44 minutes ago, Meiannatee said:

Sorry for the late reply. Just my opinion here: there are a bunch of cases where gain compensation is not desirable.

E.g. when setting up path A with clean amp, path B with dirty amp, and toggling them for gapless switching.

E.g. when path B is for 100% wet, path A dry, and then using the exp pedal to blend in as much wetness as desired.

 

In both examples, you would want consistent levels for each path by itself (except the 100% wet path).

There may be some workarounds using the FX send and return.

Another way (that is quite DSP limiting) is setting BOTH inputs - top and bottom chain - to guitar. Now you need to put an amp+cab block on both signal chains, and can't share anything between chains, but u get 4 paths.

 

Thankfully, we seldom need to split to 4 paths. With 2 paths, you can have 2 effects that are independent, plus one "bonus" dry path by using the Mix control available in most FX blocks.

 

Also, personal opinion again, delay into reverb sounds cool and natural. If they repeats muddy up the dry sound, using a darker delay or one with low-pass filter control will usually solve that.

Yes. No level compensation seens the right thing to do. Especially if the level compensation happened in the split block.. it would make signal reach amp with less gain than intended.

And yes. I guess you are right about hardly using 4 splits. THe most standard effects to run in parallel are delay and reverb and this is easily acomplished. Its just that seens you cant make delay, reverb and chorus in parallel with no effect feeding into each other wich is easily acomplished with the gt 1000 nested splits... but its a very specific use case. I bet that even in boss gt 1000 few people are using this nested splits capability.

 

[njglover]

This may or may not be helpful, but in terms of the use case, a Y split is generally used when you want both paths to be heard at the same time whereas an A/B split is used when you want to hear one or the other but not both. So for a Y split, you would typically use this in your scenario where you have one signal that you want to split to two amps. As mentioned earlier, an A/B split would be if you want to switch from one amp to another, though you could also use it to send the lows direct and the mids/highs to a separate path with fuzz on it as you might do with bass. You could also use it as a Y split if you really wanted to. I have typically used these where I have a clean amp on one path and a dirty on the other and want to toggle between them, but I have also used it in the bass fuzz example. I also used it once to make a doubled guitar effect - in one setting, only one path was used, but when I hit the switch, that path pans left and the other path, panned right, is toggled in. In this case, I would also set both paths to -3 dB on the merge so that I don't get a volume increase.

[perapera]

you may find this helpful:

cheers
Lorenzo

[lcuani]

1 hour ago, perapera said:

you may find this helpful:

cheers
Lorenzo

VERY helpful. SO if i understood correctly, if i use the A/B split to send the signal from an amp block to  2 differnt ccab blocks..so, in theory it would add 3 db to the signal ("2) when you send a signal to a speaker and then send the same identical signal also to another identical speaker you get +3dB (acoustic power sum")

In this case, the pan law attenuation would make perfect sense, right? 3 db reduction in a scenario where i would have 3 db boost... right?

 

Because i am using this method and really feel like, changing the route parameter in the a/b split block changes the overall volume when it shouldnt since the pan law attenuation would attenuate in the middle and not in hte sides...

 

Did i get it wrong?

 

Thank You!!

[perapera]

Yes, I think you got it all wrong, sorry :)

 

You should read it again...

 

I wrote that the attenuation or the boost is happening at the merge block mixer not at the split

 

I wrote that the a/b split "route to" parameter is not very well suited to mix between two different amps (or cabs) on the two paths, but just to switch between them

 

and the acoustic power sum thing applies to... well acoustics, so we're talking real hardware speakers not the virtual speaker cabinets inside of helix

 

[lcuani]

25 minutes ago, perapera said:

Yes, I think you got it all wrong, sorry :)

 

You should read it again...

 

I wrote that the attenuation or the boost is happening at the merge block mixer not at the split

 

I wrote that the a/b split "route to" parameter is not very well suited to mix between two different amps (or cabs) on the two paths, but just to switch between them

 

and the acoustic power sum thing applies to... well acoustics, so we're talking real hardware speakers not the virtual speaker cabinets inside of helix

 

Yes i got it that it happens in the merge., but i dont think that would matter at all in this subject since any db boost or attenuation happening in the split would end up being compensated by the attenuation/boost in the merge block. (since in this case we are not talking about preamps or dirt box that change its tone based on the input gain)..

 

But either way " and the acoustic power sum thing applies to... well acoustics, so we're talking real hardware speakers not the virtual speaker cabinets inside of helix" may explain why the volume still changes... 

I will read it again when i get home to see if there's anything i have missed. But i think the main issue is already resolved ... I'd better create snapshots with different blends of the cabs and try to match the volumes instead of using the expression to control the route parameter of the A/B split

 

It's way more laborious but at least i wont keep stuck in a method that will mislead me due to volume differences.

Thank You!!!

[perapera]

21 hours ago, lcuani said:

Because i am using this method and really feel like, changing the route parameter in the a/b split block changes the overall volume when it shouldnt since the pan law attenuation would attenuate in the middle and not in hte sides...

 

the a/b "route to" parameter does not have a pan law

it changes the volume because it's not a crossfader but a balance so it gives you both paths at full volume at the center position and attenuates one of the paths when you move it

 

so it's a good idea to use snapshots, the best controls to mix two cabs, would be merge mixer faders (problem: they only go down to -60dB) or the cabs or IR's levels or a gain block in each path

 

anyway I think a new "split crossfader" block or better a "merge crossfader" parameter! would be a good addon for a new firmware