Pan law option?

[billlorentzen]

Pan law is a term used in audio for an intentional drop in volume when a pan pot is in the middle position. Usually it's 3dB of reduction, so that the center doesn't sound louder than L or R.

 

When I use a split and pan between them, there is a louder hot spot in the center of the pedal sweep, which is both unnatural sounding and prevents a graceful, gradual change from one sound to another.

 

I put a suggestion on ideascale if you want to support the addition of a pan law feature.

http://line6.ideascale.com/a/dtd/Pan-Law-Option-for-Splits/819820-23508?submitted=1

[ricksteruk]

Sounds like a good idea. Voted :)

[jeremyn]

Excellent option. Hard to believe they didn't already do that.

[Digital_Igloo]

Excellent option. Hard to believe they didn't already do that.

I'm pretty sure we do it automatically; it was in the definition for sure. IIRC, it's 3dB; will have to check with Ben tomorrow. Maybe it was dropped at one point and no one told me?

[billlorentzen]

I'm pretty sure we do it automatically; it was in the definition for sure. IIRC, it's 3dB; will have to check with Ben tomorrow. Maybe it was dropped at one point and no one told me?

I tested for it by starting with an empty patch and making a split with an EQ (normaled) and panning across with a pedal. It definitely was significantly louder in the center position; I didn't measure, but it sounded like about 3 dB.

 

I agree, it seems like it should be a standard feature. Thanks for checking on it. Because of the way I use splits, it's quite important to me.

[kronda]

I'm pretty sure we do it automatically; it was in the definition for sure. IIRC, it's 3dB; will have to check with Ben tomorrow. Maybe it was dropped at one point and no one told me?

 

 

I tested for it by starting with an empty patch and making a split with an EQ (normaled) and panning across with a pedal. It definitely was significantly louder in the center position; I didn't measure, but it sounded like about 3 dB.

 

I agree, it seems like it should be a standard feature. Thanks for checking on it. Because of the way I use splits, it's quite important to me.

 

This is perhaps compatible: Combining left and right channels in the center raises volume by 6dB (double...) and one way of compensating for that is -6dB in the center (DAWs have that option usually). But even though that's technically correct it usually sounds like too much gain loss and -3dB compensation is now usually the default (at least in Cubase I think) as a compromise. So if Helix implements -3dB compensation it would still sound 3dB louder in the center when panning L -> C -> R.

 

So it does seem all "correct" to me. But I may be wrong. And it would definitely be nice to have an option to switch the panning law but please make it local for each split/merge block, not global...

[njglover]

Seems related to my issue with A/B splits. Those are set by default to reduce volume by 3 dB, so if I'm using it as a way to switch between two separate paths, I have to boost the merge block by 3 dB to compensate. I would much rather the merge block say -3 dB in its default state so that it's more obvious that it is reducing the volume rather than me having to guess that that is what it is doing.

[stephane_dupont]

Seems related to my issue with A/B splits. Those are set by default to reduce volume by 3 dB, so if I'm using it as a way to switch between two separate paths, I have to boost the merge block by 3 dB to compensate. I would much rather the merge block say -3 dB in its default state so that it's more obvious that it is reducing the volume rather than me having to guess that that is what it is doing.

 

Made a post and a support ticket for that. Made me lose an hour of testing to figure it out. At least it should be in the manual!

[Digital_Igloo]

Just confirmed with Ben; Helix does indeed implement a 3dB pan law.

 

When I use a split and pan between them, there is a louder hot spot in the center of the pedal sweep, which is both unnatural sounding and prevents a graceful, gradual change from one sound to another.

 

How exactly are you panning between two split paths? Perhaps there's something in the block usage and routing.

[billlorentzen]

Just confirmed with Ben; Helix does indeed implement a 3dB pan law.

 

 

 

How exactly are you panning between two split paths? Perhaps there's something in the block usage and routing.

In use, I assign an exp pedal to a split, one side with a distortion on it, the other without, and merging in front of the amp. The amp is also controlled: as the pedal increases, I juice up the drive and sometimes pull back the master. The distortion pedal is optional - in other words, I use it when I want more dirt. A lot of the time, just pushing the amp is the desired sound, and in that case, I'm still panning across the split, but it's not adding a distortion pedal, just passing signal. I noticed that the middle position was as loud or louder than the full forward, which seemed wrong (and is also undesirable in this usage).

 

I tested it by starting with an empty patch and making a split with an EQ (normaled) and panning across with a pedal. It definitely was significantly louder in the center position; I didn't measure, but it sounded like it could be about 3 dB.

[jeremyn]

Choosing the pan law is an interesting conundrum. It heavily depends on the number and level relationship between the signals that are being combined. 3dB is an industry standard middle ground that is not perfect for every combination of mixed sources, but is better than 6dB or 0dB that might work well for equal level signals that are perfectly in phase, or two signals with wildly different levels.

 

The general rule for panning is that the signals are uncorrelated, and that they are of approximately equivalent power levels.

[billlorentzen]

I think it may be important to explain pan law a bit to understand how it impacts helix users. In a perfect world, a mono signal should be at maximum when panned hard left or right, and should be reduced by half (-6dB) on both the left and right sides when panned center. In a typical record mixing scenario, a level bump in the middle position is useful because room acoustics usually cause the outside positions to seem louder. Apparently the difference has a lot to do with how well the room is tuned. Disney studio determined a 3dB drop was optimum - BBC chose a 4.5 drop (perhaps their rooms were tuned better.) In live Helix usage, most of the time our signals are summed to mono when we output to amplification. In recording, frankly, none of this really matters - if you record a stereo signal, you can balance it however you wish in the mix process.

 

Here is some more data on pan law, if you're interested: http://prorec.com/2013/05/the-pan-law-of-the-land/

 

As I see it there are two important uses for panning in Helix.

 

One is to split a signal to two different paths for things like two amps, two speakers or two discreet effects chains. In this case, the pan law is not really critical, as you can adjust the final balance at various points to get the desired levels.

 

The other usage is to be able to actively change the panning across two paths as you play. In this case, the pan law is critical. If you get a level bump in the middle (which -3 gives), the sweep across is unnatural and sounds bad when summed to mono, as it usually is. I generally use panning to go from one sound to another with an exp ped. I need to be able to acces the full changing range of the sounds as they change from one to the other. A level bump in the center makes this option far less workable.

 

My conclusion is there should either be adjustable pan laws for splits, or the -6 pan law should be implemented universally. I hope L6 gives some attention to this!