I’ve been dealing with a fairly consistent issue with input stereos “misbehaving” where after firing up the desk and connecting a stereo source to input stereo’d inputs on my GX4816, the right/even channel of the pair will show low or non-existent level. At first I though my stereo XLR cables, sub snake cables, or the same GX input channels were the cause. But I’ve done some troubleshooting where I’ve used different cables, snakes, DIs and different channel pairs on the GX and it still happens. What seems to “wake up” the right channel is to hot pull the connection while signal is going and plugging it back in. It will suddenly start to work. I’m 99% sure at this point it’s not a physical connection issue but possibly a glitch that occurs when the desk is first booted up or there’s a fresh stereo-ing of channels rather than a boot up or show file recall. Has anyone else run into this? It’s driving me a bit crazy.
One thing I forgot to mention is believe this is not just a metering issue, I believe the level of the signal (direct assigned to the L/R bus) is also matching. I’ll need to verify that next time it happens.
The only time I had something like this, I suspected I had a pad on one of the channels before making stereo. It was heat of the moment, so my solution was to make mono, remove pad, make stereo. In hind sight, I wonder if just toggling pad on/off would have gotten both inputs synced up.
I have had a similar issue, which turned out to be an a phantom power issue on one of the channels. It seems that when you configure a stereo pair on the avantis the phantom power doesn’t show the status of the second paired channel. Eg. Is you stereo pair channels 3 & 4, if channel 4 has no phantom, but channel 3 does, you can’t control the phantom to channel 4. To solve this you have to decouple the stereo pair, activate the phantom and remake the stereo. I wonder if your hot plugging technique was enough to jog the phantom. The other thing to watch with stereo pairs is the Pad setting on the mono channels before stereo coupling. I’m pretty sure they can also get out of sync with each other.
Is it always the same physical inputs?
Are the preamps for both stereo channels set the same? You can adjust various preamp settings for each individual source that makes up the stereo channel by going to the routing page and clicking on the individual source’s number at the top of the routing page. So if yours stereo pair was made up of local sources 5 and 6, you can go to the I/O patch page for local inputs and click on the local Input 5 label (at the top) and see the preamp settings for that source. Likewise if you click on the local Input 6 label, it will show pop up with the preamp settings for that source.
It’s possible that the individual sources have different preamps settings (gain, pad, polarity, etc). This won’t be reflected in the stereo channel processing pages, you have to go to the I/O Patch page and check there to be sure.
Interesting, thanks for the insight. This is occurring with different physical and mapped inputs.
Good thing to try, thanks for the tip.
Ok, it happened again today setting up for a Halloween show. Newly stereo’d inputs. Made certain it was not wiring by connecting a mic to a Y cable and splitting it into the pair directly on the GX. Pad was on. Tried toggling the Pad on/off, didn’t help. Turned Pad off, didn’t help. Cranked the input gain way up - problem solved. I forget to verify if the level issue was just metering or actual gain from the channel out the buses. But, I’m 100% convinced this a bug of some kind.
If you map two inputs to a stereo channel, the preamps don’t get reset (nor set to the same values). It could be intentional that the settings are different,if you have two inputs with very different gain settings for whatever reason.
An M/S setting with different mics, a DI box with a pad on one channel activated accidentally, for example.
I’ve never seen that behavior on any other brand of desk, it would be usual. It also wouldn’t make sense if you had an offset between 2 channels when pairing them, and then have it suddenly snap to no offset when grabbing the gain knob. Lastly, I checked both the A&H and other another tutorial on stereo’ing channels, and there’s no mention that any differences in gain or other parameters will stay when applying the change. If you needed parameters to not be matched, you would use the ganging function rather than “stereo’ing” a channel where the assumption is that the device feeding the inputs is a true stereo source and all parameters should match. I’m going with my assessment that this is a bug, not a feature.
Was easy to do on the Digidesign Profile when making two mono channels into a stereo channel. Many times, if I wasn’t paying attention, I had mismatched gains, pads on one but not the other, phantom on one but not the other, and it would carry over into the stereo channel.
With the Profile, it was easy enough to fix in that you just hit the +48v or Pad twice and it would even them out, or crank the gain all the way down and then back to where it was needed.
The SC48 was my primary desk before the Avantis and I’ve never had that happen in over a decade when stereo linking channels. Same software and DSP as Profile so the behavior should be the same.
Only ever happened had I not been paying attention. Though it was also easy to adjust the gain since it would show the discrepancy in the “Right Offset” field, which you could easily right click and reset to 0