SAC comp/limit

[SCF Sound Guy]

Getting the hang of SAC little by little.

We still have a couple of channels that clip every now and then.
I have tried a couple of times to use the channel comp but the channel still clips.
Meter set to pre-fade, thres = -15, att= .040, rel= .100
Even if I set the ratio to infinity, the channel registers a clip.

Any ideas?

[Craig Allen]

Attack isn't fast enough, and never really can be to catch absolutely everything. If it's only on occasion and you can't hear it, I wouldn't worry about it.

[gdougherty]

Unless the channel meter is on src and you have no attenuation, input channel clips are from the converter and not anything you can prevent in SAC.
I have noted that even with a lowered threshold and recording with tape-it, a .01ms attack still lets an initial peak through. The pulse is so short though as to be imperceptible. Only a look ahead limiter can act in time to naturally catch the peak and we don't get that live.

[Bob L]

Most likely, your chan meter is set to SRC... check it... if so... which is where you usually want it in SAC, then the clip is letting you know the signal coming in is too hot... you can use the attenuator control to back off the signal, or you should lower the trim level on the mic pre itself.

Bob L

[SCF Sound Guy]

Bob,

The meters are set to "input/return-pre-fdr".
My impression is that the meters should reflect any processing, right?

Is there no way to prevent clips registered in SAC?

On our Presonus Octopre Dynamics we can use the built in comps to prevent clips.
Is this the best way to do it?
Is there anyway to do the same with SACs comps?

My goal is to get a hot signal but prevent overloads.

[Alex]

What Bob was saying, set your tap source to SRC to know if the signal is clipping at the pre, you have it at "input/return-pre-fdr the comp is working if you set to pst-fdr you would not see a clip but the pre would still be cliping.

The clip your seeing is at the source. If your using an RME card, open the mixer and you will see the clip there also. Setup your pre to its max input, just touching the clip point then back down the gain to give alittle headroom.

Alex

[Naturally Digital]

Setup your pre to its max input, just touching the clip point then back down the gain to give alittle headroom.That's right. Then make the gain back up digitally, in SAC, after the channel comp.

[AntonZ]

My goal is to get a hot signal but prevent overloads.

If your preamps are not particularly noisy and you are using this for live audio (as opposed to recording at the signal/noise limits of your gear), then my suggestion is to back down the preamp gain a bit and use SAC to pull up levels if you need it. If you set the mixer to process audio at 24 bits internally, then there is plenty of room for good signal quality in a SAC rig without riding your preamps right up to the clipping point.

[airickess]

Don't be afraid to run your preamps a little lower and then push the fader past 0.

[Bob L]

I recommend keeping faders near zero... use the attenuator control at the top of the SAC chan modules to add gain.

Bob L

[airickess]

I recommend keeping faders near zero... use the attenuator control at the top of the SAC chan modules to add gain.

Bob L
Why? What's the difference in SAC between pushing the fader past zero and using the attenuator control? There should be no difference.

[sstillwell]

Why? What's the difference in SAC between pushing the fader past zero and using the attenuator control? There should be no difference.

Because you can run out of fader while mixing. Better to get everything close to a nominal mix with faders zeroed and have more room to move.

From a Signal/Noise standpoint, there shouldn't be much if any reason on a digital console.

My $0.02 worth...Bob's may differ.

Scott

[airickess]

Because you can run out of fader while mixing. Better to get everything close to a nominal mix with faders zeroed and have more room to move.

From a Signal/Noise standpoint, there shouldn't be much if any reason on a digital console.

My $0.02 worth...Bob's may differ.

ScottI understand that, but the fader in SAC does go up to +20 just like the attenuator. Also, if you need +20db of gain on a channel by ramping up the attenuator or the fader then you have a problem.
I'm not questioning basic set up of gain structure. I'm questioning why Bob suggests the attenuator rather than the fader.
All I had advised was that the OP not be afraid push the fader above 0. I do this all the time when I am mixing a particular show or presentation where there are multiple people using the same microphone. I'm going to ride the fader in those situations, not the attenuator.

[gdougherty]

I prefer having the signal to where my fader rides at 0 or a touch below simply because I can get finer control in that range. Personally, I'd rather see only 10db of gain above 0 with slightly finer control than the 20db we have now.
Usually I don't need to push it past 10db anyway and I only do that with the arrow keys because of how finicky control with a mouse can get in that range.

[jlklein]

I'm not questioning basic set up of gain structure. I'm questioning why Bob suggests the attenuator rather than the fader.
All I had advised was that the OP not be afraid push the fader above 0. I do this all the time when I am mixing a particular show or presentation where there are multiple people using the same microphone. I'm going to ride the fader in those situations, not the attenuator.

I don't think Bob meant never to go above zero, but rather that if you're finding yourself frequently going significantly above zero, add some gain via the attenuator. Standard practice is to try to run your faders in the +/-5 dB or so range as that's where it's easiest to control based on the typical logarithmic fader characteristics. It's also easier to get all your fingers on multiple faders if they're close in level setting :)

Of course, if you have multiple persons using one mic you may find yourself all over the fader and you go where you have to go.

Jeff

[Bob L]

You can also clip vst plugins on channels if the gain is too strong coming into the chan strip... by using the attenuators to put the signal back into perspective levels, that is less likely to happen.

Bob L

[RBIngraham]

With multiple people on mics I always give each person their own channel strip anyway. Even back in the analog days we would split the signal to two or more inputs using insert jacks. With digital desks, ala SAC it's even easier and makes even more sense. This allows you not only to adjust gains per individual but also EQ, comp settings, etc...

[airickess]

With multiple people on mics I always give each person their own channel strip anyway. Even back in the analog days we would split the signal to two or more inputs using insert jacks. With digital desks, ala SAC it's even easier and makes even more sense. This allows you not only to adjust gains per individual but also EQ, comp settings, etc...
Of course you are speaking in terms of a theatrical production that has rehearsal time and lead-time to make mic plots, and that makes perfect sense in those situations.
My shows where there are multiple people at a single mic are one-offs where folks use a single podium mic or a single wireless handheld. No rehearsals, no mic plots, and sometimes no show run-downs and certainly no scripts.