Advice needed. Compression live?

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Commodore
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Advice needed. Compression live?

Post by Commodore » Mon Jun 11, 2007 4:46 am

Hi Everyone,

I perform live using a laptop. My mic is plugged into the firewire interface.

Should I put compression on my vocals (using plug-in's)?
If yes... whats a good setting or do I need to "feel" things out at soundcheck?
Does compression increase feedback? (I usually do not have any... Shure PGX system)

I already add EQ because I had to and I have the pad switch ON on the interface.

Any other advice would be greatly appreciated!
-Commodore

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Roboburger
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Post by Roboburger » Fri Jun 15, 2007 11:02 am

compression does not increase feedback, it's the make-up gain after the compression that raises the noise floor and feedback potential. if you are using the compression to limit (high ratios, high threshold, quick attack and release) and not as a gain stage, you should be basically okay. Y'see, when a signal gets compressed, it's level is lowered. When you apply makeup gain to get it back to the proper level, you are also amplifying the noise floor, which is where the feedback beastie lives.

As a club FOH guy as my career, I will state that the majority of people who effect their vocals do it incorrectly- what sounds right on the laptop headphones might not exactly transfer to the Club PA. If you are alone with your laptop, you can 'get away' with more than someone playing with a band.

A few months back, I had a guy want to run his vox through a cheap early digitech guitar multi-effect that was noisy and so squashed and gained the mic that it caused feedback problems, but also- every other sound bled onto the mic and caused a weird Phasey thing that sucked. The guy did his vocals in his bedroom studio through it and got great results monitoring through headphones, and couldn't understand that with his SM58 being six feet from two guitar rigs, an SVT, a drum set, and his own loud floor wedges, not to mention the backside of the suspended FOH speakers- he couldn't get the same sound.

For their last tour opening for Kings Of Leon, I convinced Jordan of Snowden to give the PA a split/combo of Dry mic and Effects unit on two XLRs that would be combined at FOH, that way the Monitor amounts could be adjusted for optimum ratio there, and the FOH guy could also mix to taste depending on the various factors there. Also, in between songs, the effect fader could be dropped so you don't sound silly when chatting up the crowd. I'll see them tonight and find out how it went.
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kayagum
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Post by kayagum » Fri Jun 15, 2007 11:16 am

And explain to me why you want compression on your live vocals?

Between the speakers, the space and the compressors/limiters that the PA setup may already have, it's highly unlikely you need compression on your side, especially on vocals. Roboburger is spot on.

Using a compressor as an effect on guitars is a completely different issue- for sustain, squash or intentional feedback...

Application first, gear second....

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Roboburger
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Post by Roboburger » Sun Jun 17, 2007 11:13 am

Oh, there are valid reasons why someone would want to compress their vocal themselves- I wasn't outright poo-poo-ing the idea. I was just attempting to make him ready for the possibility that the cool sounds you can get into your headphones or small room speakers at home might not translate to a larger venue. However, an artist is free to do whatever he/she wants in my club.

I get cool sounds sending to a delay/verb before the signal is compressed- that way, the effect gets bigger as the guy sings/screams loud- but then the original vocal is squashed and kept level by a compressor later on a subgroup. The crowd perceives a giant increase in vocal level because the effect thickens up relative to the vocal level, but my speakers stay safe.

On Friday night, all three bands had onstage vocal processing. the first two did it wrong and had probs hearing their monitors. the third- Snowden- gave me the split signals that I mentioned above, and everything went great.
Audio Engineer Euphemism for going number two: "Rollin' off the Low End."

runrunrun
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Post by runrunrun » Sun Jun 17, 2007 2:35 pm

im planning on setting up a little rack to run as a live vocal channel (pm1000 pre > LXP1 verb > pro VLA). I like the sound of the VLA and its better than the comps in place I will be playing.

having never done live sound, how much compression can I get away with before starting to cause problems? is limiting a better idea? it will be on fairly small stages with a moderate amount of stage volume.

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Roboburger
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Post by Roboburger » Thu Jun 21, 2007 12:15 pm

yes, limiting is a better idea. higher threshold and ratio. try setting the threshold at zero, and the ratio at 4:1 of 6:1. that way, normal talking will be below the threshold, singing will just tickle the zero threshold, but a good hard shout reduces by about 6-12 dB.

Also- consider the parallel angle. go from the PM1000 channel -signal splitter. run one side to the verb, and have a direct box from that output to give to the soundguy, the other side of the split signal goes to the comp and then to the soundguy on a different channel. (If your racked PM1000 has two outputs, you won't need the splitter)

Now you can use the second, dry channel for the monitors (trickle in a bit of wet, too), and have the FOH guy mix the two for FOH. if you know what you are doing, you can somehow kill the wet signal between songs so when you address the crowd, it's not a glob of reverby goo.

why do this? well, a lot of smaller clubs have crap monitors, and the wet signal will be tricky for them to deal with reverb/feedback issues. So splitting them gives more control to the situation.
Audio Engineer Euphemism for going number two: "Rollin' off the Low End."

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