Clipping mains - need solution; vocal clarity help also needed

Mr. Pickles · #1 09-02-2010, 08:53 PM

I know it sucks, but I'm mixing my bar band from the stage... We don't have the option of a sound person at this point.

Here's the skinny -
Rock cover band
Bar gigs - 50-200 people
Players don't use excessive volume/wattage

Rig:
Mackie 1604 VLZ Pro
Ashly dual 31 band eq
Presonus Bluemax / FMR RNC (total of four channels of dual mono compression)
Lexicon MPX 550 for vocal/drum fx
Crown K2 amp

Monitors - peavey wedge (drummer)
Mackie SRM450 (lead vox)

Mains:
2 Mackie Thumps on poles (they sound really good!)

what's miced?:
4 vocal channels; kick/snare; bass di; lead and rhythm guitars

The eq is on the monitors, as the mains never seem to feedback. However, even with proper level setting on each input channel, and no clipping at mixer output, the overload lights flash intermittently on the mains. How can I remedy this. Budget is limited at this point. Would you suggest putting limiters on the main out inserts? If so, what kind? Would compression help on the main outs?

Also, the thing that I've found most difficult is getting the lead vox enough signal out of the monitor without feeding back. Things that work in the studio, like eq boost around 4Hz, only makes more feedback. The only signal in the vocal monitor is vocals, by the way. The drummer gets a full mix and it never feeds back, even though he has a vocal mic and the snare miced right next to his wedge.

I've been fooling around with both compressors on vocals, guitars, and drums.

I'm brand new to live sound, so any help is welcome. I've done a fair bit of searching and reading in both the live sound forum (here and at TGP), FWIW.

KingRazor · #2 09-02-2010, 10:26 PM

At my church if we want to keep the mains from clipping we have to run them about as low as they can go. Our soundboard is HOT (it's a really nice board, but the signal it produces is too much for our speakers if we run them any higher than bare minimum).

I've been doing live sound for less than 2 years, so you'll probably want to seek more professional advice. But I'd try dialing down the mains or applying limiters.

Not sure how to fix the monitor problem. :\

otis_thick · #3 09-02-2010, 10:40 PM

You could try reversing the polarity of your monitor's speaker wires this reverses the the polarity that the mics see...

Relpace one end of the speaker cable with a (5 way) bannana plug then make or buy a bannana jack to 1/4in plug....then you can flip flop the connecter polarity as needed....but you must do all of the monitors at the same or you will end up with null spots around the stage....when the polarity is reversed you can almost put the microphone up against the monitor at full volume and not get feed back!

Wes Whitmore · #4 09-03-2010, 06:46 AM

Most people reverse polarity of Mics, not speakers...

Just guessing here, but isn't that a very hot monitor? It it intended to be a main, and turning it on it's side it turning the horn 90 degrees off axis and the mics are picking it up. You didn't mention what you were using for vocal mics, but maybe that monitor is pointing right at one of them, or the drum mics causing the feedback. Try muting the drums when it feeds back and see if it goes away, then you will know the source of the problem.

Put at least one channel of that dual 31 band EQ on the mains and use it to EQ the room. You need to have some control of those active speakers in different environments. Put the other one on one of the vocalist monitor to help fight some of that feedback.

If the input of those powered mains are being overdriven, then turn down the mixer main output until it stops clipping. If the mains have a sensitivity adjustment for the input, you might need to adjust it so it reaches full power at a higher mixer output. Can you send the mains a high pass signal from that board? Take out as much bottom end that the cab can't produce as possible, either by crossover, or dumping channels on the 31 band EQ. Think about saving up for a sub to handle the kick and bass guitar as the next step. Take the kick out of the mains now though. That's a huge task for those mains to try to reproduce.

Wes

Mr. Pickles · #5 09-03-2010, 08:05 AM

Thanks, Wes. I'll try that. (even though the kick sounds great through the mains

)

Yes, the vocal monitor is really hot, but the vocal mics are all SM58s and Senn 835s, so they have decent off axis rejection.

Keep those suggestions coming.

Zooberwerx · #6 09-03-2010, 08:16 AM

I'll assume you've sent your mic channel input trims properly.

*Where are your mains volume sliders set?

*Where are the Crown's attenuators set?

Sidenote: 400 hz and 4 khz are notorious for inducing feedback. I like the idea of running one Ashly EQ channel for the mains, the other for the monitors. Your FOH will be mono but that's not a bad thing.

Riis

WayneP · #7 09-03-2010, 09:04 AM

If you can see that the mains clip indicator is sync’d with the kick drum, then I’d do what Wes sez and take it out. An alternative might be a compressor for the kick.

Re the vocals, make sure there is no compression on the vocal feed to the monitor.

Quote:

Originally Posted by Zooberwerx

Your FOH will be mono but that's not a bad thing.

FOH should be mono.

Regards,
Wayne A. Pflughaupt

Pedulla Club #45
Administrator, Tobias Club
My Rig: Stage and FOH Friendly

Mr. Pickles · #8 09-03-2010, 09:57 AM

The input trims are all set properly. I did put some compression on the drums which helped a bit. The main output slider is only about halfway up and the input on the powered mains is at unity. The crown is only powering the drummer's monitor (only using ch. 1 - ch. 2 is turned all the way down) and the attenuator is three clicks back from full on.

I am running the mains in stereo (the fx are the only thing running stereo though, everything else is panned center).

So, to recap:

run mains in mono (that way I can use one of the 31 band eq channels for the mains and one for the mons)
cut out kick from mains until we get a sub
no compression in vox monitors - why is this anyway?

Anything else?

WayneP · #9 09-03-2010, 11:11 AM

Quote:

•run mains in mono (that way I can use one of the 31 band eq channels for the mains and one for the mons)

Right. You can change the Crown amp to parallel mode. That way a mono input will send the same signal to both channels/speakers

Quote:

•no compression in vox monitors - why is this anyway?

It’s the vocalists specifically you don’t want compression on. Other things can be compressed before being sent to the vocal monitor.

The reason is that singers are used to hearing themselves get louder in the monitor when they sing louder. If that doesn’t happen, they’ll sing all the harder and end up taxing their voices.

Regarding your situation in particular, if the vocals are compressed, the absence of those dynamics might be the reason the singer is having a hard time hearing him/herself. Aside from that, the logical solution is to simply pull everything else in the vocal monitor down so the singer can hear him/herself better.

Regards,
Wayne A. Pflughaupt

Pedulla Club #45
Administrator, Tobias Club
My Rig: Stage and FOH Friendly

JackANSI · #10 09-03-2010, 11:17 AM

Quote:

Originally Posted by WayneP

Re the vocals, make sure there is no compression on the vocal feed to the monitor.

+1

Not only will your vocalist not be hearing themselves correctly (with their dynamics intact), compression will help start feedback (when the gain reduction goes away) when the singer is quiet. If that is the case and making a clean send to the vocal monitor works, you're also applying too high a ratio overall on the vocalist (and too much makeup gain).

otis_thick · #11 09-03-2010, 11:24 AM

Quote:

Originally Posted by Wes Whitmore

Most people reverse polarity of Mics, not speakers...
Wes

True, but his mixer does not have that feature!

Zooberwerx · #12 09-03-2010, 12:44 PM

Quote:

Originally Posted by Mr. Pickles

The input trims are all set properly. I did put some compression on the drums which helped a bit. The main output slider is only about halfway up and the input on the powered mains is at unity. The crown is only powering the drummer's monitor (only using ch. 1 - ch. 2 is turned all the way down) and the attenuator is three clicks back from full on.

I am running the mains in stereo (the fx are the only thing running stereo though, everything else is panned center).

So, to recap:

run mains in mono (that way I can use one of the 31 band eq channels for the mains and one for the mons)
cut out kick from mains until we get a sub
no compression in vox monitors - why is this anyway?

Anything else?

If you're clipping the mains with the sliders at 50% and the mixer is not clipping, you've got a signal mismatch goin' on. Ideally, you should be able to advance your sliders to -0- with a nice near-linear response and no clipping on either component. First thing I would do is attenuate the input level control on the Mackies well below unity and reassess. From what I read, the Mackies are strange agents...you can plug a mic directly into the enclosure, boost the input level, and go to town. Neat!

Riis

GregShadoan · #13 09-04-2010, 03:50 AM

I'm sorry, you lost me with:
Mackie Thumps on poles
What the hell is that?

Zooberwerx · #14 09-04-2010, 06:49 AM

Quote:

Originally Posted by GregShadoan

I'm sorry, you lost me with:
Mackie Thumps on poles
What the hell is that?

This is what I'm goin' by:

http://www.mackie.com/products/thump/

Powered two-way mains with a 15". They have defeatable 4 band EQ and can be used as a stand-alone PA.

Riis

Mr. Pickles · #15 09-04-2010, 12:23 PM

When I wrote "Poles", I meant speaker stands, although poles could also be "sticks", but in that case they'd be mounted on the subwoofer.

GregShadoan · #16 09-04-2010, 01:51 PM

The OL light intermittently is probably ok. If its on all the time, that would be bad. It says in the manual that they will flash when nearing OL. Basically you are hitting the ceiling on them.
Here is the quote from the manual:
"The OL (overload) indicator lights when the
amplifiers in the TH-15A are near the clipping point. It
is okay if the OL indicator blinks occasionally, because
this means that the transient peaks are just reaching
the maximum output of the amplifiers and you are
getting the most from your TH-15As."

Yamaha had a similar setup. The OL lights would flash 3db below clip.

walterw · #17 09-04-2010, 05:36 PM

take all of the bass and most of the kick out of those speakers.

in fact, they should have little besides vocals in them. use the stage amps to make up the difference.

once you get subs, you can take the low frequencies out of the tops, which will make them stronger at the mids and highs so you can run the whole band into them.

big +1 on keeping the vocals in the monitors uncompressed.

this means not inserting compressors on vocal channels (which squashes their aux outs), but rather inserting comp on a group or even left or right main out, hard panning all the vocals into that group or that side and hard panning everything else to the other side and using the mono out for the main signal.

+1 as well to using one side of the EQ for mono mains and the other side for monitors; taking the low end out of the monitors will also make them louder for vocals.

Mr. Pickles · #18 09-05-2010, 07:37 AM

Taking the compressor out of the vocal channel inserts made a huge difference. As was said, it was easier for the lead vox to control his dynamics as he could hear the difference in sound in relation to his mic position.

The clipping light is intermittent, which is ok per the manual (thanks for pointing that passage out to me- I missed it).

I'll take out the kick until I can get a sub. But, will the addition of a sub releive the tops so that they don't reach clipping? Will they have more headroom because they're not working as hard to reproduce the low freqs?

Zooberwerx · #19 09-05-2010, 08:00 AM

Quote:

Originally Posted by Mr. Pickles

I'll take out the kick until I can get a sub. But, will the addition of a sub releive the tops so that they don't reach clipping? Will they have more headroom because they're not working as hard to reproduce the low freqs?

That's my understanding and experience. I threw in a xover, power amp, and a couple of 18" subs...made a world of difference. You'll still need to re-establish headroom, though, especially if you're still seeing anything more than intermittent clipping well below unity / -0- on your master faders.

Riis

walterw · #20 09-05-2010, 07:58 PM

Quote:

Originally Posted by Mr. Pickles

I'll take out the kick until I can get a sub. But, will the addition of a sub releive the tops so that they don't reach clipping? Will they have more headroom because they're not working as hard to reproduce the low freqs?

that's exactly it.

lows take way more energy to reproduce than mids or highs (that's why a 30 watt guitar amp can be louder than a 300 watt bass amp).

giving the tops only say, 100Hz and above will make them much happier.