ringing out a system

Posted: Tue Sep 18, 2007 12:10 am

what's the "proper" way to ring out a system after setting up a room?

is it best to go microphone-by-microphone? or floor monitor-by-floor monitor?

generally i'll just turn up gain on each mic until the brink of squealing and adjust the EQ on my mixer.

i'll be getting a few EQs for my floor monitors soon. so once those are set up, i assume that i would turn up the gain on each mic until the squealing and then adjust the EQ on the monitor system (instead of the mixer), right?

how does everyone else do it?

-dave

Posted: Tue Sep 18, 2007 5:48 am

I no longer ring out systems. Not since I started using DSP, a laptop and SMAART. No need for it. It can damage drivers.

Any system will ring at some point at any frequency with enough boost. If I was not able to use SMAART, I guess that I would have to ring it...maybe.

Posted: Tue Sep 18, 2007 6:39 am

By "Ringing out" do you mean feedback tuning? If this is the case, you probably should start mic-by-mic but get each mic sounding good. Then return to square one and bring up "ALL" mics to tune the system with master EQ. Feedback is the sum-total of inputs, not just one mic. You may have 1 more of a problem than another but the TOTAL level is what causes feedback.

Posted: Wed Sep 19, 2007 5:25 pm

sheet, your answer was totally useless. Razz

i suppose that ringing out monitors would be similar to ringing out FOH right? except with more mics it gets tricky. i hate small stages with cement walls. grrr!

Posted: Wed Sep 19, 2007 11:47 pm

I have mixed on all sorts of stages, from little oblong brickyards, to 1500 seat venues, and every sound guy I have ever seen (who doesn't use smaart....) rings out the system exactly the way you are doing it. Monitor by monitor, mic by mic.

All I do is take a 58, set the gain settings on your desk to unity, and slowly bring it up in the monitor wedge. You have the most control over feedback if you have a 1/3 octave graphic eq on each monitor mix, and I always try to eliminate the bad frequencies on the graph before cutting frequencies on your desk. As long as you have your wedge controlled on the graph, you can eq each channel on your desk just as you would if you were mixing at FOH. Keep in mind, if you don't have a dedicated Monitor and FOH console, your channel eqs will most likely effect what is going to your wedge as well.
If all of your wedges are the same, you can match the graph on each mix and you have a really good starting point for all of your mixes onstage. Each singer will be different and different mics have different frequency responses, so the graphs may change in different situations.......
Now, only thing left is learning your frequencies like the back of your hand, so you can cut those bastards the second they get away from ya.
Once you have rung out your wedges a few times you will get to know the 31 band graphic eq very well. And your room!!

Your on the right track. Soon enough when someone says "Turn it up!", they will be asking, "Can you turn it back down a bit?"......and it won't be cause of the feedback!

Posted: Thu Sep 20, 2007 1:04 am

"Ringing out" ANY system is very dangerous to the drivers AND to the ears. While you may not have the tools at your disposal that Sheet spoke of, you can do it with a little more caution. Since you are dealing with hard reflections from a cement wall environment (bar? basement?), you have to start off with EQ settings that are sympathetic with that. Look at your settings on the mixer (including any 'Air' controls it may have) and use common sense here. Make sure that NOTHING is boosted, that any and all High Pass (same as Low Cut) filters are engaged. I would also preset the 'Mid-Sweep" (frequency) control at between 800-1.2KHz to start off with; you gotta be able to dial that region in quickly to reduce any "mid-sqawks" that might rear their ugly heads. Now go to your graphics.Roll off the lows below 100Hz.; that's all mud-crud, anyway, at least in your environment. Then set the bands above 2KHz. so that there is a gentle, downward slope, levelling out at -6dB @8KHz and higher. Got that? OK, now:
Mute all the channels, pull the faders, zero-out the monitor sends.
Get the stage area cleared out except for ONE person to test the mics. I know that different singers are going to have different levels, but one asshole onstage is enough, you don't need a whole band in your way Laughing

Set you house and monitor masters to their appropriate "nominal" settings.
Pick the "money channel"-that's the main vocalist, the performer that needs to be the loudest in the mix. Un-mute that channel. Have your test person (aka, guinea pig) walk up to the mic (on its stand) and...CLAP their hands right up front of the mic. Have them use a regular, repetitive rhythm ( I use "one-onethousand, two onethousand..."). Clapping lets you clearly hear the onset of any feedback without being masked by yacking.
Now bring up the channel fader SLOWLY, listening carefully for any feedback nodes (resonance points). Use your mid-sweep with a slight mid-dip gain setting (-3 to -6 dB) to minimize this. Got it? NOW have the tester talk into the mic, to get a proper level reading. As he/she/it does so, go to your graphics, and carefully re-introduce the upper bands you'd previously attenuated, one band at a time, starting at the lowest point (2K) and working upward from there. DON'T BOOST!! Once again, you're listening for onset...
Keeping that mic channel open in the house, do the same thing with its monitor send. Some people will kill the house to test the monitors, only to get burned when they discover that pulling them both up can yield more feedback, due to phase interactions between the house and wedgies(intended, that's what they can do to you!). Anyway,mute that mic and proceed with the next vocal mic, then mute it when you're done. ONCE you're finished with all of the vocal mics that need to be addressed, you can start off un-muting each and listening carefully to any tonal changes/nodes as you build up 'live' mics in the system. Make your adjustments-this includes re-positioning any mics/speakers as needed.
Then you can play with the drum and geetar mics, they're childs' play.
BTW, before I get any flack for this, I learned this procedure from a guy named Lothar Krauss back in the 70s when he worked for a dude named Hartley. Lothar was Peavey's designer of the infamous Mk IV boards (and other assorted gear) and hired me to beta test his designs at blues festivals throughout the South. This procedure has served me well over the years when RTA's weren't onhand.In fact, even then, it's come in handy. Just using what God gave us all to use-our ears and hands! Good luck.

Posted: Sun Nov 25, 2007 5:40 pm

I'm in Jamaica and just starting to do live, doing small clubs - open air ...

I'd like to start with building my own box, a good beginner's set up... any advice.

Posted: Mon Nov 26, 2007 6:12 pm

cathode_ray wrote:

By "Ringing out" do you mean feedback tuning? If this is the case, you probably should start mic-by-mic but get each mic sounding good. Then return to square one and bring up "ALL" mics to tune the system with master EQ. Feedback is the sum-total of inputs, not just one mic. You may have 1 more of a problem than another but the TOTAL level is what causes feedback.

At some point, you could cut every frequency and have nothing left.

There are two reasons for feedback. One is acoustic. The other is electronic. The first task at hand is to tune the room, by placing the proper speakers in the proper spot. That will get you half way there. The next thing is to known what your speaker's polar plots look like. All speakers lobe somewhere. Horizontal arrays, vertical arrays and line arrays all lobe as a system. Knowing what frequencies are coming out of the back of your cabs and where will help you place the band and mics.

There are some speaker systems, like those piece of crap JBL HLAs that have nearly just as much sound coming from the back as the front, for example. There are some great sub companies that have managed to drop the levels behind their cabinets, which is hard to do.

So, I place the PA where it needs to be, then I place the stage, then I place the band, then I place the mics. Some of you don't have that luxury, so you have to hack at the EQ. You might also try time aligning the mains to the backline/drums in smaller venues. This can help you out in EQ land sometimes, and it also tightens up the sound.

When I twaek monitors, yes, I get on the mic and do my thing. I name the frequencies that need to be cut, the house or monitor guy does it. and I am done. BUT, that is only after I move the wedges first, or change mics to match the environment. In some instances, I may not want a Beta87 that picks up offstage farts in the dressing room. So we might go with a SM86. Let the mic suit the job and use EQ as a last resort.

I have seen guys use a 57 to tweak the mains. I think that is silly. The 57 is not as sensitive and far from flat. Use a good measurement mic.

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