Vocal feedback problem[views:2546][posts:9]____________________________________ [Oct 2,2008 4:41pm - ouchdrummer ""] So here's my question. We (useful idiot) have just started using a TC Helicon Voicelive plus rackmount. Which by the way has fantastic effects, and a great interface to edit them through a midi cable and a puter. Now, he's singing with an sm57, through a monster cable into rack, outta rack with balanced monster cables, into a yamaha PA head. Ya know one of the 250watt so-so ones. This PA head is unfortunately going through a marshall guitar cab. (just until we get new speakers, which will be soon) As soon as he started using the voicelive, we got all sorts of feedback with just about any effect on his voice. And due to Maynard using all sorts of megaphone, flange, delay, reverb, and chorus effects, it's just not gonna sound right without em. Now without the voicelive, there is a little feedback, but not much. So obviously it's the voicelive that's causing it. So. How do we fix it? I assume the correct speakers will help alot, but as there was no feedback with the same speakers before the voicelive, i don't think that's the whole problem. Will a different mic help? A low noise one perhaps? Maybe some other rackmount that will cut the extra noise? The voicelive has a gate and compression on it, but the more we try to fuck with that, it seems to almost get worse. Any advice would be greatly appreciated. **I almost remember when i was a kid seeing an EQ rackmount that had lights over the different bandwidths that lit up when there was feedback being caused and you could specifically turn down the exact frequency causing feedback... but as i think about this more, i don't think i have ever seen one since. That was in the first studio i ever went in, so they might not exist anymore, or i could remember it wrong. |
| ____________________________________ [Oct 2,2008 5:10pm - ouchdrummer ""] help.. please? |
| ________________________________ [Oct 2,2008 5:24pm - sxealex ""] the guitar speakers are too sensitive |
| ________________________________________ [Oct 2,2008 5:26pm - live sound guy ""] You need to get real speakers before making any kind of honest judgement. Second - you mention that the feedback is there, albeit much less, without the effects. This tells me that the processor is definitely affecting the amount, but is not the cause. There are many causes of feedback, from cupping the mic (don't do it, i don't care how cool you think it looks) to poor gainstaging to speakers being too close to mics. An SM57 is a fairly standard and low-z mic to begin with, that's not the problem. What kind of board/amp setup are you using? How is the gain staged (input trim/EQ/output volume relationships)? If the board has EQ - which it should - try to turn down the higher frequencies a bit. Also, how is the gain set on the FX machine? Is it outputting a very high or low signal? How is the input trim on the board? IF you have the output of the FX machine set low and make up for it by cranking the input on the board, you'll get more feedback. There are a million causes for feedback and you didn't quite give enough info to diagnose it. Also, using a guitar cab is awful - stop it immediately. You could potentially be damaging the amp or the speakers due to impedance issues as well. |
| ____________________________________ [Oct 2,2008 6:07pm - ouchdrummer ""] Thanks. While i know that we SHOULDN'T be using a guitar cab, we really don't have any other choice right now, and the impedance/wattage matches up. But yes, i totally understand that the cab is a bad.. no terrible idea. As i am not the vocalist, i can not directly remedy that, he is saving for new speakers, and will have them shortly. He never cups the mic, he is a trained opera singer, and has great technique with his voice/knows how to sing properly into a mic. As far as the eq, i actually was aware of what you were saying regarding the (input trim/EQ/output volume relationships) and have gone so far as to turn the highs completely off, turned the output on the processor all the way up/down with the input on the amp all the way up/down..etc.. we tried a but load of combos. Whether or not the voicelive is affecting the feedback or not, it's much much worse with it, while there is near to none without it. I guess i would like to know how you would setup the amps eq, the voicelive's output, the amps trim. Because i am fairly pragmatic, and have tried a multitude of combinations, without avail. And if there is any sort of processor/whatever that will find the eq causing feedback and cut it. |
| ________________________________________ [Oct 2,2008 6:13pm - live sound guy ""] What board and amp are you using? Is it a powered mixer? "Proper" gain staging says to set everything to unity (or "0"). I would set the FX machine to that first, this will give you the best, cleanest output possible. Second, turn the channel fader on the board off and set the input trim so that it, too, is at "0" or unity or whatever - it should have a "PFL" button to monitor this (pre fade level). Then simply set the channel volume fader to the appropriate level. Now, for the EQ - do you have anything turned up? You mention turning down the highs, but what are the other settings? A good rule of thumb is never to turn EQ up - to boost a certain frequency, turn others down. You'll get a much cleaner sound this way. Does your FX machine have any compression on it? Try playing with that if so - setting your threshold higher might help. How many layers of FX are you using? Adding more will invariable add noise, and when you're already in a "sub-optimal" setup, this could make the situation worse. |
| ____________________________________ [Oct 2,2008 6:24pm - ouchdrummer ""] No nothing is turned up. Initially we had everything set in the middle, i was saying that we tried going up, and down with almost every eq bandwidth. It had a 9band parametric eq, and a low/mid/high for each channel. As i mentioned, the voicelive has compression, and a gate, i just know that when i turned on the compression, it got worse. The manual for the thing also states that you should be careful when using compression as it is easier to have feedback with it. On some of the parts there are 4-5 effects, depending on what maynard does in the real song. |
| ________________________________________ [Oct 2,2008 6:30pm - live sound guy ""] Yeah - compression can add feedback if not set carefully. I would suggest removing it altogether in your case. Also - that 9 band EQ is not parametric, it's likely graphic, even if it might be labelled "parametric". Like I said - first just try it when you get real PA speakers, it's possible that the guitar cab is too sensitive (as someone mentioned). Next - try taking FX off one at a time. There could be one you've set wrong or is weird or whatever. |
| ____________________________________ [Oct 2,2008 6:33pm - ouchdrummer ""] thanks man. |
| ________________________________________ [Oct 2,2008 6:35pm - live sound guy ""] No problem. Good luck! |