spinynorman Posted August 27, 2008 Share Posted August 27, 2008 We seem to spend a lot of time at gigs trying to get a decent volume out of the vocals without feedback. It usually comes right in the end, but always feels like trial and error, despite all the stuff I've read about how to do it with EQ. So I was wondering if a feedback suppressor like the Behringer Destroyer, or DBX AFS224 would be a good purchase? We're using a Yamaha EMX512SC which has quite limited EQ, so that could be why it feels difficult. Quote Link to comment Share on other sites More sharing options...
BOD2 Posted August 27, 2008 Share Posted August 27, 2008 They are OK as a last resort. They usually have several parametric notch filters (these allow the centre frequency, filter width, and attenuation to be selected). The filters can be fixed or set "roving". The usual mode of operation is to switch the Feedback Destroyer on then bring up the PA volume. When feedback starts the filters will be activated and will cut the troublesome frequencies. Then you bring the PA back down a notch and everything should be ok, in theory. This is the same principle used by experienced sound engineers manually with a graphic EQ and is called "ringing out". You then also keep one or two of the filters on auto roving mode to catch any feedback that occurs later if mics are moved etc. But remember - they work by cutting frequencies, so your sound will suffer from the lost frequencies to some extent. It's much better to take more care over mic placement and basic EQ first. Make sure any monitors are immediately behind a mic - not to the side. Keep mics away from a solid back wall where reflections will come off the wall and into the mic - if this happens, moving the mic 6 inches forward may cure the problem. Always try and identify which mic is causing the problem - is somebody turning up towards the end of the gig ane messing up your carefully created soundcheck levels ? Quote Link to comment Share on other sites More sharing options...
thinman Posted August 27, 2008 Share Posted August 27, 2008 [quote name='spinynorman' post='271408' date='Aug 27 2008, 11:10 PM']We seem to spend a lot of time at gigs trying to get a decent volume out of the vocals without feedback. It usually comes right in the end, but always feels like trial and error, despite all the stuff I've read about how to do it with EQ. So I was wondering if a feedback suppressor like the Behringer Destroyer, or DBX AFS224 would be a good purchase? We're using a Yamaha EMX512SC which has quite limited EQ, so that could be why it feels difficult.[/quote] We had similar problems with foldback feedback so I bought a Behringer SHARC. It doesn't really seem to work that well but maybe it's not set up right. I'm going to get a 31-band graphic now - anything less or just a couple of parametric bands is not usually adequate as far as I know as the resonant frequencies in each environment will vary and normal EQs are too broad to take them down without adversely affecting the sound. Quote Link to comment Share on other sites More sharing options...
coasterbass Posted August 28, 2008 Share Posted August 28, 2008 Depends if you are doubling up as soundman whilst playing. If you have a soundguy, or just someone capable who hangs around with you whilst you play, then the 31-band EQ approach is best. But, if you are trying to play whilst run the PA then the feedback destroyers work really well as they can move faster than you can. I used the Behringer Ultracurve for a long time and found it worked very well (as it contains the twin-31 band EQ as well). Looking at other options, I'd also say that upgrading your cabs and mics will help a great deal too. Nothing causes feedback like a pair of PA speakers being driven (too) hard, and quality mics help isolate unwanted noises too. If you are mic'ing the drums then a Gate is essential and will make the job much easier and prevent much of the stage feedback. Quote Link to comment Share on other sites More sharing options...
Fraktal Posted August 28, 2008 Share Posted August 28, 2008 (edited) I have had very good experiences with the Sabine FBX series. Never tried any other brands, though. Anyway the best option to control feedback is in-ear monitoring. Some vocalists hate them but in my experience thats because they use crappy in-ear headphones. Its a very good idea to try several headphones with a in-ear monitoring system, the difference in frequency response between different brands and models is huge, and sometimes vocalists prefer the headphones with more mid frequencies boost, even though they arent the best quality ones, because those help them hear the voice much better. You also save a lot of weight and space to carry when gigging, and you also clear the onstage noise and volume levels, something mixing engineers would kill for! Edited August 28, 2008 by Fraktal Quote Link to comment Share on other sites More sharing options...
spinynorman Posted August 28, 2008 Author Share Posted August 28, 2008 [quote name='coasterbass' post='271628' date='Aug 28 2008, 11:12 AM']Depends if you are doubling up as soundman whilst playing. If you have a soundguy, or just someone capable who hangs around with you whilst you play, then the 31-band EQ approach is best. But, if you are trying to play whilst run the PA then the feedback destroyers work really well as they can move faster than you can. I used the Behringer Ultracurve for a long time and found it worked very well (as it contains the twin-31 band EQ as well). Looking at other options, I'd also say that upgrading your cabs and mics will help a great deal too. Nothing causes feedback like a pair of PA speakers being driven (too) hard, and quality mics help isolate unwanted noises too. If you are mic'ing the drums then a Gate is essential and will make the job much easier and prevent much of the stage feedback.[/quote] We're only putting vocals through the PA which makes it easier, speakers are new Mackie C300z, so I'd be gutted if they were a problem. I wish I'd realised about the 31 band eq before we bought the Yamaha, but there's no sound guy, and often not much space, so the feedback destroyer sounds like an option worth considering. Quote Link to comment Share on other sites More sharing options...
Count Bassy Posted September 4, 2008 Share Posted September 4, 2008 [quote name='BOD2' post='271420' date='Aug 27 2008, 11:27 PM']But remember - they work by cutting frequencies, so your sound will suffer from the lost frequencies to some extent.[/quote] Yes, but they are cutting frequencies at which the room tends to resonate anyway, so you could argue that they actually give you a more balanced sound and that without it those resonant frequecies would come over excessively loud. A bigger problem is that if you 'ring out' when you're setting up, ie with the room empty, the response will be totally different once the room is full of sweaty bodies. Quote Link to comment Share on other sites More sharing options...
joegarcia Posted September 5, 2008 Share Posted September 5, 2008 Common problem is people using too much input gain on vocal channels. Try backing it off a fair bit and putting the faders up. This always works for me along with EQ. Are you using compression on the vocals with excessive make-up gain? If so, maybe try turning that down too. Quote Link to comment Share on other sites More sharing options...
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