Matt F Posted March 22, 2009 Share Posted March 22, 2009 Hi, For a school production, we are using 5 hanging microphones to pickup the stage. There is a combination of 2 Rode NTG-1s and 3 Sennheiser cardioid microphones (sorry, hired, I don't know the models - stage electrics hire these as "sutiable for hanging" though). The microphones are not that high, and it seems obvious to me that we should have good pickup on then before feedback, however, we are getting next to no pickup before feedback. To set the microphones up, I set the channel to 0, and then slowly creep up on the gain until feedback, I then try to alter the sweep frequency (each channel has a 4 band eq (I think)), in order to get more gain. However, there is a limit to how far the gain will go as obviously, they feedback. Despite this, the safe level is not picking up anything. I really do not know what to do here to get more pickup. If you need any more information in order to help me, please let me know! Thanks in advance,Matt Link to comment Share on other sites More sharing options...
Pyramid Posted March 22, 2009 Share Posted March 22, 2009 Hi Matt Most important things to look at are: the direction the mics are pointing in (relative to the FOH speakers, or reflecting surfaces), make sure that the mics are pointing as well as possible to the sources of sound (actors mouths) and are not pointing too high or low. the position and angle of FOH speakers. Are the speakers too near the hanging mics? Generally the further they are from the stage more level before feedback is achievable. After the above two have been checked ring out, preferably using a parametric or graphic eq to sort the system/room out and then use the channel eq for individual mics. HTH Andy Link to comment Share on other sites More sharing options...
Matt F Posted March 22, 2009 Author Share Posted March 22, 2009 Hi Matt Most important things to look at are: the direction the mics are pointing in (relative to the FOH speakers, or reflecting surfaces), make sure that the mics are pointing as well as possible to the sources of sound (actors mouths) and are not pointing too high or low. the position and angle of FOH speakers. Are the speakers too near the hanging mics? Generally the further they are from the stage more level before feedback is achievable. After the above two have been checked ring out, preferably using a parametric or graphic eq to sort the system/room out and then use the channel eq for individual mics. HTH Andy The mics are all pointing towards the actors and are pointing in totally oposite direction to the FOH speakers. The speakers are a good 10-20ft away too. Could you elaborate on your final point please? Thanks Link to comment Share on other sites More sharing options...
Rob_Beech Posted March 22, 2009 Share Posted March 22, 2009 The channel eq should really be used individually. a parametric or graphic eq really ought to be inserted over a group or pair of groups for these mics to give overall control. Your regular hire company should be able to help you out here. Link to comment Share on other sites More sharing options...
Matt F Posted March 22, 2009 Author Share Posted March 22, 2009 The channel eq should really be used individually. a parametric or graphic eq really ought to be inserted over a group or pair of groups for these mics to give overall control. Your regular hire company should be able to help you out here.So, for example, using sub group and then run a graphical EQ through the sub insert? Link to comment Share on other sites More sharing options...
Rob_Beech Posted March 22, 2009 Share Posted March 22, 2009 Yes, this is pretty much how most people would achieve this where possible. Link to comment Share on other sites More sharing options...
Matt F Posted March 22, 2009 Author Share Posted March 22, 2009 Yes, this is pretty much how most people would achieve this where possible. Ok thank you. Do you know of any guides that could help me with using the graphical EQ to stop feedback? Also, could you suggest a decent graphical EQ for under £150? Link to comment Share on other sites More sharing options...
Pyramid Posted March 22, 2009 Share Posted March 22, 2009 Ringing out with the mixer channel eq is very crude, specifically control of the frequency notch (Q) altered is none existant. All you can generally control with a mixer eq section is the frequency acted on and the degree of cut or boost.When using a parametric eq you can alter, typically 5 frequencies and have total control over Q width and so can keep it as narrow as possible. This is desirable because there are usually a few resonant frequencies in each room but if too much is removed from the frequency spectrum the sound can start to lose it's integrity.A graphic eq is better than a channel eq, not because the Q is adjustable - it isn't, but you can adjust any one of a number of frequencies, with a mixing desk you're limited to 2-4. Andy Link to comment Share on other sites More sharing options...
johndenim Posted March 22, 2009 Share Posted March 22, 2009 Quite a handy piece of info here.What's the desk? Link to comment Share on other sites More sharing options...
Matt F Posted March 22, 2009 Author Share Posted March 22, 2009 Quite a handy piece of info here.What's the desk?Thanks for the info, I shall read it now. Desk is a Soundcraft Spirit FX16. Link to comment Share on other sites More sharing options...
Rob_Beech Posted March 22, 2009 Share Posted March 22, 2009 I'd look at hiring from your hire company you get the mics from. An accurate EQ with a nice sound can set you back 5 times your budget yet be £10 per day or less to hire. Link to comment Share on other sites More sharing options...
paulears Posted March 22, 2009 Share Posted March 22, 2009 As you've not done this before it does strike me that it is quite possible that what you've got IS the best it is going to be. Cardioids do have rather odd pickup patterns at the sides, with strange lobes that can easily head towards the speakers, but overhead mics are rather a difficult thing to make work for the majority of productions, simply because projection is often poor, and when people speak, they tend to project downwards, not upwards. If stage height isn't too great then theres often a nasty reflection from the floor, which is about the same distance from the mouth, as an overhead mic is above it. PCCs or PZMs on the stage edge, always (for me) perform better - but with distant miking of any kind, it relies on the people making more noise than the unwanted noises all around them. When you walk near to the speakers when the mics are near to their maximum, what can you hear? There must be something, or the mics wouldn't feed back. If - as I hope isn't right - you are trying to use a distant mic technque on quiet performers, then ..... to quote Private Frazer, you're doomed! Link to comment Share on other sites More sharing options...
Alex222 Posted March 22, 2009 Share Posted March 22, 2009 Hi. You cold try getting them at floor height, it could be some weird deflection of the sound around the walls/roof that might be causing it? Have had that one before in places where you wouldn't expect feedback to be caused by that. Could dry cutting below 100 on the eq. From the point of what you are trying to pick up, remember rubbish (quiet dialog) in rubbish out... Also one really obvious point, you have got phantom power on ? or an internal 1.5v battery (AA)(just thought I would mention as nobody else has (well not that I saw) ) Alex. Link to comment Share on other sites More sharing options...
bruce Posted March 22, 2009 Share Posted March 22, 2009 Also one really obvious point, you have got phantom power on ? or an internal 1.5v battery (AA)(just thought I would mention as nobody else has (well not that I saw) ) I would suspect the reason that nobody has mentioned it so far is because it's a complete red herring.... If the mic power was not on, how would we get feedback? Link to comment Share on other sites More sharing options...
Sound Man Posted March 22, 2009 Share Posted March 22, 2009 Whats the make and model of your FOH speakers? David Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.