1

Let's say I had a mic on a gooseneck on a podium, and the PA was blaring and very loud.

The gooseneck is pretty much bolted to the floor.

There is usually a huge feedback ring around 250-300.

Could this theoretically be caused by a sympathetic vibration from the floor of the stage as well as the neck of the gooseneck?

How would one go about isolating a gooseneck such as a podium mic from the floor or any other surface which might be rumbling?

Thanks in advance for your help.

2

Hi-pass it... Or at least EQ it way down. Assuming the 250-300 Hz range really is the problem.

Can you move the loudspeakers so they're in front of the mic, or angle them at all?

And how hot are you keeping your signal? I know that's probably already something you've considered, as well as proper mic technique of your presenter, but it's good to revisit it.

| improve this answer | |
  • I want it full and loud in the house, at least 85 dB. Low-passing thins it up and makes it sound tinny. The speakers are at least 20 feet forward from the podium position. – Utopia Apr 26 '11 at 23:17
  • After that, I'm out of suggestions. :p I don't deal with podium mics in any live settings. Sorry. – Dave Matney Apr 27 '11 at 1:25
2

Hi You said that the gooseneck was bolted to the floor but didn't state as to whether the mic was permanently fixed to the gooseneck, ie the cable going through the gooseneck into the floor as well. If that is not the case and the mic is removable then there are a number of options. First, to check if the feedback is caused by the attached GN. remove the mic and just hold it gently, this will isolate it from the floor, get someone to jump up and down and see if you still get the same feedback. Second. Make sure that the GN is not bent too much.

There are connectors and adaptors available that are designed to reduce podium noise and rumble. You can get an isolated XLR socket that will connect to the podium or floor that is basically surrounded in soft rubber. You can also get an isolating microphone clip that can help to eliminate stand-transmitted noise.

What microphone are you using?

Hope this helps. I can give you links to that kind of equipment if you need any more help.

| improve this answer | |
  • Awesome. Thank you very much @Si Charles. The mics I'm using are 2 MK41 capsules on a single gooseneck. The neck isn't bent too much - just arcs into a 90 degree angle from the top of the podium. The mic is pretty much solidly on the gooseneck. The colette adapters are screwed to the tip of it. I will definitely try holding the mics and see if that works. You can definitely hear the footsteps transmitted to the mic as well as when someone taps the top of the podium. – Utopia Apr 27 '11 at 16:40
  • I'm seriously thinking about trying to mount a dark grey CMIT 5U on the podium... – Utopia Apr 27 '11 at 16:56
2

What mic are you using?

The feedback is most likely due to the dimensions of the room, which creates a standing wave. What you normally do is use a notch filter, a 31 band graphic equalizer is perfect for this. Then you can cut the offending frequencies until they are just below the level of excitement. Another approach is to switch to a supercardioid mic.

It is unlikely that vibrations from the floor or stage are causing the feedback, I would look at the sound transmitted through air first. If you want to check, just hire a suspension mount for the mic and pop it on a normal stand in the same position as the podium mic. If the feedback goes away then it is definitely the stage.

| improve this answer | |
  • I second that as well! – Si Charles Apr 27 '11 at 7:25
  • Thanks @Iain! 2 MK41s is what I'm using. I've got a DN360 as well as a DN3600 I could use at FOH. I'll bring a shockmount and a stand to test it out - that's genius. Don't know why I didn't try that in the beginning... Maybe because I don't have much time on setups and it didn't cross my mind. – Utopia Apr 27 '11 at 16:42
  • I'm seriously thinking about just mounting a dark grey CMIT5U on the podium... – Utopia Apr 27 '11 at 16:56

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.