PA and monitor setup.....

FarleyUK

Hi all,

We've had our new PA, speakers and monitor for a fair while now, and we keep getting a strange 'boom' that's audible when the singer talks during breaks. It also sounds like it's about to start feeding back, but the lights on the powered mixer don't show anything....

Does anyone have the optimal way to set all this up?

We have:

Yamaha EMX512SC powered mixer - http://uk.yamaha.com/en/products/proaudio/mixers/powered-mixers/emx_box_type/emx512sc/?

mode=model#tab=product_lineup

2 x Peavey Messenger Pro 15 speakers - http://www.gear4music.com/PA-DJ-and-Lighting/Peavey-Messenger-Pro-15-MKII-PA-Speaker-4-Ohm-Single/BGZ

I run the monitor out on the front of the powered mixer into a separate Pulse 200w mixer amp (http://www.amazon.co.uk/gp/product/B0118JOK9I?psc=1&redirect=true&ref_=oh_aui_search_detailpage), and from there, I run a speaker cable to the Phonic S710 (I think) speaker we use as a monitor.

It should also be noted that we have the Yamaha mixer set to output L&R, and NOT Main and Monitor - we use the monitor out on the front to feed the Pulse amp, as mentioned above.

Oh, and all the speakers are in front of our mics.

Any help or tips would be appreciated!

ESBlonde

The cause of the boom is a resonant frequency or one that is excessive in the speakers and or extra sensitive in the microphone resulting in a peak response verging on feedback.

The ideal on a PA is to start with a very flat response and then tailor it from there. Some microphones have different pick up characteristics so omni is equal pick up from all sides, cardioid is heart shaped to the front of the microphone and hyper-cardioid is a tight heart shape (but with a small lobe to the rear).
Not all microphones suit all voices and one reason the likes of Shure, Beyer, AKG etc sell to the pros is because they are quality and reliable.

Placing the monitors in the correct position in relation to the microphone type is very important. Not having a mix of microphone types on a single monitor mix will help. Also trim the low end off the monitors, they should cut through and not interfere with the FOH sound. If the room still booms cut some bass on the front of house sound too.

It might help to use the monitor graphic on the desk a little, if you find you need a lot of slider movement the problem needs to be sorted at source.

FarleyUK

Thank you - will give it a try at the gig on Saturday!

maltingsaudio

Take everything out of the mic below 100hz or even 150