New AV system for School

[JimmyRosa]

Hi all,

 

 

I've been given the task of purchasing a new AV system for the hall at the school I work at in Surrey near Guildford.

 

The current old AV gear we have in place is a OSC Audio USA 850 amp, Yamaha graphic equalizer Q2031A, CD drive, tape drive, mixing desk - Sound craft Sprit Follo RAC DAC sound desk and a set of 4 x loud speakers.

 

The current AV wiring for the system causes feedback so we need to sort this but are reluctant on spending too much on the wiring as the AV system needs to be moved to a new building in 2 years unless the wiring loom can be moved and re-installed?

 

We would also like to demo the AV gear in the Hall where's it's going to be installed before we purchase.

 

So I'm looking for any decent AV suppliers/installers to come out and give us quotes?

 

Cheers,

J

[fiza]

Try @Millgate ?

[nicholab]

The wiring will not cause feed back the wiring cannot crate a feedback loop. Radio mics are the worst for feedback ideally you use a feedback exterminator with them. Also remember the feedback threshold decreases by 3db for ever mic you have open.

[BennyG]

Are you only getting feedback when using a mic (wired or wireless)?

I would consider looking at the settings on the Yamaha graphic equalizer. You can use the graphic eq to cut/reduce the frequencies that are causing the feedback. I would also look at the eq settings on the channels on soundscraft desk too and microphone placement.

 

If you are getting feedback whilst using a CD or anything other than a mic then something a little stranger is happening!

[ben604]

As the above have said, it sounds like a pretty decent system, I'd be looking at the use rather than replacing outright. Maybe the positioning of the speakers relative to the microphones - we moved ours down our hall by about 3m and that helped a great deal when using the mics on the stage. Also, the careful use of gain on the mixing console will help! Some people boost too much at the gain stage and that causes issues. Oh yeah, get people to talk into the microphones from as close as possible!

[JimmyRosa]

Thanks for all the replies guys, really appreciate it.

In the mean time I will check and test the recommendations regarding the current setup.

I meant to say feedback comes when using mics, but there is a slight crackle in the system when using other audio too which I will investigate. We don't have a person that solely looks after the AV but I'm interested and put my hand up when told about getting a new system.

 

The school wants a new system anyway and has budgeted for it (not my choice) it's also going to be used in a new building once finished.

[john]

Thanks for all the replies guys, really appreciate it.

In the mean time I will check and test the recommendations regarding the current setup.

I meant to say feedback comes when using mics, but there is a slight crackle in the system when using other audio too which I will investigate. We don't have a person that solely looks after the AV but I'm interested and put my hand up when told about getting a new system.

 

The school wants a new system anyway and has budgeted for it (not my choice) it's also going to be used in a new building once finished.

 

Is the new building the same size, acoustic design and layout of the current? If so great but if not then wasting money just saying that, it would be best to sit tight and wait, or design for the new building and maybe fit to the current one compromising bits. Every space is different.

[psydii]

A surprising amount of the cost of a decent PA is in the cabling, which is quite difficult to re-use between installations.

 

On the topic of feedback, i am very very far from an expert, but recently I was sat in front of one of these:

Allen & Heath GL2400-432 Live Desk

and had to deal with some in front of a 400 attendee event... dropping the gain and pushing up the faders on the channels affected had the desired effect.

[antlear]

Have you got any where with your issues yet?. Is there a loop amp in the hall at all as these can cause issue and cause feedback it close to mic cables. check your gains. and your eq on each channel. Also you could ring out the feedback with the yamaha graphic. I am in Hertforshire way, if you want your system looking at i would be happy to do so for a cost. I could give you some ideas and reccomendations for a new system and potential suppliers. I work as a full time av technician and have designed and install systems for people.

[JimmyRosa]

Hi all,

 

Yes sorted this out on Friday. Soundcraft mixer is faulty. Connected new small mixer and the 2 existing wireless mics and one wired mic, corrected gains as said, re-positioned speakers. All seems in order for School open day. Defo good mic technic is needed too!

The main issues were , position of the speakers, soundcraft mixer not working, plus the gain setup.

 

 

Really appreciate all the replies, thanks!

J