Horrible feedback

[MillburyAuditorium]

Well, we have gone through this every year, and not much we can do about this.

Well, there are four speakers in our house. two side and a center cluster of two. When the auditorium was built, these speaker where in front of the stage, the stage used to have a flat front and end at the proscenium arch with stairs at either end. But since then it was remolded, before I got here, and now it has a nicer, curved front and horizontal stairs, but, now the front of the stage is in front of the center cluster. So during the production season where more then one or two mics are needed we need to disconnect the center cluster because it just makes a big loop and gets horrible feedback. The floor mics will pickup sound, go through cluster and go right back to the floor mics since the speakers are pretty much pointing at them. And it is even worse with the wireless mics.

The only solution I can see if get a new speaker set and move the cluster forward, or move the sides forward, almost to the stage, and get two new speakers and have them in middle.

Also doesnt help one of the tweaters in one of the cluster speakers is blown and we have a mono system. :/

 

[MNicolai]

At least many of today's installs are very finely tuned. When our facility was built, a lot of different factors were considered when choosing which speakers to use and where to put them. That included using software to map out and calculate how sound waves propagate throughout the room. After the install they proceeded to measure the room out and program the DSP's feeding the speakers to calculate delays and provide subtle equalizations to tune the entire room. Your ideal solution would be to contact an audio installer to examine your room and come up with a new center cluster for you. You could simply replace the bad speaker and be done with it, but if you have to disconnect the speakers regularly you might as well not have them. If you are going to put any money into a solution, make it a solution that you will be able to use.

 

[museav]

Don't know what their scope was or what they were told to do but whomever modified the stage should have considered the impact on the audio system, in simplest terms what was once audience that required speaker coverage is now stage where you don't want that coverage. I wouldn't be at all surprised that you may have some issues with lighting if that was also not considered. But since they apparently did not account for this simple issue, there appears to be two general options. One is to ignore the stage modifications and use the stage as though the changes had never been made. The other is to modify the speaker system to reflect the changes to the stage. With the latter you might as well also address any other desired changes at the same time.

You note having a mono system, however having left and right speakers along with a center cluster suggests that the system might have initially been designed as an LCR or stereo plus center mono system. The left and right speakers could be side fills or it might be an exploded mono cluster but your using the system without the center array indicates that is probably not the case, it it were then disabling the center cluster would likely result in very noticeable gaps in the system coverage. Establishing and reconciling the general system concept both from the perspective of what was intended and from what is desired could factor in to any decisions.

As Mike noted, system adjustments and tuning can be critical to the final result and could provide a significant improvement. However, without introducing other negative aspects, tuning will probably not be able to compensate for what sounds like a coverage or aiming issue. It might be that some adjustment to the existing speaker aiming along with some system tuning could be sufficient. Or it might take different speakers and/or different speaker locations in order to achieve both the desired coverage of the audience and sufficient gain before feedback with the revised stage. To make any determination would take assessing the changes made to the stage and seating, the potential speaker locations, the speakers themselves and perhaps also considering any other existing issues or factors, such as the apparent blown tweeter. It may also be a good opportunity to go through the entire 'B Chain' or from the console outputs on and optimize the system.

 

[SHARYNF]

This is SO typical of poorly planned modifications that never take into consideration the audio side of things, just the physical construction.

Someone needs to have the install looked at, and modifications recommended. I would guess like Brad says that you are looking at Aiming Issues, and probably some sort of alignment delay correction. It is the classic there is never enough time and money to do it correctly the first time, but now additional funds are going to be needed to fix it.

Simply turning off the center cluster probably is not going to be a reasonable solution. If I remember correctly your venue had a whole set of issues re a surround sound install??? The setup looking back over some of the earlier posts seems to have been done sort of home brew install?????

Sharyn

 

[MillburyAuditorium]

Thanks guys,

Well, our setup is designed to have a nice surround sound, but the contractor ran off the with speakers during construction, so the school purchased two speakers for a center cluster and took two from the stadium that was being built.
There are just so many holes in our sound system and we have the potential to have a great sound system, but no one ever followed up on it.
Our theater is undergoing a lot of upgrades, we will probably in the next year or so be, getting a new light board, eight new wireless mics to match the two new ones we recently purchased, have someone come in to completely redo our sound system, re-paint the house, build a booth, and get a new rear traveler curtain since the current one has a huge rip in it.

And about lighting being affected. It is not to noticeable, but we only had to move the FOH spots down a bit, and there is no above coverage on the front part of the stage since it juts out from the proscenium arch now.

So many good intentions in our place, but non followed through.

Oh, Another thing about good intentions, I believe we were supposed to have more spotlights, We have a FOH bar with 16 spots on it, but we also have two bars on the sides, near the middle of the house, near the speakers, that I have seen used for lighting, with nothing on them.

We should just get a grant and rebuild completely
But hey, its a highshcool auditorium, what can I expect.