Terrible acoustics at a bar

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jstancil

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I know this isnt exactly what you guys talk about here, but I figure you all would know the best solution to this problem.

I just started playing at a new sports bar and the acoustics are awful. Where I set up at and play I hear a ton of echo and at times it borders on feedback, lots of listening fatigue. However I have been told by all the people listening and working that it sounds great out in the bar. Part of this I just chalk up to they arent very critical of sound and as long as they can understand me it sounds good.

Here are the specifics, I play acoustic and sing by myself, pretty simple set up, no monitor just two mains. The room itself isnt that big really, but its a square with brick walls and concrete floors. I thought about hanging banners around the room but they have tvs everywhere and it would block them. I usually set up in one corner, just because there really isnt anyplace else to set up. I would think about moving everything around if you all thought that positioning myself in the middle of one of the walls was far superior.

So anyway, there you have it, an acoustic nightmare. Is there something i could buy and place around me that would help? Is there some special eq patern I could try that might make it a little better? Any help at all would be greatly appreciated. Thanks

Justin
 
Get as far away from the PA speakers as you can. Use a Galaxy Hot Spot or something similarly small and midrangy for a monitor.

You perform while the TVs are on?

Tim
 
Alright, so move the PA speakers farther away from me and use a small monitor? I can try that. The tvs are left on but nobody really pays attention to them, they are all muted. The problem with hanging the banners would be putting them up and taking them down every Friday night. If that will help alot I will try that out too, I dont mind throwing them up there each night. I was just trying to figure out a more constant fix for it. thanks for the tips though, that is a start.
 
Not sure what you mean by banners. If the problems are mainly in high frequency then drape-type material hanging around would help. If it's low frequency, that's not going to help.

For a performing location, getting away from corners is better.

Tim
 
It is the higher frequencys that I am having trouble with, so I might hand a few banners up. They would mostly just be sports type banners hanging fromt he ceiling around the center of the room. Thanks for the tips
 
I think if it were me I would make some tube type absorbers that I can place around me to absorb some of the sound slapping around. I have a friend who bought some a/c round rigid ducts (about 18 inch dia by 3 foot long) made of the compressed fiberglass. He filled it with loose insulation and sealed the ends with wood, covering the whole thing with burlap and mounted them to cheap mic stands. they work great in the studio as GOBOs as well.

It wont help with the feedback caused by a mic in close proximity to a speaker, but it will clean up a mushy smeared sound.

Tom
 
Getting out of the corner would definately help. I don't see how hanging banners would help at all.
 
If hgh frequency feedback is your main problem, there are many possible causes. First and formost is Mic/speaker proximity and position geometry. Especially in corners. Especially in high mass boundarys, such as brick/concrete walls and floors. These materials absorb little and reflect almost as much energy as they recieve. High frequency can be considered a ray, which when reflected off close proximity back/side walls which eventually reflect back into the mic. This type of construction contributes to a long RT-60(reverb time) which may or may not be a contribution to the sonic nature of what the audience hears, but it definetly contributes to feedback due to the number of reflections(reverb time) and the path time can also affect which frequency feed back. Long paths take longer to reach the mic. Also, RT-60 in small rooms have different decay rates for different frequency bands. However, the real problem in setting optimum response for a small PA, in a small room, is the audience itself. People absorb sound. If a sound system is adjusted for maximum response/volume with no feedback while a room is empty, the soundfield will change as the room fills with people. Which will alter your pa response as well. Normally, as the room fills with people, the sonic character of the sound will improve due to the absorption caused by more people.


As to stage placement, corners are notorious for modal(low frequency) resonance problems, but can also make it difficult to control high frequency feedback. Small clubs with this type construction, and a small corner stage can be a real headache to address sonic/acoustic problems of this nature, as small footprint tables are usually close to the stage unless a dance floor seperates the stage from the audience. Without the dancefloor, close proximity tables place a limit on placing speakers in FRONT of the mic. I know from 20 yrs of playing small clubs. :rolleyes: Your first line of defense in these circumstances is placing speakers as far foward in relationship to the mic.

Your mic of choice also has a bearing. Cheap mics are prone to high/mid frequency frequency because of bad rear rejection design. Shure SM-58 or 57's with a pop filter are good choices, although there are many.

Another possibility is a quality graphic EQ, and perhaps some type of small spectrum analyser as part of your setup. However, like I said, people change the overall response in the room.

As to reflections at the stage corner, personally for this type of venue/setting/music, I would make 2 broadband absorbers that can be either hung on the corner walls, or even straddling the corner behind the mic/performer. Either that or on some stand, or something to get the height centered on the mic height. This will help how you percieve your stage sound as well. Small corner stages can also contribute to comb filtering which can really make the PA sound like shit. These panels will remove most of these effects, at least within reason. They may also help with modal frequencies as well.



In consideration of the sonic quality of the MAIN soundfield, another possibility is the use of a Aural exciter. These offer a diffused type quality to the soundfield.

Well, thats my .02 anyway. ;)
fitZ
 
Last edited:
RICK FITZPATRICK said:
If hgh frequency feedback is your main problem, there are many possible causes. First and formost is Mic/speaker proximity and position geometry. Especially in corners. Especially in high mass boundarys, such as brick/concrete walls and floors. These materials absorb little and reflect almost as much energy as they recieve. High frequency can be considered a ray, which when reflected off close proximity back/side walls which eventually reflect back into the mic. This type of construction contributes to a long RT-60(reverb time) which may or may not be a contribution to the sonic nature of what the audience hears, but it definetly contributes to feedback due to the number of reflections(reverb time) and the path time can also affect which frequency feed back. Long paths take longer to reach the mic. Also, RT-60 in small rooms have different decay rates for different frequency bands. However, the real problem in setting optimum response for a small PA, in a small room, is the audience itself. People absorb sound. If a sound system is adjusted for maximum response/volume with no feedback while a room is empty, the soundfield will change as the room fills with people. Which will alter your pa response as well. Normally, as the room fills with people, the sonic character of the sound will improve due to the absorption caused by more people.


As to stage placement, corners are notorious for modal(low frequency) resonance problems, but can also make it difficult to control high frequency feedback. Small clubs with this type construction, and a small corner stage can be a real headache to address sonic/acoustic problems of this nature, as small footprint tables are usually close to the stage unless a dance floor seperates the stage from the audience. Without the dancefloor, close proximity tables place a limit on placing speakers in FRONT of the mic. I know from 20 yrs of playing small clubs. :rolleyes: Your first line of defense in these circumstances is placing speakers as far foward in relationship to the mic.

Your mic of choice also has a bearing. Cheap mics are prone to high/mid frequency frequency because of bad rear rejection design. Shure SM-58 or 57's with a pop filter are good choices, although there are many.

Another possibility is a quality graphic EQ, and perhaps some type of small spectrum analyser as part of your setup. However, like I said, people change the overall response in the room.

As to reflections at the rear of the mic, personally for this type of venue/setting/music, I would make 2 broadband absorbers that can be either hung on the corner walls, or even straddling the corner behind the mic/performer. Either that or on some stand, or something to get the height centered on the mic height. This will help how you percieve your stage sound as well. Small corner stages can also contribute to comb filtering which can really make the PA sound like shit. These panels will remove most of these effects, at least within reason. They may also help with modal frequencies as well.



In consideration of the sonic quality of the MAIN soundfield, another possibility is the use of a Aural exciter. These offer a diffused type quality to the soundfield.

Well, thats my .02 anyway. ;)
fitZ
Click to expand...
fitZ you really know your stuff. Glad to know if i have any problems i can come to someone like you. :D
 
Well, maybe not vehemently :=) Only disagreement I'd have is with the exciter - used one for a while in the rack, it kept getting turned up more and more til the sound could almost cut glass :=( - I finally took it out of the rack.

If you gotta set up in/near a corner, I'd buy or build 3 or 4 of these

http://www.readyacoustics.com/index.php?go=products.products&cat=10

in the "bass trap" version (4" thick) and fill 'em with local 703 or mineral wool - they look pretty cool (Joel sent me one for evaluation, it was blue, my favorite color) - simple and effective and PORTABLE. (sorta)

BTW, ALL sized rooms will have different RT60 at different frequencies, that's what choice of materials/treatments is trying to fix. The larger the room, you even need to calculate the high frequency losses caused by AIR. There are also Sabin charts for "well-dressed people in theatre loge chairs", etc ...

Possibly part of the problem you're having may be BECAUSE you're using no local monitors - you're likely hearing an echo from your mains that's as loud as your reflected sound from the stage, and it'll be about 1 millisecond per foot of round trip - so if the back wall is 30 feet away from you, you have a built-in 60 millisecond echo - think "elvis presley vocal" and you get the idea. This would be lessened some by more bodies absorbing the sound, but probably not eliminated.

Without a more exact description (or pix) of the area, that's about all I got... Steve
 
Damn, that is a lot of stuff that is over my head. You guys have given me a ton of tips though that I am going to try. Friday night a put the mains alot farther in front of me then before and I could tell a difference. It sounded a lot better to me. I am going to take some pictures this friday and post them on here, give you guys a little better idea what im dealing with. Thanks
 
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