The problems of using mics on URB include feedback and bleed from other instruments. Their are clear plexiglass products used to isolate drums. Also plexiglass disks used on the mic mount by horn players. Have any of you tried these with URB mic set ups? The drum product would have course have space limitations but the horn product would seem noninvasive. I would expect they would reduce feedback and bleed. I would also think they would alter the sound is it would create a mini-room for the bass. Experiences?
We used plexi shields for the drums in my church to keep stage levels down for the vocalists. Worked OK but was very inconvenient. We eventually dumped them and told the singers to get used to playing with a real band! I think they'd be totally impractible in a real-world giging environment. Don't know about those disks they put on horn mics, but I do know they wouldn't work for low frequencies because the wave forms are much larger then the diameter opf the disks. The factor that makes the most difference with mics is getting them close enough to the instrument - the inverse-square law says that halving the distance from source to mic give four times the level (and four times the signal/noise ratio). The best solution is to use a mic with tight directional pattern and mount it on or very close to the instrument.
I believe when horn players use those plexi discs they are for monitoring their own sound. Not isolation.They cause some of the sound to bounce back towards the players ears so they can hear themselves when things get loud.
Now that makes sense, because when I saw a horn section in a loud latin band using them, the mics were facing the drum kit, so the plastic discs would have been bouncing more drum spill into the mics. As a personal foldback system it's a lovely simple idea. Can't imagine it would be any use for a bass player.
I think Red Mitchell used to use a clear plastic shield, esp with a big band. Frankly, I think it would be a pain in the butt to carry around, plus all the jokes you'd get from the band members . . . also, the amount of acoustic sound that the rest of the band hears would be seriously decreased.
Actually this is not such a weird idea. Just last week I did a show where I wanted to use my AMT but I was in a position right down in front of my big band and facing them side-on to cue and conduct certain things. See the pic here: http://www.impressionsinjazz.ca/gallery/v/2007-2008/CP-021207/CP-021207-23.jpg.html My speaker was up the back between the drums and trumpets in case anyone is wondering. Anyway, in most other situations I play in, I'm facing forward and the body of the bass shields the mic but in this situation for various reasons I would have had all kinds of horns blowing across the mic. So I was hoping to use some baffles like I've used in a recording studio, to shield the bass. The baffles I've used and had in mind are not made from plexiglass but are thicker like small walls and they have some kind of fabric covering. I've never really taken too much notice of them in the studio. Unfortunately I only thought of it a few days before the show and couldn't find anything that was low enough so that I could comfortably see over it.
one of the problems with miking an URB is the reflection of other instruments off the body of the bass in to the mike. If there is a barrier between the mike and the rest of the room this will be decreased (as would the feedback). The "popemobile" 4ft x 2 ft clearsonic panels should work. Of course they would be a pain to haul around, but it might be worth it for some gigs. Someof the delicate sounds of the instrument could be lost on the rest of the band and the audience but that is the purpose of the mike rather than a pickup. I was wondering if the horn player discs, the 12" ones, might have some effect on the reflections off the bass, or maybe not.