Solutions for reducing feedback from an amplified cello?

January 9, 2009 12:03 AM

We use a clip-on-bridge pickup ($20, but it sounds fancy) to incorporate cello into our 5-piece rock band. The cello is always the volume-limiting factor, though, and we'd like things to be a little louder. There seem to be no sound hole covers on the market, and we're not stuffing the whole thing with socks, so we're looking for anything that will reduce feedback and easily attach to the cello without having any, any, ANY permanent effect on the instrument.
posted by worstnerdever to media & arts (8 comments total)

This may be insane and/or ineffective. But you could sew a custom cover for the body of the cello that would cover the back, sides, and all the front except the strings and bridge.

Heavy enough fabric would cover the holes and reduce feedback and sympathetic vibration. A soft fabric would actually protect the instrument, too.
posted by The World Famous at 1:01 AM on January 9

I play(ed?) upright bass, and used a piezoelectric bridge pickup for playing in jazz and pit orchestras. I had a lot of problems with feedback.

Nothing mechanical really helps. Covering the f-holes just screwed up my ability to really hear what was going on. You can't stuff one of these instruments without seriously fucking it up.

The thing that I found helped the most was to make sure that I didn't have a monitor anywhere near me. It also helped to talk to the sound guy and have him mix me down to the very edge of inaudibility on everybody else's monitors--except in jazz band, which was mostly pizz anyway. If I found that I couldn't hear myself over, say, the drummer, I usually preamped the pickups and split off a line for a pair of headphones--looks goofy, but works fine.

Depending on your budget, you also might try one of those plexiglass shields they put around people in the studio (or occasionally around drummers on stage). I had great success with that the one time I had an opportunity to use it. It really worked the best out of anything, and had the least compromises in terms of mixing, monitors, and sound.

The problem is really that the body of a string instrument is an excellent amplifier, and also contributes significantly to the timbre. If you monkey with the instrument too far, it stops sounding right.
posted by Netzapper at 1:48 AM on January 9

can you try using a free-standing audio baffle (like an audio tile, but standing vertically) around the cello and player? that may help you get a few more DB before the inevitable feedback kicks in. There's a few of them here.
posted by jenkinsEar at 4:07 AM on January 9

IANACP, but I agree with Netzapper -- a couple things will help.

1) the Baggs ParaAcoustic DI -- it is a genius box that will help you send better signal to the PA and will help notch out frequencies that have a tendency to squeal.

2) improve the pickup -- the fiddle player in my band uses a special bridge with the pickup built-in.
posted by omnidrew at 8:08 AM on January 9

I used to play cello in a 6-piece rock band that got pretty loud sometimes. While a mic provided the best (most like acoustic) tone, there was no way around the feedback problem. It's always a compromise between volume and tone for the reasons Netzapper identified above.

When volume needed to take precedence, the best solution I found was to use a piezoelectric bridge pickup (A Fishman C-200) plugged into the same Baggs preamp DI that omnidrew mentioned above. I'd use that for playing live, and then for recording use the best condenser mic I could find and just fix the levels in the mix.
posted by dr. boludo at 9:08 AM on January 9

A rock band can ALWAYS outplay a cello. Doesn't matter what kind of fancy pickups and baffles and so forth you get. Good equipment (mentioned above) can go a long way towards bringing the cello up into the rock world, but it will always be incumbent upon the rest of the band to not overplay.

When you bring instruments that are essentially portable resonating chambers onto a stage with electric instruments, there is no way around this issue, short of a clear plexiglass box (which I've used, but it was far more trouble than it was worth).

Good musicians will make sure that there's enough "room" for everyone to be heard. Poor musicians will wonder why they can't hear anybody else when they're playing, and suggest that everyone turn up. You know, cuz it's "rock".
posted by Aquaman at 9:39 AM on January 9

Placing barriers between the monitors and instrument should be an effective approach. If you don't want to pay and arm and a leg for the fancy plexiglass barriers you can use a heavy piece of wood (the denser the material the better it blocks sound). I use 4'x2'x3/4" sheets of MDF bought precut from Home Depot to isolate my drum set, they work great and cost about $10 each.

If you don't want to go the barrier route an automatic feedback remover like this will help. It "listens" for feedback and tunes a notch filter to the feedback frequency, removing the feedback with a minimal impact on tone. I used to use one on the vocal mic / PA back when I played in a LOUD rock band and it worked well, only pain was you had to clear it out and let it reprogram itself whenever you moved things and changed the acoustics of the room. Right now mine is collecting dust in a cabinet somewhere, if you want it I'll hook you up.
posted by waxboy at 12:10 PM on January 9

I, too played cello in a loud band for quite some time.

I found that in big venues with good sound people, a good pre-amp and pick up, there was never a problem. The rest of the time I usually wanted to shoot myself.

One thing that helped was filling my cello with shipping peanuts. It would not be "permanent," but it takes a good 45 minutes to take the peanuts out if you need to, so that would not be something that you would want to do frequently.

Ultimately, I just bought an electric cello to use in live performances and I am much happier with that. There really is not going to be an inexpensive solution.
posted by free pie at 12:58 PM on January 9