Mic picking up bass, causing feedback- other issues

drbassman · December 22, 2011, 02:28:30 PM

When I was at practice this week, I noticed that my mic (I do sing some backup once in awhile) was picking up my bass and causing some feedback and other weird sounds through the sound system. Any suggestions how I might minimize this? I was thinking a highly unidirectional mic aimed away from my amp with a screen might help. Any audio engineers or wannabes in the crowd who can help? I don't have a problem buying a good mic if that's what it takes.

Also, I notice a lot of resonance issues when I hit an open E or a B. It vibrates the drummer's bass drum like crazy and then ends up distorting my notes. I realize we have a resonant frequency issue here between us and I'm going to move my cabs as far away from him as I can. The drummer is also considering a screen since our club is small and we are in tight together when we play. I suspect that could also end up deflecting some of my sound waves, although low frequency waves are more prone to vibrate any surface they encounter vs. bounce off like mid and high frequencies do.

Any practical suggestions and theorizing is appreciated!

Pilgrim · December 22, 2011, 04:58:28 PM

Bill - things you probably already know -

- Your voice often sounds better going across a mic than directly into it. I almost always use a mic at a 45 -degree angle to my face. This may give you some ideas with mic placement..and if the mic is a cardioid, definitely use this to point it away from the cab.

- Any physical object between the speaker cab and the mic (like your body) will tend to mitigate sound wave transmission to the mic.

- If the bass is a hollowbody, try stuffing some soft material inside to kill sound bounce.

Freuds_Cat · December 22, 2011, 06:11:56 PM

Doc, harp player in one of the bands I play in has a mic with a switch. Because he only had small parts in the songs we found it cleaned up the stage sound a bit if he turned it off when he wasn't playing. Not always practical but just sayin'.....

Pilgrim · December 22, 2011, 08:31:25 PM

Good idea. In the larger scheme of things, I dislike on/off switches on mics because they are inevitably the thing that breaks - making an expensive mic useless (until repaired) because of the failure of a $1 part. BUT - in this case, it might be a good idea. A mic that's off can't feed back.

If your mic doesn't have a switch, here's a $22 on/off switch that goes in line in any XLR cable.....I'd get a 1 foot XLR cable, connect it to the mic, insert this switch, then connect the regular XLR cable.

http://www.markertek.com/Connectors-Adapters/Audio-Adapters/XLR-to-XLR-Adapters/Calrad-Electronics/35-465.xhtml

Freuds_Cat · December 22, 2011, 08:42:53 PM

Footswitch is a much better idea, especially if your hands are full.

Pilgrim · December 22, 2011, 08:55:43 PM

Quote from: Freuds_Cat on December 22, 2011, 08:42:53 PM
Footswitch is a much better idea, especially if your hands are full.

Dangit, you have this habit of being right!

http://www.bhphotovideo.com/c/product/725925-REG/Whirlwind_MICMUTE_PP_Micmute_PP_Push_On_Push_Off_Audio.html

Freuds_Cat · December 22, 2011, 09:11:21 PM

Maybe, but you have better research skills. I couldn't find any.

Merry Christmas to you both

mc2NY · December 23, 2011, 09:48:42 AM

1) Move the mic placements a bit from directly poining at any backline amps/drums....then possibly add a compressor to your PA and adjust out the low level volumes the mics are still picking up. You might also try one of the feedback exterminators like those made by FBX, that automatically knock down whatever frequency is in your PA and about to feedback (also called a notch filter.)

2) Maybe try adding a Thumpinator tp your bass to remove unused transient frequencies that are rattling the drums and walls.

http://www.sfxsound.co.uk/mainpage.asp?page=micro_thumpinator

Psycho Bass Guy · December 23, 2011, 06:04:49 PM

I'll bet money that it's not so much your mic being the problem as it is your soundguy is putting too much low end into it and he probably has the subs (read kickdrum) far too loud, which means all the lows/bass leaking into your mic are being reamp-ed through the subs and stage monitors, making the drums rattle too much. Since you're not singing lead or doing bass vocal harmonies, just sharply roll all the low end off of your mic below 2-300Hz. It'll sound like crap solo'ed, but in a mix, it will sound completely natural and should solve most of you feedback trouble.

You'll also have less problems with standard polar mic patterns ("directionality") than ultra-directional mics, especially with the low frequencies. Cardioid is the standard for 90% of vocal mics and with good reason. They provide reasonable rejection of off-axis sounds, but in mics with tighter pickup patterns, 'hotspots' occur behind the mic due the physics involved making the mic more unidirectional.

Finally, I strongly reccomend against any kind of on/off switch. It's an unnecessary additional layer of complexity that doesn't address the real problem: if your engineer can't set up a backing vocal mic to NOT feedback onstage when not in use, you need to upgrade your engineer.

Pilgrim · December 23, 2011, 06:54:33 PM

Quote from: Psycho Bass Guy on December 23, 2011, 06:04:49 PM
Finally, I strongly reccomend against any kind of on/off switch. It's an unnecessary additional layer of complexity that doesn't address the real problem: if your engineer can't set up a backing vocal mic to NOT feedback onstage when not in use, you need to upgrade your engineer.

I can't argue. I don't like the darn things, I just thought it might be a solution of other tricks din't work.

I also agree with the EQ rolloff and a more directional mic. Both should help - and playing with the EQ should help to isolate the feedback frequencies.

drbassman · December 25, 2011, 05:29:36 AM

Great suggestions guys! We do have a lot to work on sound wise. Our lead guitar player is doing sound for us until we can find someone to help us. As a new start up band, we're just getting off the ground and I'm going to try the more directional mic and roll off ideas. Moving my cabs should help some too. He was experimenting with the kick drum mic, and that's adding to the problem as well, I think.

Thanks guys, great suggestions!!!

BTW, I started playing the Gretsch 5123 but once the band got to volume, feedback and resonance issues made it unplayable in our tight venue. So, I'm playing the Thunder Jet and the Triumph. Good options!

Pilgrim · December 25, 2011, 12:24:17 PM

Quote from: drbassman on December 25, 2011, 05:29:36 AM

BTW, I started playing the Gretsch 5123 but once the band got to volume, feedback and resonance issues made it unplayable in our tight venue. So, I'm playing the Thunder Jet and the Triumph. Good options!

No surprises here! That's a true hollowbody, and a big one at that - probably worst case for a small venue.

I've sold two basses recently and about to sell the third (I hope) and I'm planning on a Thunderjet in their collective place.

drbassman · December 26, 2011, 05:13:41 AM

I love my TJ. Great neck, pickups and comfortable, not heavy.

patman · December 26, 2011, 08:10:17 AM

use an SM58, and make it so the backline is not blowing directly into it....

Freuds_Cat · December 28, 2011, 04:37:14 AM

Yep I agree PBG. All of that makes sense when dealing with experienced musicians and sound guys and decent gear. Sometimes unfortunately we have to play with a set and forget or side stage self mix situation in small venues or guys with crap gear or a lack of experience. These days I find it easier to just stay out of offering advice to other muso's or sound guys on the same stage as me if I'm "just the bass player". If its my gig then its different.
One guy who regularly plays with one of the bands I'm in is totally unshakable in believing that his harp sounds awesome through this ancient clapped out Shure mic. It doesn't and it causes a lot of problems but as I said before I'm not interested in buying into the discussion.
I just concentrate on having my sound together and leave 'em to it.