Double Bass Feedback caused by after-length

[Mutant...]

Hello bassists.

I've been playing upright for nearly two years and am currently using a revolution solo II pickup, which is great, I'm really happy with the sound. The only problem I'm having is feedback due to the string after-length (behind the bridge).
The pickup came with an after-length dampener which helps, but not enough. I wrapped it in fabric last time I played a new venue and that solved it, but the other night I played a high volume rock/alt gig and my problem returned. This thing won't shut up! I ended up stuffing my guitarists gig towel in there. That fixed the problem, but I'll probably be playing even louder gigs in the coming months.
Today, I plan to try a few different materials for dampening. Is this my only option here, or am I missing something? I thought one of you fine folks might have encountered this problem and perhaps have a more elegant solution than a battered towel stuffed in the strings.

Regards
Jesse

 

[fdeck]

My "theory" is that every setup has a threshold of gain, where it becomes unmanageable due to feedback. The threshold could be a function of your bass, pickup, electronics, speaker, the placement of the speaker, and even the room. Furthermore, every measure to increase that threshold, e.g., through damping the resonances of your bass, move you further away from the natural tone of your bass.

For really loud music, a magnetic pickup might be a better compromise. This would be at the point where you are far beyond preserving the natural tone of your bass anyway. The magnetic pickup will have a considerably higher feedback threshold because each string is basically acting as an ideal narrow band filter tuned to the note that you are playing.

The only other option is for the entire band to manage the volume levels on stage, around preserving the acoustic tone of your bass.

 

[robgrow]

Francis (fdeck) is right. I'd look into a Krivo magnetic pickup.

 

[Mutant...]

Thank you for your advice, the Krivo looks like the tool for the job. It will have to wait until I can afford it, however.
I hadn't considered that dampening that part of the string could affect my tone.

 

[powerbass]

I use a Genz Benz Shuttle 3.0, I use the Mid preamp filter on the amp to reduce feedback, also I place the speakers in front of my bass

 

[Ric Vice]

My "theory" is that every setup has a threshold of gain, where it becomes unmanageable due to feedback. The threshold could be a function of your bass, pickup, electronics, speaker, the placement of the speaker, and even the room. Furthermore, every measure to increase that threshold, e.g., through damping the resonances of your bass, move you further away from the natural tone of your bass.

+1 ∞

Listen to what FDeck has said. You can damp the after length, turn sideways, and plug the f holes etc., and all you end up with is a really big bass guitar IMHO. If that's the sound you desire, then go for it. I played at a session last evening where a great local bassist named Chris Watrous used his 8 string electric bass with in a guitar trio.
He's mastered the instrument (which he built by the way) so completely that, if I closed my eyes I truly, didn't hear a difference tonally, between his timbre, and an uprights. Looks can be very deceiving. I love the DB, it's my main instrument, but there are musics and playing situations where the Electric is just a better choice. IMHO.

For really loud music, a magnetic pickup might be a better compromise. This would be at the point where you are far beyond preserving the natural tone of your bass anyway. The magnetic pickup will have a considerably higher feedback threshold because each string is basically acting as an ideal narrow band filter tuned to the note that you are playing.

My first real pickup was that "little silver bar" that Barcus Berry designed, it sounded terrible, so went back to using my Fender Jazz Bass, on all the gigs I played. Next up was the Polytone, I used it for a few weeks, and went right back to the Fender. Then somewhere around 1975, I went with a Toby magnetic, that worked fine, it didn't sound like a bass but it worked. Newer pickups like the Underwood, Realist, and Ehrlund allowed me to play the upright on gigs. All these pickups have a volume threshold where the pickup changes character, or starts feeding back.

The only other option is for the entire band to manage the volume levels on stage, around preserving the acoustic tone of your bass.

There's a thought! Personally, I'm very tired of all the over amplified music at concerts and clubs. But then that's just my opinion.

 

[Mutant...]

There are many good reasons for playing one of my electrics instead of this hoary, chipped, bulky, inconvenient, expensive, fragile and feedback causing instrument.
I can't, though. I love the middy tone, the subtle textures, the grind when you play it really hard, the way a note 'comes on' after you pluck it, that particular growl from a well placed slide. No, sir, the upright is the one. Damn, reading through what I like about it, it sounds like I'll lose a lot of that with a magnetic pickup! I suppose I could have the magnetic pickup running to amp and monitors, and still run the rev solo through FOH...
As to the idea of keeping managable levels on stage, that would be ideal. However, while I have a great deal of confidence in this band we're very new on the scene. We might play after a Metal band one night, a pop-classical duo the next, or in between an indie and a thrash group. We don't always get the opportunity to tweak everything just so, and probably won't until we start running our own shows.

 

[Jimnastix]

I played UB in a glitsch electronic outfit for a while and used in underwood. Often there were massive subs etc so feedback was always close.
IME low stage volume & monitor speaker in front (even at ear level with little bass in the eq) will help. Let the FOH pump the sound. Splitting the signal e.g pickup to the desk and magnetic pickup to amp might help.
Try using a compressor, perhaps eg the 'really nice compressor'.
Also a high pass filter or better a sweep able low cut can help isolate the problem frequencies.
Good luck!

 

[tornadobass]

I picked up an idea from my Azola BugBass that came with a strip of velcro wrapped around the afterlengths. It's a little more effective than the tube that Upton provides and if you use black velcro, it doesn't stand out visually. It gives the sound a bit more focus, although it might reduce the upright bass character a little bit. My pickup is a BassMax, which still reproduces the essence of the upright sound with the velcro in place.

 

[MostlyBass]

I've put a tennis or racquet ball between my bass and the tailpiece to stop sympathetic vibrations and feedback.