Double Bass New to Amping Upright...

[Count Bassie]

In fact, pretty new to upright. I had some lessons years ago, and was recently given a bass in need of some tlc. Still working on the tlc part... but I picked up an MB112 combo (GK) to use it with, and played a couple Sundays at the church my wife's been handling the music for over the summer. We did some old-timey gospel, bluegrass, etc., and I found that if I turned the amp up a good bit I got feedback from the bass.

That may be obvious... but being I just had a little piezo p'up on the bridge, I don't get the energy coming back to the string that way. On electric I presume it's the pickup acting on the steel string in a loop of increasing energy. But my doghouse is just a big box, no magnet of any consideration really. How does this work? How do you guys stop it?

Thanks for taking the time, much appreciated.

 

[Marty Forrer]

Tell us about the piezo pup. Some are more prone to feedback than others. Also where you place the amp will have a bearing on it. There comes a point (or volume level) where you will have to start keeping the strings dampened with your hands, but I can play at very loud levels in my rockabilly band (I use a 500watt amp and 2 15" speakers for that band) just from having a very good quality pickup and employing a bit of string dampening with my right hand.

 

[Count Bassie]

Tell us about the piezo pup. Some are more prone to feedback than others. Also where you place the amp will have a bearing on it. There comes a point (or volume level) where you will have to start keeping the strings dampened with your hands, but I can play at very loud levels in my rockabilly band (I use a 500watt amp and 2 15" speakers for that band) just from having a very good quality pickup and employing a bit of string dampening with my right hand.

Well 'tis a Barcus-Berry Piezo. I use it into fDeck's HPF box, which is like an active buffered preamp. I had the GK combo more or less behind me and a bit to my left. I had the pickup, a little "H" looking frame with small thumbscrews, attached to the bridge on the bass side, each of the 2 screws set onto their own 'wing' of the bridge...

 

[gscroggin]

Do some searching (not saying you didn't) in the DB forum for "double bass feedback" or "feedback troubleshooting". There is a great top 10 (?) list that I think Uncle Toad put together a long while back. I actually have a modified version of it laminated and taped to the top of my AI head. When the going gets tough in a room, I turn to it and it's always had the answer.

I'll give you a hint though; 90% of the time the problem is my position with the bass relative to my rig, the PA, monitors, and the vocal mics. Especially in small clubs. IME DB can be downright tricky to amplify consistently at anything above traditional jazz sound levels, especially when you need to be standing in front of a vocal mike 50% of the time and be in front of your rig due to logistics...which is why I've cheezed out a bit and started using an EUB again for some gigs.

 

[Count Bassie]

Do some searching (not saying you didn't) in the DB forum for "double bass feedback" or "feedback troubleshooting". There is a great top 10 (?) list that I think Uncle Toad put together a long while back. I actually have a modified version of it laminated and taped to the top of my AI head. When the going gets tough in a room, I turn to it and it's always had the answer.

I'll give you a hint though; 90% of the time the problem is my position with the bass relative to my rig, the PA, monitors, and the vocal mics. Especially in small clubs. IME DB can be downright tricky to amplify consistently at anything above traditional jazz sound levels, especially when you need to be standing in front of a vocal mike 50% of the time and be in front of your rig due to logistics...which is why I've cheezed out a bit and started using an EUB again for some gigs.

Truth is I have not searched yet... but I posted between chores/events here at home last night, which is a place of high energy lately. I couldn't even frame the words to start a search with!

I'll go see that list, thank you very much, and maybe that'll do it. I am curious though, as to how this feedback thing physically works. I'll go do some science Googling while I'm at it.

Thanks Marty, gscroggin!

 

[dday110]

http://www.talkbass.com/forum/f4/stopping-feedback-loud-settings-413725/#post5450657


I have read that, and tried it, and still get feedback issues. I have the k&k trinity mic and wing pickup. I am looking at either a feedback eliminator, or the radial preamp that has a notch filter. I end up using just the wing pickup with my amp as the mic feedback too much, but when blended and using headphones, it's gorgeous! Any thoughts?

Don

 

[pnchad]

I hate to say it, because I have had them all including this BB with their preamp too, is not the best pup - not even the third best pup available

even an ancient Polytone is better in all regards to the BB

you can get something else for >$200 that will serve you better - watch ebay and check here

the Realist, K&K, etc. etc. - I'm using the Full Circle now and find it to work well

FWIW though, you will have feedback problems with DB just like an acoustic guitar - at a certain stage volume you'll loose the 'acoustic' aspect of the instrument and it becomes a huge fretless - so, if your bandmates can't accomodate a lower stage volume you're sunk

good luck

 

[gscroggin]

http://www.talkbass.com/forum/f4/stopping-feedback-loud-settings-413725/#post5450657


I have read that, and tried it, and still get feedback issues. I have the k&k trinity mic and wing pickup. I am looking at either a feedback eliminator, or the radial preamp that has a notch filter. I end up using just the wing pickup with my amp as the mic feedback too much, but when blended and using headphones, it's gorgeous! Any thoughts?

Don

Yes, IME in most settings, the whole mic/piezo blend thing just doesn't happen. Sounds fantastic at home though! At this point I've pretty much given up on a mic for anything other than quiet jazz or acoustic only settings, and just use my Upton Revolution. It's not a huge hardship for me as most of the stuff at the louder volumes is walking across ska/swing/rock, so I'm not after fine tuned tone and finesse. The Upton sounds great for that stuff. My (crappy) bowing is typically reserved for the quiet setting stuff and the mic really helps there.

I've tried all the notching stuff with my AI head, but it just doesn't help in most rooms with anything at moderate/full band sound levels. I've read/heard that there can be feedback performance differences between ply and carved basses (in favor of ply), age, how heavy the finish is (the whole "breathing" thing), etc., but I don't know that for a fact. Mine is carved and still relatively young.

 

[Ric Vice]

Yes, IME in most settings, the whole mic/piezo blend thing just doesn't happen. Sounds fantastic at home though! ....... The Upton sounds great for that stuff. My (crappy) bowing is typically reserved for the quiet setting stuff and the mic really helps there..

+1, I've tried to get blending to work, but IMHO, simplicity is what works best. Sending the DPA 4099B FOH, is simply the best. Using the Ehrlund EAP into the amp just works beautifully with my 5/8 Mircourt Bass, Walter Woods Amp
and the Audiokenisis TC 112. The Upton is a very nice pickup and sounds good, I have one in my gig bag as a backup.

When I used a Headway EDB-1, I always preferred the sound of the DPA 4099B over the sound of the Realist,
blended, or by itself. As the volume went up, and I had to add more pickup to the mix, eventually, the timbre of the Realist overrode, the timbre of the DPA, and I was right back to square one. The only difference being that I was carrying around the Headway, Microphone Cables, Patch Cables and all the other paraphernalia required to run the blender.

I've tried all the notching stuff with my AI head, but it just doesn't help in most rooms with anything at moderate/full band sound levels. I've read/heard that there can be feedback performance differences between ply and carved basses (in favor of ply), age, how heavy the finish is (the whole "breathing" thing), etc., but I don't know that for a fact. Mine is carved and still relatively young.

Personally, I'm beginning to feel that it has a lot more to do with the size and structure of the instruments top, than what it's made out of. Simply put, the bigger the top, the more prone it is to feedback. This isn't anything I can actually prove though, just my opinion.

Ric

 

[longfinger]

....
I am curious though, as to how this feedback thing physically works. I'll go do some science Googling while I'm at it.

In the simplest manner to explain it... the big box of the bass is not only a "speaker" , but also a "microphone" too. When your drummer plays, touch the bass and you can feel the drums move it. So the wood box picks up the sound of the stage, and send it through the piezo pickup, which sends it to the amp/cab, which creates sound which the bass top responds too, and sends it to the pickup....

Another thing tool in feedback control is playing technique. You need to dampen all the open strings that your not currently playing. That's not need in acoustic settings, where having open strings ring can give a nice sound. In highly amplified settings, muting technique becomes very important.

There are so many things to do and try. Go see and hear the double bassists in your city perform live, and ask them how they do it.

 

[Count Bassie]

L-finger, thanks for the run-down there. I hear the muting- in electric it's mostly what I'm doing! So fine- and if I can ever get out I'll try and hit some jazz gigs... nice info, thanks. Didn't realize the effect of low-level resonance in the body like that would do to the p'up- makes sense though, after an explanation.