Double Bass Darn near blew up the PA

[Nagrom]

Last weekend I was playing outside.
String bass-Shadow SB2 piezo- Fishman ProEq preamp-VT bass deluxe (on bypass). The preamp was sitting on the stage, a couple of feet from the sub. I kept the VT in the loop for its XLR to the board, as I was also doubling and the festival provided no amp.

EB worked perfectly through an earlier set with another artist. I switched to DB, as noted above, and got a horrific, and intermittant, sub-howl that forced me to abandon the DB after the second song.

The preamp seems to have gone microphonic, but I used the preamp again on Wednesday, with a different DB, without incident for a couple hours. I cannot get the pickup to act up either. The VT D.I. box functions perfectly. Cords are all decent quality and in apparent good order.

The feedback incident was epic. Any thoughts on the likely cause & fix?

Thanks folks.

 

[moles]

What makes you think this is the pre? More likely FOH eq settings not playing nice with your DB.
Was your set on Wed through the same system?

 

[bassdaddyfive]

Sometimes it's the person behind the board. Little experence with DB with subs. Been there and done that..........

 

[Nagrom]

Different system on Wednesday. I'm sure this is gear-related. Everything was going fine, then all of a sudden BAWOOOOOOOO.... Bounce the bass, kick the pre, gone for a bit, then BAWOOOOOOOO.... Like I said, the pre seems to have gone microphonic.

 

[SAlcott]

I tell the sound guy to lose EVERYTHING below 35-40 hz on the bass channel.

 

[fdeck]

A good loud Bomb on open E will usually take care of the subs for the rest of the night.

Don't ask me how I know this.

 

[Kael]

You were sharing an XLR send for both bass guitar and the big bass yes? If that is the case, it strongly sounds to me like the FOH guy had you dialed in with extra low end EQ on the bass guitar. When you switched over, all that extra EQ'd in low end produced the elephantine mating calls you heard. Since the fishman has an XLR send also, try telling the sound tech to give you two channels next time and make him aware that he should not approach EQ'ing your double bass like a bass guitar.

I actually get away with using one send occasionally when doubling. Use a SABDDI for the bass guitar and a Fishman for the double bass. When I do this I make sure to tell the soundman to NOT do any extra EQ work on the single bass send as EQ for one instrument won't translate when I swap out basses. This isn't the optimal method IMHO, but it has worked for me upon occasion in the past. When doing this I make sure to mention to the sound tech that if he needs more/less of anything to ask and I'll tweak it from the preamps on stage. Really though, two sends work better IME.

 

[Nagrom]

My Fishman is 20-years old, just an preamp EQ with no XLR.

Thanks for the info.
I need to rephrase my question...

Do solid state devices like old Fishman's go microphonic at the end of their lifecycle?
Mine seems to have. Is it terminal?

 

[Kael]

No, they shouldn't go microphonic. You stated that you used it subsequently without problem. That plus the way this issue occured still has me suspecting this was a case of the FOH tech EQ'ing for your bass guitar and then not changing when you switched instruments.

I hadn't realized that older fishman pre's did not have an XLR. That makes it a little more problematic. I suppose you could always use a simple passive DI after the preamp and still run two signals if need be.

 

[iiipopes]

Francis posted above -- he was too kind to advocate his own product, so I will: get his fdeck in the loop so you can selectively roll off the bottom end as necessary to keep from rumbling. That's what I do, with the $70 version to get what is effectively a gain trim as well. Work with it at home until you get an idea of the difference in the response of your EB v DB, and you'll never have to worry about an inattentive tech again -- or blowing the PA!