Double Bass Need some help chosing pickup

[DavidRN]

Hello, I bought a EUB not to long ago. It is from China and has spent many hours at the luthier to get it playing properly.
It has Eva Pirazzi strings on it by the recommendation of Gollihur music. I have come to find that this is probably not the best choice as I cannot use a magnetic pickup with these.

I am having issues with tone. I tried a K+K bassmax and found the tone to be uneven across the strings. I think this is related the the shorter bridge. I tried a Fishman BP-100. It was way too treble sounding. It was better under when I mountedit under the bridge feet with cork. I also went to a Behringer EQ. This has helped with the nasal quality of the tone.
However, the tone is still to bright sounding for me. I love the grunge sound I am getting. But it justs sounds too thin. And, the tone changes each time I play the thing.
I am using an Acoustic Image amp. K+K pre amp also.

Not sure what to try and I am a little leary of the wing mounted pickups after hat happened with the K+K.

Any thoughts?
I thought about using a Wilson but, not sure if the treble issue will return with the pickups mounted towards the strings. The Fishman Full Circle is a thought too and is what my luthier recommended. Also heard Realist may work.

 

[Francois Blais]

The BP100 needs a preamp with a very high input impedance.
10megohms is ideal.
The K&K preamp only has around 1Meg and may explain the thin sound.
The Fishman BII preamp is inexpensive and my favorite unit, and matches the BP100 perfectly in terms of impedance.

Do you have pics of the EUB and closer shots of the bridge?

 

[DoubleMIDI]

Don't use cork under the bridge feet, it needs to be something solid or the bass will be damped too much.
I used a piezo disk, cut into a rectangle and put in a 3mm piece of wood where I cut out some wood for the cable contacts. So the pressure goes onto the piezo ceramic.
If the output is too low put a sheet of cardboard in below the metal disk and some ver thin spot of metal on the middle of the piezo ceramic to get a bending which gives more output.
But don't use more than one sheet of cardboard or you might get more bass loss than you want.

The Wilson under the strings will give you the string sound, sounds a bit electric. You might want to use a single wilson in the E bridge foot.

The Realist only works if you have a solid table to put it on, so also here no cork.

For a first cheap solution try replacing the cork under the K&K with a single medium thick piece of cardboard.

 

[DavidRN]

The BP100 needs a preamp with a very high input impedance.
10megohms is ideal.
The K&K preamp only has around 1Meg and may explain the thin sound.
The Fishman BII preamp is inexpensive and my favorite unit, and matches the BP100 perfectly in terms of impedance.

Do you have pics of the EUB and closer shots of the bridge?

Hi, I have heard that the Fishman preamp may be the way to go. But, it was just a few days ago. Right now I can not get any pics of the bridge as the tail piece blew out right after I finished a festival gig with it.

You can see a few pics here
Link Removed

There are also a couple files of this bass ROGTJB tunes St Louis Blues and Pennies from Heaven. Not my best work as I was fighting the bass and the sound guys all weekend long!

Doublemidi, I used the cork to try to tone down the fishman pickup as it was really tinny and harsh. The cork is not part of the bass. It was just a trial thing to get it through the festival I did.

 

[DoubleMIDI]

Hey David,

I'm afraid I read your initial post too quickly and missed that you tried the cork with the BP100 (I thought you tried it with the bassmax).
And I assumed that you put the cork on the body side of the pickup.

But anyway. I tried bycicle innerrubber tube between a piezo disk and the massive top (trying to decouple noise from the body) and didn't got any good sound. (This was using a piezo disk in pressure mode I haven't tried it in the bending mode.) So I went back to wood and cardboard.
The piezo needs pressure from both sides in the whole frequency range. A soft material close to the pickup will absorb too much in some frequency range.

Sorry about your tailpiece, you were still lucky that it didn't happen before you had to play there. My Clevinger doesn't even have a tailpiece. I use foam (from heating tube isolation) to damp the afterlength vibration a bit on this instrument.

When I got my Clevinger (used) it had a piezo disk on the top below the E/B bridge foot with cardboard between piezo and top and a hard about 5mm in diameter and a bit less than 1mm thick disk of a hard material (looks like ferrit) that concentrates the pressure on a small part of the piezo disk and bends the piezo with varying pressure. After some experiments I came back to that idea, just put the whole thing into a wood enclosure also to raise the action a bit, since I angled my bridge (angled socket srewed onto the top) to get evenly distributed bridge string angles and this way the action came down.

The bridge foot is a good lace for a pickup, but only if you don't try to decouple vibration from the top to the pickup. There needs to be some more mass on both sides of the pickup or some frequency ranges might be attenuated too much.
And the signal from a piezo disk operating in pressure mode only is too low compared with other piezo transducers. So the bending of the piezo disk gives a much stronger signal.

Don't take anything I said for granted, but maybe remember it when you continue with your experiments.