Double bass with little mark III

@fdeck would know how his HPF3 would get you there. Maybe he'll stop by.

 

You'll have better luck posting this question in the "Double Bass" forums.

 

The Copper Head is a piezo based pickup. I believe it would benefit from an input impedance of at least 1 Mohm. The LMIII input impedance is 500Kohms. It's not terribly low, but also not ideal. I would suggest using a device like an Empress ParaEQ which has a 1 Mohm input impedance. This will buffer the piezo, which will smooth it's natural frequency response. Piezos tend to be a bit quaky sounding if the load impedance is too low. Additionally, you can use the ParaEQ to tune out feedback and resonance modes so the bass sounds more natural. The louder you intend to play, the more relevant the versatile EQ will be.

ParaEq

Another thing you can consider is use amp placement to limit the amount of acoustic energy that is fed into the basses body. I like to elevate the amp to slightly above my waste and place it directly behind me. The bass should be angled a bit so that big flat back is not aimed directly at the speaker. In my experience you can play a lot louder with this approach before the amp and bass will begin to feedback. However, some players really don't like elevating the amp, so try it and decide for yourself.

You may find that wedging a towel between the tail piece and the bass's body helps with undesired resonance.

 

Thanks! Much as I love the HPF, I always suggest giving it a try without one. There's no reason to carry extra gear if you don't need it. I get an employee discount, so of course I use one.

Many amps designed for electric bass are "voiced," meaning that they do not have flat frequency response when the EQ knobs are centered. The built-in voicing is not necessarily the best starting point for upright bass, so it's worth playing with those knobs, and not being afraid of rather extreme settings. For instance, turning the Bass knob down quite a lot will tend to flatten most amps. Everything, including "flat" response, is a starting point, not an absolute.

Amp placement is important. Getting it further away from you will make it sound more natural by reducing feedback. Even amounts of feedback below the threshold of audible howling, affect your sound. It will also change how you listen to yourself in relation to the band.

Every bass amplifies and feeds back differently, so you might find that your bass has a good side and a bad side, affecting the best location of your speaker. For instance, I put my amp on the floor, others on a chair, and so forth.

If you're switching from electric bass, it will take some getting used to the different dynamics, both for you and for the band. They will have to be more mindful of the fact that you're now playing an acoustic instrument. Even if it's amplified, it's still acoustic because the bass is interacting with its own sound.