Pickup placement on (semi)hollowbody

[ma_headphone]

In the last days I've built a 4 string fretless cigar-box guitar and since I think it turned out fairly well as a first project, I started building a 3 string fretless short scale cigar box bass as well! I ordered two cheap rail-pickups and I'm planning to install them, one on each instrument.

Being these instruments (semi?) hollow body, how shall I install the pickups on them? Shall they be attached to the top soundboard plate and be free to vibrate with it (it vibrates a lot and for very long)? or shall they be anchored to the solid "backbone" which is connected to the the neck? Or to both? I saw a video where a guy was attaching the pickup to the soundboard and putting rubber between it and the "backbone" to dampen the vibrations.

Please note that I don't think I'll ever play these instruments through amplification, it will be either acoustic or studio/headphone use, so feedback is not a concern.

As we're at it, I saw that the semi-hollow bass from Paul McCartney had no holes. Shall I carve holes in the soundboard of the bass I'm building, how is their presence going to affect the sound coming from the pickups?

 

[Bizman62]

All options are usable and have been used in the past. There's surface mounted pickups, there's those that require either a ring or a scratchplate and there's those that are mounted to the body. If the top vibrates a lot, I'd be tempted to mount the pickup to the backbone and leave enough clearance for the opening on the top so that it won't resonate against the pickup. Then again a surface mounted pickup might produce an interesting sound effect with the vibrations... You don't know until you've tried!

The reason for the Hofner bass not having sound holes may be an attempt to reduce feedback. Back in the day guitarists used to stuff their hollow body guitars with foam rubber to reduce feedback, modern pickups may not be as prone to it because of wax potting or some other magnetic magic.