Hey folks, working on my second bass build. This is an upright suitcase bass.
Does the fingerboard need to be radiused? The fingerboard I have now is flat red oak. My access to power tools is limited so if I can get away with a flat fingerboard I will.
I should also mention that I would like to play country/bluegrass/rockabilly/psychobilly if that makes a difference. I know little about upright bass playing technique and I am wondering if the radius on the fingerboard is essential to playing slap bass styles.
I have heard in the past that there are a few tricks that work such as sliding a small spring such as you would find in a ball point pen over the strings over the pup to be picked up. Haven't tried it but I don't like the idea of putting crap on the strings. Makes good armchair sense though.
I think the best route for me as far as amplification goes is to simply mic the current set up that I have. I may re-wire it to exclude the volume knob but I do like having control on the instrument. I have toyed with the idea of an active preamp like you linked and I may do that in the future. I think I may have to remake the bridge for a rod peizo if I decide to go that route.
The reason I used a small speaker for a mic is because I have recorded bass cabs and bass drums for years using a speaker wired to an XLR cable as the bass mic. The large diapharm picks up bass tones "better". The low E on a bass is only at around 41HZ, just barely above the limit for human perception. Thus my logic was that more surface area of a mic diapharm the better. That am I am cheap and am not excited about convincing my wife that I 'need' another microphone for such a limited function.
The speaker I am using for a mic is a very small 8ohm speaker I picked up in Korea. I had some DIY amp kits that had 8ohm outputs and had to look far and wide for a small speaker in that rating... most had no indication of their resistance. The paper cone is rather stiff and I think it would be better with a more sensitive diapharm... like vocal mics are often a clear thin plastic that seems to be more responsive. When I was in the Army I threw away dozens of the old rotrary phones and I took the vocal elements out first. The quality surprised me but they don't seem to be terribly responsive.
Another idea I have kicking around my skull is to cover the f-holes. My logic is that if they are covered the air pressure inside the box (suitcase) has no place to go and will exsert greater force or pressure on the speaker (microphone) element. I'd do this in a way that still has the f-hole form but no real function other than look pretty flicking cool.
Most foils aren't made of magnetic metals. And copper or aluminium foil (the most common types) wouldn't work with magnetic pickups in any case. It would have to be some ferrous metal like nickel, or some combination of the two. I'm guessing it would also sound pretty crappy.
Fellow member Turtlehead tried dipping peizos in a rubber compound that seemed to help things greatly. Take a look at his video here:
FWIW, I have never heard a peizo pickup that didn't benefit from going through even a simple basic onboard preamp. I personally think they're pretty harsh sounding when used on their own. And their bass response isn't that great to begin with, so you really need some EQ if you're using one with a bass.
Sticking a high impedance microphone inside the soundbox is definitely worth looking into. As long as you can control the feedback you should be good.
Nice, you need one addition though.
A cup holder in that top panel for your beer after you open it :D
Very nice job! What scale is it? Is it more like an upright scale (~41") or a bass guitar scale (30"-35")?