I had the same problem when I first got my ply bass. I found
- tension makes a big difference. you have to find the right tension for your top to work properly - adjusters can help you find this. On my bass, I found a higher E string made for better volume, but only so far ... as you wind it up, eventually the top just chokes up. In the end, a heavier E string helped me get the best tension at the best string height.
- a lighter tailpiece and synthetic tailgut worked wonders for my pizz sound.
- playing in the corner of room facing the wall is a good way to hear yourself better, especially low end.
For me, the E string is a litmus test of a bass. When I go into a shop, if the E string doesn't sound straight away, I can't get interested in the bass.
I just hope my home-built bass has a nice E sound
