Help to get better indication on 20cent LED VUMeter

[dave_j_fan]

This is small circuit of a LED vu meter
design goals
:No extra power to be added
: no chips just basic parts

This running well on speaker wires
I have made 2 of this and shoots LEDS from center
Here is video

dont need ic or DC power ,
i have added a voltage doubler with 1N4148

The low LEd gets on at 3.2V and high at 8,4v
Problem :
it needs atleast 30% volume
need a ways to improve the voltage doubler
or shall i add a joule thief for getting better voltage