Radio Man, try a 10uf non-polarized cap on your tweeter, to smooth out
frequency response. If you have a woofer coil, bypass it as well. Didn't see
what type of receiver you're using, but most modern solid-state units
emphasize bass-n-midrange as a means of fighting static crashes-n-other
hi-frequency rfi content. Utilizing outboard amplification, via tape output,
will produce acceptable hi-fi quality sonics. Got a cap modded ICOM R-75 which
now replicates that 70's-era Pioneer midrange-centric fidelity, when driven
through direct-coupled Marantz MR-235 amplification. Through the stock speaker,
though, audio is still pedestrian at best.