I've built a new computer using an Aopen Cobra sound card.(Yes, it's
bottom of the line, but will serve temporarily.) Its output is 6.67 dB
lower than calibrated signals I play from a test CD. Also, line inputs
and audio signals from Winamp and Windows Media Player are too low
compared to my old Ensoniq PCI card.

All the mixer gains are at max. That's both mixers, the one with the
sound card (C-Media) and the one available through Control Panel/Sound
and Multimedia with W2000.

Also, if I try to record loud, heavily modulated FM signals at the Line
Input, the peaks are 6 dB below max. With the old sound card/mixer, I
would have to set one of the gains at 2/3 to prevent clipping.

I'm using the same amplified speakers as on the old computer.

Any ideas what might be reducing the gain?

Thanks,

Ray