Noise Floors

[fayettec]

I have a Phonic FireFly 808 (Firewire) that since I've received I have question its quality. There was a driver update that seem to fix all the problems I have had. Armed with info and inspiration from this site I decided to set it up for 192k/24b recording. Using Sonar 8 I decided to see what the noise floor was no mic no gain. I came up with about -72Db - -68Db Peak (not RMS) is that good? I thought it was high so I tried a E-MU 1616 but it was about -42DB. That seems crazy. What do you all think?

[fayettec]

I just tried seting meter option to rms and the phonic firefly dose not register (-90DB scale) unless I crank the mic pre amp. the e-mu 1616 was -54ish

[fayettec]

I just found if I switched to 48K/24b Peak Noise dropped to -84DB when I went to 48k/16 I got -86DB peak. By Boosting the recored signal by 18 DB RMS came out to be about
-76DB/-80DB Add the 18DB Gain that is then -94/-98DB RMS

[fayettec]

one last note. the firefly has adat. I have a Yamaha O1v with adat. Using ADAT set to 48k/16 my peak noise floor is below -90DB (limit of sonar meters. Even with an MXL 991 mic my noise floor with the gain set for a loud voise to clip is near -90DB. Guess I know How I should record now. Any Opinions?

[garageband]

Anything from -101 to -75dB (preamps potted down) is fine. As a general matter, this really isn't something to be too gripped about.