I’m wondering why many high end stereo A/D’s have relatively low analog input levels. Most pro consoles and gear are clipping at >24 dBu. However take a look at some sample A/D default input levels referenced to 0 dBFS:
- Cranesong HEDD +16 dBm (manual doesn’t state if this is max)
- Mytek AD +19 dBu
- Apogee Rosetta +20 dBu (can adjust to +24)
Why the “missing” headroom? Is it because full program material generally requires less headroom? This would assume all audio is pop music! What am I missing, something simple I am guessing.
Well, the Cranesong is completely adjustable, I’ve been able to set it to +16 dBu max through at least +24.
We have a Mytek 192 and it’s adjusted to +24 dBu so it must be adjustable though I forget how we did it!
The answer I think is a combination of incomplete documentation and a bit of ignorance or assumptions on the part of the designers. Many of them assume people will be using the converters for mixing with consoles that have VUs and the mixes will have a crest factor of 14 dB or less and that the users will want to “slam” the converter meters. A lot of assumptions, eh? A “perfect” A/D converter in my mind should be able to accept up to (or beyond) +24 dBu = 0 dBFS as a maximum and as a minimum have sufficient gain to accept +10 dBu = 0 dBFS, but I’m willing to accept +15 dBu = 0 dBFS, which should cover a wide range of circumstances.