This does not hold true for final product designs though, where circuit layouts are such that crosstalk is reduced - of course it usually increases with frequency, but no 6dB/octave rule applies in the end, usually far from it. No consumer should therefore calculate and compare between specs - chances are you'll be a good 20dB out.
You should look at the actual product measurements on the testbench. Here's the first one I came across from Miller Audio Research lab tests archive:
Arcam CD37 CD Player: -105.01dB @ 20Hz, -104.94dB @ 53Hz, -105.02dB @ 118Hz, -105.87dB @ 472Hz, -106.48dB @ 1060Hz , -106.27dB @ 3360Hz, 105.40dB @ 5300Hz, -105.07dB @ 6000Hz, -103.76dB @ 8500Hz -103.19dB @ 9500Hz -102.53dB @ 10700Hz, -101.85dB @ 12000Hz, -100.35dB @ 15100Hz, -99.41dB @ 17000Hz, -97.74dB @ 20000Hz
Sorry if you took it personally, but so did I on behalf of those "fooled". Indeed, I am a friendly guy - forums dont transmit the nuances you want sometimes.

Just rigorous questioning - to benefit all of our knowledge, thats all.