In Reply to: How about well below 90 dB, Christine? posted by Jim Pearce on January 30, 2003 at 12:03:50:
have you ever measured the SPL of "ambient" noise in a quiet room? the figure is something like 30-40dB! even in my room (and i live in a quiet street) it can rise to 50-60dB with the fridge turned on (from a different room behind closed doors)let's say you are listening to music at rock concert like levels of 110dB. you are getting an overall S/N ratio of effectively 60-70dB at best.
in a worst case scenario (air-con, projector turned on) the S/N ratio may well drop to 30-40dB
this is all old news to mixing engineers which is why you will seldom hear content mixed at below 30-40dB (an exception is pat metheny who says he deliberately introduces content at -40-50dB for headphone listeners)
the S/N ratio on my old amp was only around 80dB. yet i have never heard the noise floor on this amp, even when cranking the volume all the way to 11 :-) (of course, there is noise if my ears are right next to the speakers, but not at normal listening position.)
so i very much doubt (if the player is performing to "spec") that the high frequency noise in sacd is detectable. of course, this is not to say that the noise may not induce artefacts (amplifier circuits oscillating, speaker colouration, phase shifts, whatever) that are detectable. but these are all equipment limitations.
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Follow Ups
- oh, by the way, even 90dB is actually a very *good* S/N ratio - Christine Tham 14:09:12 01/30/03 (5)
- Re: oh, by the way, even 90dB is actually a very *good* S/N ratio - Jim Pearce 14:22:36 01/30/03 (4)
- again, that is all as per spec and intentional ... - Christine Tham 14:33:51 01/30/03 (3)
- On the contrary, the Stereophile tests show that... - Jim Pearce 07:18:11 01/31/03 (2)
- no misunderstanding at all - Christine Tham 14:07:57 01/31/03 (0)
- Not exactly... - Frank 07:32:40 01/31/03 (0)