I don't mean to argue. I respect you. But it's the way you state things without any proof or links that kind of irritates me.
Does any of that help?
Actually? No. It's not who you say
you are, it's what you do
. Convincing is done by reasoning.
You are talking about someone (a German dipl-ing, an education which is held in the highest esteem anywhere in the world) making 'glaring errors' without saying what they are thereby disqualifying someone you don't know anything about who has a lot more to show for himself than you (again, no disrespect towards you). I only have an ing-degree in construction (which includes acoustics btw) so I'm disqualified in this matter anyway. But I do have 30 years experience in hifi and I do know how to listen.
The HF-rolloff you speak of is totally irrelevant. 1dB is the hearing threshold for discerning sound pressure-level differences at 1000Hz , human hearing reaches to 20kHz at a young age, 15kHz at best at my age with hardly any discernment at all as to loudness at that frequency. So 3.9dB difference at 22kHz is moot. Also does no-one state anywhere how much HF-roll-off is at 20kHz (which would be the point where it starts
to mean anything
) or how much at the extreme of my (or your) hearing.
Look at this:
See what the dynamic range of a healthy young person is at 20kHz (20dB) compared to 1kHz (130dB)? And I'm not even talking about the range of music (orchestral range in the graph).
This is how 'linear' our hearing is! Again, this is for a young person that hasn't ruined his hearing with his ipod, headphones, concerts etc.
This is how our absolute hearing threshold changes with the years.The Absolute Threshold of Hearing (ATH) is the volume level at which one can detect a particular sound 50% of the time. If one has a low absolute threshold, it means that he is able to detect small amounts of stimulation, and thus is more sensitive. If one has a high absolute threshold, then he requires more stimulation and thus is less sensitive.
The following are curves of the ATH for several age groups over frequency. Zwicker approximated these curves from experiments on a number of subjects:
When we speak of 20-20kHz in hifi, see how 1-dimensional this statement is? Because it is (ab)used by marketing to convince us to buy irrelevant expensive junk.
So when you speak of a high frequency roll-off of 3dB at 20kHz that is a 0-dimensional statement (not to say unsubstantiated or erroneous; it should be 3.9dB at 22kHz with no reference to how steep the roll-off is, 6? 12? 18? 24 dB/oct?).Edited by ]eep - 3/4/12 at 10:16am