[LAU] Pro Audio? OT rant.

[Gene Heskett]

On Sunday 23 December 2012 14:03:18 Joe Hartley did opine:

> On Sun, Dec 23, 2012 at 5:45 AM, Fons Adriaensen 
<fons at linuxaudio.org>wrote:
> > > Given that most audio interfaces will perform better at 48 kHz than
> > > at 44.1
> 
> http://xkcd.com/285/
> 
> I've always had fine results running my Delta1010s at 44.1kHz, since I
> only do audio destined for CD and wanted to avoid the re-sampling.
> Why would running them at 48kHz make them perform better?

With all due respect for the opinions expressed here already, I would 
submit that there is more audible difference between them from the 
sharpness of the anti-aliasing brickwall filters, which can be designed 
with a pole or so less sharp in the filters when doing it for 48khz. That 
to me, would be the dominant difference IF the human ear also had a 
brickwall filter. Filters that sharp ring unavoidably.  You can sine wave 
sweep them and they look great, feed then a 2 kilohertz square wave with 
microsecond rise & fall times and go surfing on the edge ripples.

Sadly, it does not, or a least mine don't. At 78 yo, I still do not 
normally patronize an establishment that uses an ultrasonic, usually 44 
kilohertz, burglar alarm.  This is the one that detects the motion of the 
audio standing wave in the room from about a 10 watt driven piezo 
transducer on the ceiling when a body (or anything else, like a plate glass 
window flexing in the wind) is moving around in that room.  Many don't turn 
it off during the business day, just switching off the actual alarm klaxon.  
At my age, with Carhart notches 120 db deep in both of my ancient ears from 
wearing out several rifle barrels at the ranges, walking into such a 
business still makes my ears hurt, and will give me a splitting headache in 
5 to 10 minutes worth of it.

I rip my cd's to oggs at Q7 or better so as not to impart any more damage 
to an already damaged by a 16 bit 44.1khz digitization of what was likely 
an analog tape master running at 30 ips.  To my ears, a Q7 ogg is far 
preferable to _any_ bit rate of mp3.  The mp3 gives me tired ears that make 
me reach for the volume down button in just a few minutes.

This 44.1 vs 48 kilohertz argument seems to come up at 6 month intervals, 
and no doubt someone has invented a name for it, but nobody, not even me 
with 40 some years in broadcasting, can do no more than advise one to feed 
a 2 kilohertz square wave thru the system from end to end, looking at the 
output on an o-scope with at least a megahertz of bandwidth, and listening 
to the result.  Aliasing will be as obvious to your ears as the nose on 
your face if that square wave is varied in frequency by a hundred hertz. 
Under steady state drive your ears can hear that junk hundreds of times 
easier that if it was music, where the aliasing gets buried in the noise 
floor AND makes your ears 'tired' at the same time.

Cheers, Gene
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