[BC] Sibilant artifacts in Digital Radio

[Rich Wood <richwood@pobox.com>]

------ At 12:23 AM 12/3/2005, DANA PUOPOLO wrote: -------

>I have my XM home tuner connected up to my re-capped Advent 300 receiver.
>Speakers are Athena AS-B1, which are considered "Low high end" speakers. I can
>CLEARLY hear artifacts on just about everything bit rate reduced (especially
>male voices) - even many FM analog stations that use bit rate reduced audio
>sources.

The main artifact I hear is awful sibilants on both male and female 
voices. This is both AM and FM IBUZ. The other problem is on 
Classical music, especially stringed instruments. It appears that 
those stations that don't process heavily are the main victims. It's 
hard to tell the difference when the audio density is high. There's 
so much distortion that artifacts are the least of our worries on 
something like WPLJ, New York.

I have 2 NPR stations in HD in the area. Both exhibit the sibilant 
problem. It's not there in analog. If Stradivarius heard his violins 
sound this bad he'd become a musical terrorist. This distortion is 
profound enough to annoy a regular listener. The days of sitting in 
front of a stereo system to enjoy an Opera are going fast. One 
soprano (singer type) and your fine glassware is a thing of the past.

>Here's a (related) question - with all this bit rate reduced audio everywhere
>(radio, TV, DVD movies, etc.) that involves psychoacoustic masking, could our
>ears be getting 'better' at masking?

In this case my ears are better at masking because my hands are covering them.

>Could it be that my ears/brain have become better at masking then before
>because they're being 'exercised' more these days?

I think we all know that the brain adapts. Watch a low quality video 
and, after a few minutes, it becomes acceptable. You stop noticing it 
and concentrate on the content. I don't know that that's true of 
audio unless the content is so compelling that you'll endure any 
torture to listen. Remember that sound and smell are the senses that 
most recall past experiences. Another issue for remastering for 5.1.

Again, when I switch to a CD I get a blessedly clean sound, so I'm 
sure it's not the sound system.

Rich


Rich Wood
Rich Wood Multimedia
Phone: 413-303-9084
FAX: 413-480-0010