campbell@redsox.bsw.com (Larry Campbell) (03/18/90)
In article <sa0KhqO00Uh7M2R25C@andrew.cmu.edu> bas+@andrew.cmu.edu (Bruce Sherwood) writes:
-The analogy with audio is that a CD with frequency response out to 10
-MHz would not sound better than one with frequency response out to 20
-KHz, because the human ear can't hear the higher frequencies.
Speak for yourself. Perhaps the *average* human ear can't hear higher
than 20 KHz, but some can. I don't know what frequency they are, but
I can hear those "ultrasonic" sonar burglar alarms -- and they are loud
enough to be painful if I'm standing directly under the transducer.
But I know most people can't hear them.
CDs would have been nice if they had a decent high frequency rolloff; but if
I A/B an LP and a CD it is clear that the CD has cut off the higher
frequencies. So I get a choice -- ticks, pops, and rumble, or missing high
frequencies. Feh.
Anyone know if DAT will have a better high end than CDs (presumably this
depends almost entirely on its sampling rate)?
--
Larry Campbell The Boston Software Works, Inc.
campbell@redsox.bsw.com 120 Fulton Street
wjh12!redsox!campbell Boston, MA 02109sorka@ucscb.UCSC.EDU (Alan Waterman) (03/18/90)
I blieve DAT has 3 sampling rates, the highest being 48KHz. Not much better than a CD with 44.1 KHz. I'm totally loyal to CD's now. I have CD player and I no longer own LPs, but it would have been nice if the sampling rate could have been 88.2 KHz. I could have lived with a CD that has only 38 minutes of record time. The reduced high frequency phase shift would have been well worth it.
bakke@plains.UUCP (Jeffrey P. Bakke) (03/18/90)
In article <1554@redsox.bsw.com> campbell@redsox.bsw.com (Larry Campbell) writes: >In article <sa0KhqO00Uh7M2R25C@andrew.cmu.edu> bas+@andrew.cmu.edu (Bruce Sherwood) writes: >-The analogy with audio is that a CD with frequency response out to 10 >-MHz would not sound better than one with frequency response out to 20 >-KHz, because the human ear can't hear the higher frequencies. > >Speak for yourself. Perhaps the *average* human ear can't hear higher >than 20 KHz, but some can. I don't know what frequency they are, but >I can hear those "ultrasonic" sonar burglar alarms -- and they are loud >enough to be painful if I'm standing directly under the transducer. Although I personally can't hear higher frequencies as well as larry, I would buy audio products ;with higher frequency responses since the lower frequencies are often cleaner. A higher response will mean that the frequency response curve will die off at a higher level and then the lower frequencies will be more accurately reproduced. This is what I've been told anyway and what I believe to be true. Jeff Bakke bakke@plains.NoDak.edu
mpl@mit-caf.MIT.EDU (Mark Lubratt) (03/19/90)
In article <1554@redsox.bsw.com> campbell@redsox.bsw.com (Larry Campbell) writes: >CDs would have been nice if they had a decent high frequency rolloff; but if >I A/B an LP and a CD it is clear that the CD has cut off the higher >frequencies. Even if you can hear beyond normal hearing, the fact is that when listening to normal music, the energy in the lower frequencies mask out your perception of higher frequencies. That is why one can make an amplifier with a 15KHz rolloff and noone could tell except if they send pure tones through it. For normal broad band applications, the lower frequency energy will mask out what you would normally hear above 15KHz and you will never know it is missing. The other problem is that you aren't doing true A/B testing. You are biased. You can tell which is the CD and which is the LP just by the background hiss. -- Mark Lubratt, MIT Microsystems Technology Laboratories, mpl@caf.mit.edu
sorka@ucscb.UCSC.EDU (Alan Waterman) (03/20/90)
In article <4154@mit-caf.MIT.EDU> mpl@mit-caf.UUCP (Mark Lubratt) writes: >In article <1554@redsox.bsw.com> campbell@redsox.bsw.com (Larry Campbell) writes: >Even if you can hear beyond normal hearing, the fact is that when listening >to normal music, the energy in the lower frequencies mask out your perception >of higher frequencies. That is why one can make an amplifier with a 15KHz >rolloff and noone could tell except if they send pure tones through >it. For normal broad band applications, the lower frequency energy >will mask out what you would normally hear above 15KHz and you will >never know it is missing. Sorry, but you CAN hear the difference if you have my ears and you have a good pair of Bang and Olufsen headphones.
roc@sequent.UUCP (Ron Christian) (03/20/90)
Hey wait! Stop this! The CD vs. LP discussion has been going on for literally years in rec.audio. I haven't looked, but I'm sure it's still going on. Why don't you join it there? This thread no longer applys to rec.video, comp.std.internat, or comp.graphics, and is questionable in sci.electronics. What's next? Abortion? Save the whales? Ron
rdh@sli.com (Robert D. Houk) (03/20/90)
In article <4154@mit-caf.MIT.EDU> mpl@mit-caf.MIT.EDU (Mark Lubratt) writes: In article <1554@redsox.bsw.com> campbell@redsox.bsw.com (Larry Campbell) writes: >CDs would have been nice if they had a decent high frequency rolloff; but if >I A/B an LP and a CD it is clear that the CD has cut off the higher >frequencies. Even if you can hear beyond normal hearing, the fact is that when listening to normal music, the energy in the lower frequencies mask out your perception of higher frequencies. That is why one can make an amplifier with a 15KHz rolloff and noone could tell except if they send pure tones through it. For normal broad band applications, the lower frequency energy will mask out what you would normally hear above 15KHz and you will never know it is missing. So, you've never listened to cymbols? snare drums? organ? trumpets? All have significant information ("harmonics") well past 15KHz, well past 20KHz for that matter. No, not everyone can hear them. Not everyone can "hear" terminals (15Khz flyback) either - but personally I find them rather an- noying. Chopping off music at 20KHz (CDs) or even 15KHz (FM, and de facto much prerecored music) doesn't deter you from identifying what instrument is playing, any more than NTSC TV pictures deters you from identifying what actor/ess is playing, but higher resolution is distinguishable, more enjoyable (and/or realistic), and addicting to boot. -RDH -- "If you build a system RDH@SLI.COM | uunet!sli!rdh that even a fool could use, Robert D. Houk then only a fool Software Leverage, Inc. would want to use your system." 485 Massachusetts Avenue -Somebody-r-Other's Law Arlington, Mass. 02174 Office (617) 648-1414
amanda@mermaid.intercon.com (Amanda Walker) (03/20/90)
In article <7080@ucdavis.ucdavis.edu>, sorka@ucscb.UCSC.EDU (Alan Waterman) writes: > > In article <4154@mit-caf.MIT.EDU> mpl@mit-caf.UUCP (Mark Lubratt) writes: > >In article <1554@redsox.bsw.com> campbell@redsox.bsw.com > >(Larry Campbell) writes: > >[...] For normal broad band applications, the lower frequency energy > >will mask out what you would normally hear above 15KHz and you will > >never know it is missing. > > Sorry, but you CAN hear the difference if you have my ears and you have > a good pair of Bang and Olufsen headphones. It also depends on the spectrum of the material you are listening to, and probably a whole 'nother handful of factors. For example, I have good hearing up to about 22KHz, and spotty up to about 24KHz (with a couple of spikes of tinnitus down below 8K :-)). For pop music, or music just kind of playing in my living room, I'm quite happy with my cheapo receiver that only goes up to about 15KHz. For classical stuff or uncompressed folk music, I like my nice Sony headphones that go up to at least 22KHz. The same is true for video. For watching CNN, or most network TV, an NTSC monitor works pretty nicely, even if I can see the interlace flicker, as long as the ambient lighting isn't flourescent. For movies, or for things like weather maps or financial charts, I'd love to be able to see them in HDTV. -- Amanda Walker InterCon Systems Corporation "Many of the truths we cling to depend greatly upon our own point of view." --Obi-Wan Kenobi in "Return of the Jedi"
bas+@andrew.cmu.edu (Bruce Sherwood) (03/21/90)
Sigh. I was afraid of this. I'll restate it: Maybe someone cares about CDs going above 20 KHz. So to make the point I was attempting to make let's say that no one cares about CD audio going above 100 KHz, or if that isn't enough, 1 MHz, ok? My point is that there IS a physiological limit. Beyond a certain point it isn't even a tradeoff between quality and cost: higher fidelity won't make ANY difference because of limitations of human perception. Bruce Sherwood
ghl@tybalt.caltech.edu (Gwoho H. Liu) (03/22/90)
sorka@ucscb.UCSC.EDU (Alan Waterman) writes: >I blieve DAT has 3 sampling rates, the highest being 48KHz. Not much better >than a CD with 44.1 KHz. I'm totally loyal to CD's now. I have CD player >and I no longer own LPs, but it would have been nice if the sampling rate >could have been 88.2 KHz. I could have lived with a CD that has only 38 >minutes of record time. The reduced high frequency phase shift would have >been well worth it. can you hear phase shift at high frequencies ( or any frequencies at all)? the wavelength of 10k is about an inch. if your ear is about 1/2 inch closer to one speaker than the other ear is to the other speaker, then there will be a relative phase shift of 180 degrees. besides, if your head is much bigger than 1/2 inch, i dont think you can hear the difference anyway. but some people are amazing and can hear amazing things. cd are very good, and the sound nice, but their main advantage is not that they sound nice. the main advantage is convienience. they do not need to be rewound as tapes do. they are smaller than records, and most cheep record players can not repeat or skip around without my using my hand to move the needle.
ma299ai@sdcc6.ucsd.edu (Jan Bielawski) (03/22/90)
In article <7072@ucdavis.ucdavis.edu> sorka@ucscb.UCSC.EDU (Alan Waterman) writes:
<
<I'm totally loyal to CD's now. I have CD player
<and I no longer own LPs, but it would have been nice if the sampling rate
<could have been 88.2 KHz. I could have lived with a CD that has only 38
<minutes of record time. The reduced high frequency phase shift would have
<been well worth it.
There are no phase shifts if oversampling is used both during
the recording and during the playback.
Jan Bielawski Internet: jbielawski@ucsd.edu
Bitnet: jbielawski@ucsd.bitnet
Dept. of Math UUCP: jbielawski@ucsd.uucp
UCSD ( {ucsd,sdcsvax}!{igrad1,sdcc6}!ma299ai )