charles@sunybcs.UUCP (06/26/84)
Since it is almost universally accepted that the sample rate of CDs is as low as possiple (or even too low already) I thought that you would like to know that at least one SONY CP player is playing in multi-plexed mono... cutting the sample rate in half. Krunching bits everywhere.
ark@rabbit.UUCP (Andrew Koenig) (06/29/84)
From Charles Pearson: "..at least one SONY CD player is playing in multiplexed mono... cutting the sample rate in half." Wrong again. The machine in question simply has a single D/A chip handling 88K samples/second rather than having two chips handling 44K samples/second each. The only ill effect is that the signal to one channel winds up 22.7 microseconds late. You can compensate for this by moving the speaker on that channel about 1/4 inch closer to your ears.
czp@houxa.UUCP (C.PODARAS) (07/02/84)
<chomp, chomp... maybe the monster will eat all of pearson's postings...> came in for a few last things at work, and decided to flip thru the net. gawd, what a mistake -- got pearson at his finest (?) again. oh well, a little humor for the road. charles, let me modify my previous flame. you are SUCH a douchebag. let's see... today i've read five of your postings, and ALL of them have contained "factual inaccuracies" (a nice term for bs). at least you're consistent... regarding your assertion of a sony cd player working in multiplexed mono that halves the sampling rate: the cdp101 utilizes a single d/a (unfortunately not a pearson labs 32-bit 10mhz chip -:) ), which converts one, then the other channel during a *single* sampling period. it does not halve the sampling rate. the player's problem, however, is that it doesn't delay one reconstructed output by the appropriate half-sampling- period delay, causing a relative delay of 11.34 us between channels. and as tests from pearson labs have shown, we all know that this just totally destroys any chance of appreciating such classics as beethoven's "square wave #9 in e minor", or little feat's "square waves don't fail me now" seriously, charles...thanks again for all the entertaining moments. have you considered branching out into videos? ciao, chuck podaras bellcore no more!
charles@sunybcs.UUCP (Charles E. Pearson) (07/02/84)
And would you care to annalyze the dispersion patters and
their differences of the two cases,
1) a normal CD (egads)
2) the multi-plexed mono with a speaker 1/4 inch closer to the ear.
The problems with earphones, (some people do use them, try the
STAX PRO LAMBDA for a good example).
How the same 'technoloy' could be used to give us a better sample
rate and/or a better resolution...
How the discontunity of any frequency will produce harmonic distortions
and the effect on the already problematic item.
What that does to immaging, if CDs had any to begin with.
How adjusting the balance control does not correct the problem.
Timing problems for the single (mono) reading head and how that may
effect channel separation... give you a hint, if the timing is off
it would wander back and forth between producing left/right signals
and producing right/left signals. This timing could be only off by
one part per billion for this effect to become apparent (unless
you have a truely flat immaging system.
Charles E. Pearson
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