Having your cake

PS Audio

New member
Joined
Apr 19, 2013
Messages
245
<!-- #thumb --> <p>For those of you following the trail of the Music Room construction and the installation of the Infinity Reference Standard loudspeakers, the latest chapter, <a href="http://youtu.be/rsroD57FZnA" target="_blank">part 6</a> is up and ready for viewing. *Part 7 will probably follow quickly as the IRS system is, as of this morning, setup in the room!</p>
<p>Yesterday’s post stirred some controversy and prompts me to both apologize and explain a little further. *I said that neither analog nor digital are continuous process and the apology comes because that happens to be more of a philosophical point of view from my part – as I look at the entire universe as an illusion of whole – but sharing my personal viewpoint on such things isn’t appropriate for this column. *Sorry.</p>
<p>Maybe a better way to put it is like this: if you consider analog continuous, then so too is digital. This is because within the bandwidth of the system’s agreed upon end points nothing ever stops – it is in fact continuous – certainly if we look at the output.</p>
<p>You can’t suggest that one is constantly moving while the other stops and starts if within the same limitations we see no discontinuity.</p>
<p>I think people get confused with this and get the idea that an analog system is doing something the digital system is not between the digital samples – in other words, if you’re imagining the digital system as starting and stopping to do its job and the analog system as continuous – then you believe the analog system is continuing to work between the tiny gaps of the digital system – and that’s not true.</p>
<p>If the analog system were, in fact, doing something between the digital gaps, then the analog system would have a much higher frequency response than it does, since we can all agree that those digital gaps are at a specific rate that we can calculate – and that rate is outside the bandwidth of the system.</p>
<p>Modern digital audio systems run at very high rates of speed. *Take our upcoming A/D converter we’ve been touching on. *That device runs at 6mHz – 6 million times a second. *Indeed, it is stopping and starting 6 million times a second – but you know that not from its results – only intellectually.</p>
<p>When the first digital audio systems hit the street they were running relatively slowly compared to today. *Those first systems struggled to deal with 20kHz – such that there had to be an incredibly steep filter in front of the ADC and at the output of the DAC – so steep (extreme) that at 22kHz there had to be essentially zero input or output. *Let me tell you, the kind of filter that gives you 100% signal at 20kHz and zero at 22kHz has a major impact on sound quality. *It was one of the reasons digital sounded so awful and even today many of the older CD’s were mastered using this brick wall filter.</p>
<p>Today’s ADC’s and DAC’s run so much faster and operate so differently that this filter has become almost trivial. *Our new ADC, for example, has a single gentle rolloff starting at 50kHz and it just takes its time getting low enough to not matter to the DSD converter running at 6 million times a second.</p>
<p>So you can’t put one system under a microscope and say “aha! It is stopping and starting and really not continuous – therefore we must be missing something when compared to our cherished continuous system that is capturing everything”. *That would be like having your cake and eating it.</p>
<center><a href="http://www.pstracks.com/pauls-posts/cake/10717/emailpopup/" onclick="email_popup(this.href); return false;" title="Forward to a friend and help us engage more readers" rel="nofollow"><img class="WP-EmailIcon" src="http://www.pstracks.com/wp-content/plugins/wp-email/images/email.gif" alt="email Having your cake" title="Having your cake" /></a>*<a href="http://www.pstracks.com/pauls-posts/cake/10717/emailpopup/" onclick="email_popup(this.href); return false;" title="Forward to a friend and help us engage more readers" rel="nofollow">Forward to a friend and help us engage more readers</a></center><br /><!-- // MAILCHIMP SUBSCRIBE CODE --><center><a href="http://eepurl.com/eSzBY">Get new and fresh stories like this each morning by joining the folks reading Paul's Posts. Click here </a></center>
<!-- MAILCHIMP SUBSCRIBE CODE // -->

[Source: http://www.pstracks.com/pauls-posts/cake/10717/]
 
Back
Top