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1.0 or 1.5 m digital interconnect, does it matter?

Hi folks, in theory 1.5 m length for S/PDIF should be better than shorter lengths. But in real live does it matter much if the cable length is 1.5 m instead of 1.0 m? I mean, does one hear clear sonic differences between the two lengths? Does one for example hear a grittier sound with the 1.0 m compared to the 1.5 m cable?

Chris
dazzdax

Showing 3 responses by audioengr

audioengr
3,282 posts
 
Sogood51 - you missed the point entirely. You should read the WHOLE white-paper:

http://www.positive-feedback.com/Issue14/spdif.htm

There are "sweet-spots" in length for S/PDIF because of the way transports are made. I sell 1m cables to customers that have my modded Transports. This enables them to use the shorter cable. Extremely short, such as 9 inches is also a "sweet-spot". Stock Transports can sound better with the 1.5m cable, depending on the cable and the Transport. Most of them do, but there are exceptions. If the cable is not 75 ohms or is very lossy, then it may sound the same in all lengths....

Steve N.
Empirical Audio
Manufacturer
audioengr
3,282 posts
 
Rlwainwright - serious whack job eh? It just so happens that an independent Audio magazine in Canada did a series of double-blind tests and published the results in their mag based on the claims in my white-paper. The results matched my conclusions.

The editor of this magazine came into my suite at CES last year and gave me a copy of this article. It was his hope to debunk my article, but instead he became a believer. This is pure engineering analysis, not snake oil. Read the paper.

And BTW, I have lots of inferior digital cables from other manufacturers than sound crappy in all lengths in all systems. Even in 1.5m, they dont deliver the magic. Proves nothing.

Steve N.
Empirical Audio
audioengr
3,282 posts
 
Whether you can hear a degradation depends on how well the cables are terminated and whether the connectors and cable is 75 ohms etc.. If everything is matched perfectly, then the cable length is less of an issue. It is when there are reflections on the cable that the length comes into play. Most S/PDIF outputs are not 75 ohms, but most S/PDIF inputs are 75 ohms. The cables and connectors vary a lot.

The comparison to an analog cable is not a valid one. Transmission-line effects on an analog cable are usually inconsequential or have small impact. The same effects on a digital cable can make a big difference in jitter.

The degradation is a lot like the sound of jitter. It is high-frequency noise layered on the music that can be described as echoes, halos or sibilance. I do a demonstration at CES each year and most people dont hear anything until the jitter is gone. Then they realize what they have been missing and what the noise is that they have grown accustomed to listening to.

Steve N.
Empirical Audio
Manufacturer
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