Ferrari Mailing List: Re: Need help with stereo in Ferrari

[Charles Perry (charles]

As a last detail, there is some use of balanced lines in car audio, but
it is strictly in proprietary systems and has no standardization. For
example, companies that use their own "network" cables to connect pieces
of their own equipment (such as Alpine's AI-Net or Clarion's CeNET)
often have balanced audio in the bundle, as well as control lines and
even video. However, there is no way to hook an Alpine head unit to a
Clarion processor using their respective balanced networks. For that,
you have to go back to RCA cables, giving up the related benefits.

-- charles
 

-----Original Message-----
From: Charles Perry [mailto:charles [at] carolina-sound.com] 
Sent: Sunday, March 08, 2009 11:42 AM
To: Charles Perry
Cc: The FerrariList
Subject: Re: [Ferrari] Need help with stereo in Ferrari

Just for everyone's future reference, the basic problem with all car
audio systems with respect to noise is that car audio is unbalanced by
design (meaning the music's electrical return path and ground are the
same conductor). A properly balanced system (most pro-audio equipment)
uses three conductors (positive, negative, ground), rather than an RCA
line's two conductors (positive, negative/ground).

The signifigance is that the "shield" of RCA wires is not actually a
shield since it is carrying the music signal. That is also why it is so
prone to picking up noise. This is why things like Monster Cable
interconnects are complete wastes of money. Extra layers of shielding
are, by definition, not shielding in car audio, nor in the vast majority
of home audio (anything with RCA connectors). 

This is also the hint of truth in Jeff's suggestion for using network
cable. Network cables are balanced and use their twist as part of a
noise rejection scheme (same as balanced pro-audio cables). This works
in networks due to the balanced electronics on both ends. Using network
cable for car audio will not give you the same benefits because the
electronics at both ends are unbalanced. It will still work, but no
better or worse than regular RCA cables.

In the 90's Rockford Fosgate tried to introduce balanced audio into the
car stereo world in their upper-end lines but it was expensive and
poorly understood and did not catch on.

My current favorite scheme is using fiber-optics as interconnects, but
this requires equipment that is designed for that, which is expensive.

-- charles