Audio Gurus, I have a ?.

GPTourer · May 5, 2009, 02:47 PM

So after finally eliminating a hellish alternator whine that I've been dealing with for over a year now it occurred to me while I was playing around with one of my home entertainment setups:

Why is car audio still using RCAs?

Why not optical, or the digital plug (orange sherbert colored one) that home systems use? Would this not eliminate the noise problems that can enter the old school RCA connections? OR is it already here and I'm not buying upscale enough gear?

biggie5252 · May 5, 2009, 03:33 PM

I've never really come across noise due directly to Rcas, except maybe something you'd get at walmart that looks like it was made out of speaker wire. Even when routed down the same side of the car as power wire.

Almost always alternator whine is caused by a ground loop, if not faulty equipment.

Why does car audio not use digital as the norm? People don't care enough about the sound quality to pay for it. You would also have to have a DA converter in every amplifier, or make someone buy a stand alone converter.

There are plenty of upscale systems that use optical. Almost all dvd headunits have it. Alpine has a couple digital processors that take optical. Pioneer has/had a system that was completely digital back to the amps. It does exist and has since the late 80s/early 90s..

GPTourer · May 5, 2009, 03:39 PM

But what amps offer digital/optical inputs?

biggie5252 · May 5, 2009, 03:54 PM

None that I'm aware of, except the pioneer amps I mentioned (I'm almost positive they took a digital input). ODR or Optical Digital Reference was what the system was called. It consisted of a headunit, eq/dsp, and specific amps. Sony also had a similar system, but I don't know if it was digital.

Alpine does have a "theater" amp that takes optical in, but it's for a 5.1 system and not very high powered.

SRTRaceR04 · May 5, 2009, 07:29 PM

It's harder to run optical cable through the car.

Plus it's more expensive to design products that use it.

Aside from Dolby and any true surround sound audio is 2 channels so the necessity for digital audio is less.

SCEvol8 · May 5, 2009, 08:27 PM

Optical cables have one big inherrent flaw which will ALWAYS mean I will run RCA's in a car. Opticals are essentially a mirror running the entire length of the cable. If the cable gets a kink in it, that mirror inside can easily crack and distort sound (the cracked mirror isn't sending all the 1's and 0's to the headunit)....bad enough kink and no sound whatsoever. In addition, digital optical and digital coax are utilized to send large amounts of data to a headunit that can decode advanced codecs like Dolby Digital, DTS, TrueHD, and so on. iPod's and CD's do not come encoded with these codecs, thus no need for digital connections. There are options for running a seperate processor to utilize these formats but these are used for source material that utilizes said codecs (i.e. DVD movies). For the car, RCA's are fine....don't run them along the length of the car right alongside the power cable and you should be fine. I've run RCA's up the middle of the vehicle and power along the doors....been doing this for 10 years....never have I had engine noise. BTW....you can use ANY RCA cable as a digital coax....it does the same thing as the overpriced Monster Cable.....just as you can use ANY RCA as a subwoofer cable.