RCA vs OPTICAl vs COAXIL

[vanillavato]

<font color='#000000'>Is there much of a difference in normal rca plug hookups and optical and coaxil that you can hear? Can Standard RCA handle the 20-20,000 Hz signals properly and does it have distortion? Thanks.</font>

 

[Guest]

<font color='#000000'>I don’t consider myself an “audio expert” just an average Joe. I have a Denon 3803, DCM Time Window 1A’s and a Mits DD8020 DVD.

When I originally hooked up the DVD to the receiver I used a RS gold plated audio cable to the coax. I simply had nothing else and wanted to hear what the new receiver sounded like; it sounded great!

After talking with some guys at work I was convinced that I should run a fiber optic cable. So I purchased a $30 Monster Cable fiber optic interconnect. I plugged that bad boy in and listened to the same DVD again (Twister) in DTS.

My 3803 gives me the ability to switch from coax to optic and I did that to compare the audio. I heard no difference whatsoever.

Yes, I’m using 16 awg Monster “high resolution” cable with the “magnetic flux tube” (what is that a wave guide?) to the speakers. Both ends of the speaker cable are terminated in Monster Cable gold plated banana plugs. So I figure I should have heard a difference. The main speaker runs are about 10 ft. It sounded exactly the same, sorry.

I’d say get what you think looks best because (IMHO) the difference in looks is about all the difference you will ge</font>

 

[audioengr]

<font color='#000000'>Your question is not very clear, but I will try to demistify this for you.

Analog interconnects are generally RCA connectors, but the cable can be a coaxial, twinaxial (twisted pair in a shield), or simply an unshielded twisted-pair. &nbsp;All of these will have wide enough bandwidth to handle the audio range. &nbsp;However, at the high-frequencies, poorly designed cables can cause their own noise and phase-shift, and this is the case with most cheap interconnects. &nbsp;In order to have a really good-sounding interconnect, one needs low capacitance and good metallurgy in the wires.

Digital connections can be made with either RCA, BNC or optical (Toslink) terminations. &nbsp; Digital wired cables have the additional requirement that they must have 75 ohms characteristic impedance. &nbsp;The connectors should also be 75 ohms, but this is not the case with RCA connectors, only BNC connectors. &nbsp;You will find BNC's on higher-priced equipment and lots of test gear. The digital cable can be a coaxial or twinaxial cable, but generally it is difficult to build a 75 ohm unshielded cable, so a simple twisted-pair will usually not cut it. &nbsp;In general, people have found that the best sound quality comes from using the wired digital connection, not the Toslink optical.</font>

 

[gene]

<font color='#000000'>I am also a little confused by the original question.

However, in general, the differences between using coax vs optical cables for transmission of PCM, DD/DTS, etc are subtle at best.  If your cable run is short (1-2meters), coax is usually preferable as it allows for a more durable connection.  If your runs are long (&gt;2meters), and you are routing all of your cables in close proximity, optical connections may work better in your situation to minimize EMI/RFI problems.  

Please review some of our cable articles and buying guidelines at:
Cable Budget Guidelines

Connection Tips 101

Cable Principles

Bulletproofing your System


Despite the myths and claims propogated on the internet by many cable vendors, cables cannot cause non linear distortions.  

In general, what is important with:
Analog Interconnects: low capacitance and good shielding.
Speaker Cables: low DCR and inductance.
Video cables good shielding, low capacitance, and compatible 75ohm connectors certainly can't hurt.

[edited links]</font>

 

[audioengr]

<font color='#000000'><table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Quote </td></tr><tr><td id="QUOTE">Analog Interconnects: low capacitance and good shielding.
Speaker Cables: low DCR and inductance.
Video cables good shielding, low capacitance, and compatible 75ohm connectors certainly can't hurt.</td></tr></table>

I agree 100% with all of these, with the exception of the shielding on IC's &nbsp;I have not found this to be necessary 99% of the time. &nbsp;The others address most of the first-order effects.

As for Toslink versus wired SP/DIF, there is a lot of anecdotal evidence that different lengths have different sound quality, indicating poorly designed optical stages in some consumer equipment. &nbsp;There is also the obvious disadvantage of the additional analog to optical and optical to analog conversions in the digital signal path, which tend to add jitter. &nbsp;This may be offset by the fact that the optical cable does not add much jitter, but good wired cables can also add very little jitter.</font>

 

[gene]

<font color='#000000'>Audioeng;

Points well taken. &nbsp;However, for the most part I feel shielded interconnects, providing that they are low capacitance, will have more benefit than not in most peoples systems. &nbsp;Given the wiring mess of most peoples home theater systems, mine included, shielding will certainly help eliminate potential problems. &nbsp;I also try as best as I can to isolate power wires from speaker wires, or at least orient them orthogonally from each other, and keep my video/digital interconnects as far away from the rest of the chain as possible. &nbsp;I truly believe &nbsp;Shielded video interconnects are a must, especially for HDTV.

As for digitial audio interconnects coax/toslink, &nbsp;I personally prefer coax for short runs as I also quesiton added jitter due to poor optical converison circuitry. &nbsp;However, the digital audio equipment usually has buffering stages and/or reclocks the signal to compenstate.</font>

 

[audioengr]

<font color='#000000'>Regarding reclocking: I have found that a lot of equipment that claims to reclock the data at the receiving end actually does a rather poor job of this. &nbsp;For most of these, the sound improves dramatically with a low-loss SP/DIF cable. &nbsp;If the data were truly being reclocked, then this would not make any difference.

Frankly, I believe that only the $16K Meridians and the portable CDP's that have &quot;shock-proof&quot; buffering actually buffer the data enough that a low-loss cable will not make any difference. &nbsp;Just based on my experience.</font>

 

[gman]

<font color='#000000'>Vanilla:

IMHO, regarding digital cables, either coax. or fiber optic, buy whatever you want, just make sure the cable has decent build quality, i.e. good end connections. &nbsp;There is absolutely no need to buy expensive digital cables - complete waste of hard earned cash. &nbsp;If you choose to use coax., just make sure in addition to good end connections the cable has good shielding.

Also, IMHO, the ongoing debate regarding what digital cables to use, beit coax. or fiber, 'high-end' or 'low-end', should not exist. &nbsp;Digital = transmission of data in the form 1's and 0's, that's it, end of discussion! &nbsp;That is why digital cables cannot be 'colored' or have a certain level of 'warmth'. &nbsp;When your local BestBuy sales guy tells you that a $100 Monster fiber cable is going to sound better than a $20 'low-end' fiber cable, tell him to kindly find another line of work, because he doesn't know WTF he is talking about. &nbsp;EMI/RFI can influence coax. cables and introduce errors (although you probably wouldn't recognize them anyway), and thus it would seem fiber cables are the more 'reliable' choice as we're talking about data transmission via light pulses.
My 2c.

gman</font>