Optical or Coaxial digital cables, how are they different?

Question

Optical or Coaxial digital cables, how are they different?

Answer 1

I have used both and found no differnce in sound

Answer 2

For home theater use.They both provide essentially the same result.

Optical is recognizable by its squarish connectors and it uses light to transmit the digital data and Coax looks like a single RCA cable the data is transmitted along a copper wire. Coax will be much more durable.

Answer 3

I think Dave is a bit two harsh re coax.

They are two forms of the same thing: S/PDIF (Sony/Phillips Digital Interconnect Format). Under most circumstances the two are interchangable.

Wikipedia (first link) states: "there are no differences in the signals transmitted over optical or coaxial S/PDIF connectors—both carry exactly the same information. Selection of one over the other rests mainly on the availability of appropriate connectors on the chosen equipment and the preference and convenience of the user. Connections longer than 6 meters or so, or those requiring tight bends, should use coaxial cable, since the high light signal attenuation of TOSLINK cables limits its effective range. On the other hand, TOSLINK cables are not susceptible to ground loops and RF interference like coaxial cables."

Both are digital audio connections. Coax uses a 75 ohm coaxial wire to conduct an electrical digital signal. Optical uses one or more fine plastic or glass fibres to carry a signal in the form of a series of light pulses. Both are considered superior to analog. Both allow connection of multichannel (5.1) sound.

Optical is prone to jitter (timing errors) and is somewhat more demanding re installation since the cables can't be bent at sharp angles. On the other hand it can be a smaller diameter connector which saves space under some circumstances. Even price is not a big differentiator since quality cables of both types cost about the same.

There are other arguments to be made about the advantages and disadvantages of the circuitry to support the two formats, but for use as a connection mechanism in the home theatre or audio sphere they are pretty much interchangable.

See the last two links for further discussion.

EDIT

Mike... claims that optical is better because of constant bandwidth over greater distance (and immunity from RF/EMI). Bandwidth is only one factor and is useless if the signal is unreadable. I also note he doesn't cite any references. The bottom line is the two cables at any reasonable length in home theatre application give essentially identical results.

Answer 4

While some may claim to be able to here the differences in digital cables I seriously doubt that most  systems would be able  to tell the differences between a optical cable and a coax digital interconnect.The cable you choose should have decent build quality and make a good physical connection Optical cables are less prone to RF interference but a well sheilded coax should have no trouble either.

Technically fiber-optic cable offers considerable advantages over standard coaxial cables. The most obvious distinction between the two is the great bandwidth-distance capacity of fibers. The high-frequency capacity of coaxial cables decreases rapidly with increased length, but the bandwidth of a fiber-optic system will remain constant with length. Fiber-optics remains constant for a bandwidth over a distance of 4,000 ft, while three different sizes of coaxial cable rapidly drop in less than half the distance.

For RG-179 coax, a 1,024 × 1,024 signal is limited to 50 ft; RG-59 rolls off 3 dB at 170 ft. Larger, bulkier cables such as RG-11 can reach up to 250 ft, but are impractical to install, (who runs these distances in home theather anyway), since three such cables are required for RGB color. Fiber-optic cable, on the other hand, allows transmission of more than 60 MHz video clock over a mile, and 20 MHz over 2½ miles, with no repeaters or equalizers.

Noise interference is another important area in which performance differs greatly. One major item of note that may cause issue is coaxial cables are susceptible to induced interference (EMI/RFI) from such noise generators as fluorescent lights, computers, power cables, industrial equipment,(motors etc), and even other communications cables. Cable frequency equalization further aggravates this noise problem. Fiber-optic cable is, in contrast, immune to all forms of EMI, RFI, and crosstalk.

Answer 5

Optical uses fiber optic cables to transmit a signal. There are less losses and higher quality sound available through optic. If you want to use one format, it would be optic, as it provides the best quality sound

Coaxial is lossier and less flexible. It still transmits a digital signal, but it's not as good as optical.