Digital Coaxial vs Optical Toslink

[cmdrdredd]

Originally posted by: spidey07
Oh well, just trying to present information so people are aware and informed. Keep up with your "it's the same", "it's just digital" beliefs.

I never said it's just digital...

What I'm saying is when it comes out of the speakers it is the same information, same signal, same quality. One may be lossy, but you're still getting the full 640kbps soundtrack.

 

[dainthomas]

DTS sounds just fine to me coming from my A2 through a toslink cable. Maybe I'll spend a couple hundred bucks more for a player with coax out so I can tell the difference on a spectrum analyzer. :roll:

 

[biggestmuff]

Originally posted by: spidey07

Originally posted by: cmdrdredd

Originally posted by: spidey07
You're receiver wouldn't tell you. YOU DO NOT GET THE SAME SIGNAL. I don't know how to get this through peoples heads. Hook up a spectrum analyzer and measure the jitter of a toslink transmitter and cable. You wouldn't like the results.

Yes I can hear a difference. You can also measure this difference with test equipment.

-edit-
what I mean is you receive the frames, but those frames have clocking differences in them (jitter). This is measurable with toslink, not measurable with coax.

You mean to tell me that your ears are so tuned that you can actually tell what hookup method is used? You're full of shit.

No, just can tell a difference between the two. Tell me then why don't studios use toslink?

cmdrdredd, spidey07 has a history of posting in these threads. He has claimed there's an audible difference in past threads, but has since backed down from those statements. He has also admitted that he has never tested the two connections together, back-to-back under ideal circumstances.

spidey07, studios don't use toslink because it is not a professional level transport. Studios still use high quality, balanced, analog connectivity and AES/EBU for most digital connectivity between processing devices. For transporting files from the DAWs to the server farms, 100Base-T COTS LAN equipment is used with a move towards GIG-E. And with all of that high technology, almost every studio still uses MIDI in some way even though, by today's standards, its speed of 31.5 kBaud is relatively low.

 

[montypythizzle]

Originally posted by: biggestmuff

Originally posted by: spidey07

Originally posted by: cmdrdredd

Originally posted by: spidey07
You're receiver wouldn't tell you. YOU DO NOT GET THE SAME SIGNAL. I don't know how to get this through peoples heads. Hook up a spectrum analyzer and measure the jitter of a toslink transmitter and cable. You wouldn't like the results.

Yes I can hear a difference. You can also measure this difference with test equipment.

-edit-
what I mean is you receive the frames, but those frames have clocking differences in them (jitter). This is measurable with toslink, not measurable with coax.

You mean to tell me that your ears are so tuned that you can actually tell what hookup method is used? You're full of shit.

No, just can tell a difference between the two. Tell me then why don't studios use toslink?

cmdrdredd, spidey07 has a history of posting in these threads. He has claimed there's an audible difference in past threads, but has since backed down from those statements. He has also admitted that he has never tested the two connections together, back-to-back under ideal circumstances.

spidey07, studios don't use toslink because it is not a professional level transport. Studios still use high quality, balanced, analog connectivity and AES/EBU for most digital connectivity between processing devices. For transporting files from the DAWs to the server farms, 100Base-T COTS LAN equipment is used with a move towards GIG-E. And with all of that high technology, almost every studio still uses MIDI in some way even though, by today's standards, its speed of 31.5 kBaud is relatively low.

:thumbsup:

 

[zinfamous]

Originally posted by: spidey07
Oh well, just trying to present information so people are aware and informed. Keep up with your "it's the same", "it's just digital" beliefs.

well, if you'd ever provide links that support your information......

 

[TastesLikeChicken]

There are valid arguments for both sides of this issue. Theoretically, digital coax does have some advantages over TOS transmission since there's no digital to optical conversion. It also has some drawbacks, such as the potential for ground-loops.

However, the bandwdith of both is so large and so little is used in comparison during transmission it's like arguing whether a 3000 horsepower jet engine is better than a 2000 horsepower jet engine for doing a steady 40 mph.

As far as jitter, that doesn't come into play in digital transmission. Jitter is only an issue during a digital to analogue conversion process.

In regards to audible differences, no blind tests have ever been able to establish that people can hear a difference between the two, even when people who claim to be able to detect a difference are used. The only real difference is apparent when the people tested know what type of transmission mode is being used in advance, which would imply that any audible difference is psychological in nature and not truly perceptive.

 

[nguyendot1]

For all intensive purposes, and for the audience this thread is pointed at, optical and coaxial are the same.

Remember a digital coaxial cable must maintain a 75 ohm impedance throughout its run. You can't bend it much either, much like an optical cable or it will go out of impedance.

As for only applying to digital/analog conversion, unless you have some newfangled pure digital speakers, your amp/receiver will convert the signal from digital to analog.

Either way, whichever you use will sound good. I use both, ,don't really care if there's a .01% difference, it just sounds good.

 

[PurdueRy]

Originally posted by: nguyendot1
For all intensive purposes, and for the audience this thread is pointed at, optical and coaxial are the same.

Remember a digital coaxial cable must maintain a 75 ohm impedance throughout its run. You can't bend it much either, much like an optical cable or it will go out of impedance.

As for only applying to digital/analog conversion, unless you have some newfangled pure digital speakers, your amp/receiver will convert the signal from digital to analog.

Either way, whichever you use will sound good. I use both, ,don't really care if there's a .01% difference, it just sounds good.

pure....digital.....speakers.....

Does....not....compute....


And you can bend digital coax all you want and it will work just fine(provided you don't break the conductor).

 

[YOyoYOhowsDAjello]

Originally posted by: PurdueRy

Originally posted by: nguyendot1
For all intensive purposes, and for the audience this thread is pointed at, optical and coaxial are the same.

Remember a digital coaxial cable must maintain a 75 ohm impedance throughout its run. You can't bend it much either, much like an optical cable or it will go out of impedance.

As for only applying to digital/analog conversion, unless you have some newfangled pure digital speakers, your amp/receiver will convert the signal from digital to analog.

Either way, whichever you use will sound good. I use both, ,don't really care if there's a .01% difference, it just sounds good.

pure....digital.....speakers.....

Does....not....compute

I stopped paying attention at "intensive purposes"

 

[PurdueRy]

Originally posted by: YOyoYOhowsDAjello

Originally posted by: PurdueRy

Originally posted by: nguyendot1
For all intensive purposes, and for the audience this thread is pointed at, optical and coaxial are the same.

Remember a digital coaxial cable must maintain a 75 ohm impedance throughout its run. You can't bend it much either, much like an optical cable or it will go out of impedance.

As for only applying to digital/analog conversion, unless you have some newfangled pure digital speakers, your amp/receiver will convert the signal from digital to analog.

Either way, whichever you use will sound good. I use both, ,don't really care if there's a .01% difference, it just sounds good.

pure....digital.....speakers.....

Does....not....compute

I stopped paying attention at "intensive purposes"

I wish I would have.

 

[spidey07]

Originally posted by: PurdueRy


And you can bend digital coax all you want and it will work just fine(provided you don't break the conductor).

There is a minimum bend radius with coax as well. All cables have a minimum bend radius to keep their properties.

 

[PurdueRy]

Originally posted by: spidey07

Originally posted by: PurdueRy


And you can bend digital coax all you want and it will work just fine(provided you don't break the conductor).

There is a minimum bend radius with coax as well. All cables have a minimum bend radius to keep their properties.

Every cable has a minimum bend radius. This can be due to the electrical characteristics or a simple requirement to guarantee it will not break. But to say "You can't bend it much either, much like an optical cable or it will go out of impedance. " is ridiculous.

Considering that digital coax works even if you use a 50ohm audio cable. I think variations in cable impedance really aren't that big of a deal. Maybe with measurement equipment...but not in practice.

Keep in mind that the rated impedance is Nominal. Even a cable which is not bent will vary in characteristic impedance throughout...especially at the connectors.

 

[spidey07]

Originally posted by: PurdueRy

Originally posted by: spidey07

Originally posted by: PurdueRy


And you can bend digital coax all you want and it will work just fine(provided you don't break the conductor).

There is a minimum bend radius with coax as well. All cables have a minimum bend radius to keep their properties.

Every cable has a minimum bend radius. But to say "You can't bend it much either, much like an optical cable or it will go out of impedance. " is ridiculous.

Considering that digital coax works even if you use a 50ohm audio cable. I think variations in cable impedance really aren't that big of a deal. Maybe with measurement equipment...but not in practice.

C'mon Purdue. You know what reflections are. The difference between 50 and 75 ohms is pretty dang big. I thought they still had good test gear at MSEE (if the building is still even there)

 

[PurdueRy]

Originally posted by: spidey07

Originally posted by: PurdueRy

Originally posted by: spidey07

Originally posted by: PurdueRy


And you can bend digital coax all you want and it will work just fine(provided you don't break the conductor).

There is a minimum bend radius with coax as well. All cables have a minimum bend radius to keep their properties.

Every cable has a minimum bend radius. But to say "You can't bend it much either, much like an optical cable or it will go out of impedance. " is ridiculous.

Considering that digital coax works even if you use a 50ohm audio cable. I think variations in cable impedance really aren't that big of a deal. Maybe with measurement equipment...but not in practice.

C'mon Purdue. You know what reflections are. The difference between 50 and 75 ohms is pretty dang big. I thought they still had good test gear at MSEE (if the building is still even there)

Yes, those reflections are fairly significant. However, quite a bit of the signal still reaches the destination. As long as this is enough to detect, it will work just fine.

I should also note that the reason that this doesn't matter so much for most HT applications is due to the relatively short length of wire often used in HT. The longer the wire...the more important this is.

And just to give a practical example. Lets assume that we have a 50 ohm cable with 75 ohm sources. The magnitude of reflection at each end is .2

by the time the wave gets to the load it is at .64 its magnitude. The reflection when it gets back to the load is .04 the original magnitude. That is a pretty steep difference. Provided that .64 of the magnitude is enough for the load to recognize as a "1" then it will still work.

Certainly this would be a worst case scenario. After all, my only point was that bending a coax cable will not cause enough reflections to cause improper operation.

 

[Auric]

Originally posted by: YOyoYOhowsDAjello

Originally posted by: PurdueRy

Originally posted by: nguyendot1
For all intensive purposes, and for the audience this thread is pointed at, optical and coaxial are the same.

pure....digital.....speakers.....

Does....not....compute

I stopped paying attention at "intensive purposes"

They must have meant tents & porpoises. Oh the huge manatee!

 

[migo]

How about coax cables acting as antennae when your cell phone starts seeking? Is there some design feature that makes this less of an issue than standard 3.5mm jack cables?

 

[alfa147x]

Its not that hard, The toslink has a red light so it got to better

 

[Auric]

Originally posted by: migo
How about coax cables acting as antennae when your cell phone starts seeking? Is there some design feature that makes this less of an issue than standard 3.5mm jack cables?

Que? What do you mean by "than"? 3.5mm jack in Toslink (optical fiber) or RCA (electrical coaxial)?

Fiber optic is obviously immune to interference and likewise electrically isolates each device. However, proper shielding and interconnects preclude the possibility of most interference with coaxial. There is even less chance if properly routed -i.e. not in parallel, especially with power cables, &c. A ground loop can still occur but that isn't caused by the cable, per se.

 

[migo]

than with...

I'm talking about the normal cables that you get with most speaker systems. Every time I place a call or get an incoming call I can hear it ahead of time on my speakers since the cable picks up the signal. That's mainly dependent on the length of the cable from what I understand. Are S/PDIF coax cables shielded in such a way that this doesn't occur?

 

[Auric]

S/PDIF is, as the name says, just an interface. The coaxial cables used are the same as for TV (RG-6 or RG-59). So yes, they are specifically shielded against interference. They could replace audio cables (or video) but not speaker wire in general useage due to the need for a larger conductor. Most speaker wire included with systems is very small though. If that is the case you could either try a larger gauge (lower number) or get more costly shielded wire -still, ideally the gauge should be matched for the length.

 

[PurdueRy]

Originally posted by: migo
than with...

I'm talking about the normal cables that you get with most speaker systems. Every time I place a call or get an incoming call I can hear it ahead of time on my speakers since the cable picks up the signal. That's mainly dependent on the length of the cable from what I understand. Are S/PDIF coax cables shielded in such a way that this doesn't occur?

not likely to happen. With analog cables any signal induced into the cable WILL be played out the speakers. With a digital connection you have to induce a 1 or a 0...which is fairly hard to do.

 

[migo]

Thanks. That makes perfect sense.

 

[PurdueRy]

Originally posted by: migo
Thanks. That makes perfect sense.

Another option is to buy shielded 3.5mm cables. I believe most 3.5mm cables that come with speakers sets aren't shielded...or at least not well. This makes them perfect antennas.

 

[migo]

Will shielded 3.5mm cables pretty much guarantee that they won't act as antennae or am I best off going digital as well?

 

[PurdueRy]

Originally posted by: migo
Will shielded 3.5mm cables pretty much guarantee that they won't act as antennae or am I best off going digital as well?

I would try some cheap shielded cables first.