jasonbird

I guess I have a couple of questions about this kind of connection.
Is this connection better than using the Digital Audio? My under-
standing is that if you have a reciever with a decoder you use the
digital connections and if you don't, you can use the decoder in
the dvd player with the 5.1 outs. Am I correct?

I'm getting the Toshiba SD-4900 for Christmas and it has both
types of digital outs (optical and coaxial) and it has a place for
each individual 5.1 inputs. Which is the best way to connect this
to my receiver? My receiver has both DD and DTS decoders.

Thanks for everyones help, and Merry Christmas!

Jason

Illinois Enema Bandit

If your receiver has DD/DTS (most do nowadays), just use the coax or optical connection for your DVD player.

The 5.1 outputs on the DVD player are for connecting to "digital ready" receivers i.e. those which don't have onboard DD/DTS decoding

As to whether you should use coax or optical: I'm of the view that it's 6 of one/half-dozen of the other. Receivers tend to have more optical inputs than coax inputs, and you may also want to consider other digital devices that need connecting to your receiver (either now or in the future), such as cable boxes or satellite boxes

hoyalawya

Theoretically, both coaxial and optical connection should sound the same since they are both digital. However, that is not always true. Some DVD players handle coaxial better while some handle optical better. For me, I prefer coaxial over optical. It seems that the optical converter in my DVD player is not as efficient (in converting 1 and 0 into light) as coaxial. You should try both and see which one you prefer.

Michael Corvin

I was under the assumption that 99% of dvd players nowadays don't come with the a decoder, since 99% of all receivers now have it built in. That was the reason for some of the higher prices on the first & second generation players.

But hey I could be wrong.

I use optical.

Mr. Salty

There are a fair number of players with built-in Dolby Digital decoders, but built-in DTS decoders are considerably more rare. Most DVD players simply pass the DTS bitstream (the player will be marked DTS Digital Out).

chipmac

Just want to add that if your DVD player also handles DVD-A or SACD then you'll need to hook up the 5.1 analog to hear those formats along with the coax or optical for DD and DTS.

chowchris13

I work in a high-end audio store and generally we recommend using a coaxial cable over an optical....coax is a straight digital transfer while with the optical it has to transfer from digital to light back to digital so its loses some signal during the transfer...but you have to compare apples to apples....$100 optical cable will be better then a $50 coaxial

Frank S

This is NOT true! If you were losing bits along the line you would be getting dropouts in your audio. You need to stop think Analog when dealing with Digital because they are hugely different in their capabilities and requirements. If you do NOT get dropouts in your audio via Optical or Coxial digital cables you are getting all the bits that are coming from the DVD/CD. And using a Coaxial cable has the same amount of conversion being done (one) as does a Optical cable does since the DVD player must convert the digital bits from the laser pickup (optical) to analog (coaxial) as opposed to using a Optical cable where the DVD player passes the digital optical bits straight from the laser pickup to the Optical cable and then the conversion is done in the receiver.

Contrary to what some will have you believe, working with bits is a very easy thing to do and the conversion from optical to the final bits used by a receiver is a very easy and uneventful transition that very rarely causes any problems. The only difference between Coaxial and Optical that needs to be considered is that Coaxial is cheaper (since it is merely a good quality 75 ohm video cable) yet it does not allow as long a run as Optical. Optical on the other hand is more expensive (not a whole lot) then Coaxial but it can be run with longer lengths then Coaxial can. The other drawback to Optical cable can not be crimped at all (or extremely bent) or it will snap inside.

cowanrg

i agree with chowchris.

being another person that works in the industry...

its not all 1's and 0's like people think. its not all or nothing. lets do some math!

for a standard cd (a much MUCH smaller bitrate than a dvd), we have 16 bits of information being sampled at 44Khz. this means that its being sampled 44,000 times in one second. we then have 704,000 bits of information each second. these are transmitted. lets say 1% gets lost. you will still hear the sound, and it will be nearly identical, because 99% of it got there ok. but that 1% is still 70,000+ bits of information.

with computers or most things, this wouldnt be an issue, the equipment would still work just fine. but with audio, you can hear a slight lack of dynamics and clarity.

dvd's have a bitrate at around 96khz at 24 bits. this is 2,304,000 bits each second! think if just a mere 1% were lost there!

the idea is to get it ALL there, not just enough to stop an audio dropout from happeneing...

and frank, ive read your post, and i almost cracked up

just because the information starts as optical doesnt mean it just passes straight through to the optical out. its not like pipes... it still goes through the transport section where it is a AC signal. then its converted into optical signals, then at the other end back to AC voltage signal.

a digital coax just skips the whole conversion to optical, thats all. it is a shorter signal path, a superior connector, etc. the only reason why the optical has stuck around is because sony and phillips (s/pdif = sony/philips digital interface), dropped tons of money into it and basically made is much cheaper to use for a lot of companies making dvd/cd players.

in ANY event, get two cables, test it out. if you cant hear a difference, keep the cheaper cable, or the one that is more flexible with inputs for your receiver.

X

This is not correct for DD and DTS. Those two are encoded and compressed signals that either get to the receiver correctly to be decoded or they don't. You won't get a difference in dynamics and clarity, you'll get a very noticeable dropout if the signal gets to the receiver in bad enough shape that even the error-correction circuitry in the decoders can't repair it to be 100% exactly the same as the signal that was sent. Much as a damaged zip file won't unzip if a bit is wrong. There will be a noticeable dropout of audio if bits don't get passed correctly, not a slight nuance difference in the sound.

This is why you can use the lowest-end digital-out card in a home theater computer if you are only passing DD/DTS. If you are passing PCM such as CD audio out, the quality of the components matters much more as the bits are not compressed and encoded.

Oh, and if you lost 1% of the bits in a computer you would have serious problems on your hands. Like it not working at all. I'd call that an issue.

Frank S

Talk about laughable! I'm sorry to burst your bubble but it IS all 1's and 0's plain and simple. Unless you have some type of revelation that DVD's now secretly have analog NOT digital (which means 1's and 0''s ONLY i.e. bits) then you have no leg to stand on!

You can talk all you want about changing sound quality but this is NOT the case in the Digital realm as it was in the Analog realm! There is NO WAY for the sound to be altered by simple lose of bits but will only surface as dropouts in the audio or pixilazation in the video.

Mr. Salty

I hope you're kidding about this part. Please tell me you're kidding. You're kidding, right?

PJAceto

For an electronic engineer's take on this issue, check out the white paper at:

http://members.cox.net/pjaceto/

X

Thanks!

That was a very good explanation of what happens (and doesn't happen) with DD encoded signals.

The author, whoever he is , appears to know what he's talking about.

Mr. Salty

But X, this is one of those debates where people will never let facts get in their way!

PJAceto

Thanks for the compliment.

Ergyu

Yes indeed that was an excellent read. I was always told that there was no difference, and have always stuck to Coax simply because it was less expensive. Optical does have a "cool" factor though, I will admit that.