Optical Out vs Analog

[<><]

Hi, i've just ordered parts for a new build and ordered the bluegears b-Enspirer sound card (has DD/DTS encoding). The sound card will be connected to the logitech z-5500 speakers.
My question is, which would be better, using the Optical Out to connect to the speakers (everything will be encoded with the sound card) or just use the analog out? Any advantages or disadvantages?
And how would it work, if i use the optical out, for DVD movies that are already DD encoded? Would it just pass it thru or would it try to encode it again?

Thanks

[lowfat]

The only real disadvantage to using digital is CPU usage. Encoding to DD/DTS does take quite a bit of CPU power. For movies, etc. just turn off DTS/DD encoding and use a program that allows passthrough to SPDIF (i.e. PowerDVD)

[hifiking]

Decoding?

[lowfat]

Decoding?
:confused: what are you referring to?

[SexyMF]

DD/DTS encoding is done in hardware. The overhead for the CPU is insignificant.

Analog outputs are crap because:
- You need multiple leads for 5.1/7.1
- They cause electrical ground loops
- The cabling conducts noise
- Poor cables cause signal attenutation loose

Analog outputs are just old. Optical is the best.

[Helmore]

And what if the analog output of your soundcard is better then what optical can provide, in terms of bitrate and such? What is the best thing to do then?

[hifiking]

Are you guys decoding, bypassing or encoding a signal?

Bypass, less work for CPU, spdif out to amp.

Encoding, a nightmare for CPU, but only studios do this, and DD Live.

Decoding, from a DVD to analog signal, if you got good analog cables this might give the best performance.

Optical, less signal noise, and if you have a good decoder in your amp it might be good enough.

Coax, my prefered way, shielded from noise, one cable, good sound.

[003]

Depending on your equipment, SPDIF does NOT have to be better than analog out. With analog output your sound card converts the digital signal to analog so it is outputting an analog signal which can be readily used by your speakers. With SPDIF (digital; optical or coaxial) output, the sound card sends the untouched (only if using bitperfect, it can still be modified if you have certain dsp settings enabled) digital signal to an external device (certain speakers, cd and dvd players, dac, etc...) to be converted to analog. Digital can not be perfectly converted to analog and digital to analog converters (usually abbreviated as DAC) vary in quality. If you are using SPDIF output and the DAC in the device receiving the digital signal is not as good as the DAC in the sound card, then analog output would sound better.

A good example of this would be the Z-5500 speakers. When using digital output with them, the DAC that is in the Z-5500s will convert the signal to analog, but it's DAC is much lower quality than 90% of all decent sound cards, and the other 10% of sound cards would be so cheap that they don't even have a digital output.

FYI,
SexyMF, all those problems you pointed out with analog can still easily exist with the device you are using to receive the digital signal. Also, another digital-introduced anomaly is jitter, and I can guarantee you every pc sound card digital out will suffer from it.

[SexyMF]

Why are people still mentioning about CPU overhead for encoding. There is not any overhead. The encoding is done in the soundcard hardware. That is what you pay for.

You make good points about the quality of DACs. I was biased in that I have a Denon receiver so quality is good.

I just can't stand using so many cables for analog. Also, most cables sold are of terrible quality. They are far to thin. Same goes for the Composite video/S-video cables.

[Lestat]

Why are people still mentioning about CPU overhead for encoding. There is not any overhead. The encoding is done in the soundcard hardware. That is what you pay for.

You make good points about the quality of DACs. I was biased in that I have a Denon receiver so quality is good.

I just can't stand using so many cables for analog. Also, most cables sold are of terrible quality. They are far to thin. Same goes for the Composite video/S-video cables.


thats only partially true.
the encoding and decoding IS done by the sound card but they are cpu bound.
the cpu still handles the brunt of the work.

and Digital ie; Digital coax, Toslink, or Pin plug is still the best way to go.
one thing you have to realize with analog.
It always starts as digital, then is converted to analog, then when it hits the device its converted back into a digital signal. so ther ewill always be a quality loss in analog. unless its a 100% analog source and output device.

digital is less intensive as, yup you guessed it, no conversion of digital to analog and back again as its all digital.

dont question it just use the digital out.

[SexyMF]

thats only partially true.
the encoding and decoding IS done by the sound card but they are cpu bound.
the cpu still handles the brunt of the work.

What work exactly?

[003]

AFAIK the DSP and the DAC on the sound card do all the work unless you have a really cheap one that does everything in software.

[technodanvan]

dont question it just use the digital out.

Agreed.

Besides, I've been using the Auzentech XPlosion optical out using DTS Connect/DDL since it was available, on systems ranging from a 3200+ Sempron to a 3.7GHz Conroe...if there was any cpu overhead it was minimal on all systems, certainly never bogged any of them down to the point I couldn't play a game effectively or anything.

Add that to the reduced number of wires, its so much simpler. To be fair, there's no way you'd ever notice the difference between optical and analog connections on the Logitechs, but why be complicated when you can be simple? (in this case)