Questions for the audiophiles

[Arkitech]

I just recently bought a new receiver (Onkyo TX-SR503) and I'm in the process of converting my rca cables to either spdif or optical. Does anyone know the technical difference between the 3 formats? Which is better, spdif or optical? Is the difference between rca and spdif or optical the same as compsoite and component or hdmi?


Finally one last question, I'm wiring up my first subwoofer (5.1) and it has the following inputs on the back:

Amplifier: left -/+ and right -/+
Speakers: left -/+ and right -/+

Which speakers should I connect to the subwoofer: rear, front or center channel?

 

[Muse]

Originally posted by: Arkitech
I just recently bought a new receiver (Onkyo TX-SR503) and I'm in the process of converting my rca cables to either spdif or optical. Does anyone know the technical difference between the 3 formats? Which is better, spdif or optical? Is the difference between rca and spdif or optical the same as compsoite and component or hdmi?


Finally one last question, I'm wiring up my first subwoofer (5.1) and it has the following inputs on the back:

Amplifier: left -/+ and right -/+
Speakers: left -/+ and right -/+

Which speakers should I connect to the subwoofer: rear, front or center channel?

RCA cables are already broken out into channels and the signal is analog and generally line level. At that level it just needs amplification in order to be ready for a speaker. That amplification is done by your receiver. You may or may not have a powered subwoofer. If powered, you feed it the line level subwoofer output from your receiver. If it's not powered, you have to use an amplified subwoofer output from your receiver. Or, judging from what you say about your subwoofer inputs it may support signal conversions. However, if your subwoofer is powered you definitely want to use the line level subwoofer output from your receiver. Read your manuals.

SPDIF can be either coaxial or optical. In my experience, optical is better, but you may not find that to be the case in your situation. It think it's because my receiver is sort of low end and has glitches with the coaxial SPDIF. SPDIF has all the channels still together and it's a digital signal. I has to be decoded (by your receiver) and converted to analog signals that are sent to the speakers after amplification. Coaxial SPDIF is transmitted to your receiver on a cable that looks like an RCA cable, however the signal is digital, as stated.

Usually (in my case) my receiver has a subwoofer output and you just wire that to the wubwoofer. Check your receiver's manual for instructions.

 

[Slick5150]

I think you're asking for the difference between Coaxial & Optical digital (SPDIF isn't a type of cable)

In reality, you won't notice a difference between the 2. Some will argue that Coax is technically superior (due to less chance for noise introduction I believe), but unless you have a bad optical cable I can't imagine you being able to notice a difference. So go with whatever is easier.

As for what speakers to hook up to the sub, you don't really have to hook any up. Some audio setups you can do it that way and let the subwoofer pull out the LFE, but if your receiver is decent it will do a good enough job of that, so hook all the speakers and the sub directly to the receiver and you should be fine.

 

[YOyoYOhowsDAjello]

Does your sub have an RCA input rather than speaker wire inputs, or does it not have its own amp?

RCA input is going to be analog so if your input device is going off of source material that's digital, the quality of the input device's DACs are going to be a factor. This isn't necessarily a bad thing though depending on your source.

If you send SPDIF, you are letting the receiver do the DAC conversion and decoding of DD/DTS streams etc.

So, RCA analog is very different in what happens with digital coaxial or digital optical. As for the two digital methods, they should produce the same results. I personally think optical is a nicer way to do it because you avoid the ground loop problem and you can't really get interference from other cables nearby. Digital Coaxial cables are easier to find for long runs though.

If you already have some yellow RCA cables that are 75ohm, you can use those for digital coaxial connections.

 

[Tiamat]

In addition to the above, if you have good DAC's and/or you cant tell the difference between "ok DAC's" and totally digital connectivity (to allow receivers DAC's to do the work) then the only difference is cable clutter. Obviously for 5.1 you need 5 RCA cables whereas a single digital cable carries all the signal.

 

[Gibson486]

For one, Spidf, which is coax or optical, is completely digital.

 

[Zugzwang152]

Originally posted by: YOyoYOhowsDAjello
Does your sub have an RCA input rather than speaker wire inputs, or does it not have its own amp?

RCA input is going to be analog so if your input device is going off of source material that's digital, the quality of the input device's DACs are going to be a factor. This isn't necessarily a bad thing though depending on your source.

If you send SPDIF, you are letting the receiver do the DAC conversion and decoding of DD/DTS streams etc.

So, RCA analog is very different in what happens with digital coaxial or digital optical. As for the two digital methods, they should produce the same results. I personally think optical is a nicer way to do it because you avoid the ground loop problem and you can't really get interference from other cables nearby. Digital Coaxial cables are easier to find for long runs though.

If you already have some yellow RCA cables that are 75ohm, you can use those for digital coaxial connections.

way to earn your custom title :thumbsup:

/me cracks the Night Crew whip.

 

[Rubycon]

Balanced i/o (XLR) for analog and AES/BU for digital stuff.

RCA and SPDIF is usually found on cheaper stuff.

 

[YOyoYOhowsDAjello]

Originally posted by: Zugzwang152

Originally posted by: YOyoYOhowsDAjello
Does your sub have an RCA input rather than speaker wire inputs, or does it not have its own amp?

RCA input is going to be analog so if your input device is going off of source material that's digital, the quality of the input device's DACs are going to be a factor. This isn't necessarily a bad thing though depending on your source.

If you send SPDIF, you are letting the receiver do the DAC conversion and decoding of DD/DTS streams etc.

So, RCA analog is very different in what happens with digital coaxial or digital optical. As for the two digital methods, they should produce the same results. I personally think optical is a nicer way to do it because you avoid the ground loop problem and you can't really get interference from other cables nearby. Digital Coaxial cables are easier to find for long runs though.

If you already have some yellow RCA cables that are 75ohm, you can use those for digital coaxial connections.

way to earn your custom title :thumbsup:

/me cracks the Night Crew whip.

:Q

 

[YOyoYOhowsDAjello]

http://forums.anandtech.com/messageview...atid=27&threadid=1697633&enterthread=y

You saw that I said this Chaintech is only going to do stereo for games, right?

 

[Arkitech]

Thanks for the info fellas, much appreciated.

Yoyo - Unfortunately my subwoofer does'nt have its own amp or rca jack, its going to be powered by the receiver. (in fact the speakers I'm using are really cheap ones, they're a set of KLH 9900's I inherited awhile back)

How do I know if my cables are 75ohm or not? I have a set of RCA cables (black and red) that are gold plated and a bit thicker than the average cable.


One other question I bought 2 spools of Philips 14 gauge speaker wire, will that be sufficient for my setup? I've heard the lower the gauge the better but I could'nt find anything lower than 14.

 

[Arkitech]

Originally posted by: YOyoYOhowsDAjello
http://forums.anandtech.com/messageview...atid=27&threadid=1697633&enterthread=y

You saw that I said this Chaintech is only going to do stereo for games, right?

This is kinda funny, I was poking around the PC parts and boxes in my basement this morning and I realized that about a year ago I had purchased 2 Creative Labs E-MU 0404 cards that I never used. I had intended to use the cards for a home studio but I never got around to finishing the project, so anyway to make a long story short after examing the cards I realized that they have both optical and spdif outs. They also support 24-bit/96khz, not that I really know what that means.

 

[Gibson486]

Originally posted by: Arkitech
Thanks for the info fellas, much appreciated.

Yoyo - Unfortunately my subwoofer does'nt have its own amp or rca jack, its going to be powered by the receiver. (in fact the speakers I'm using are really cheap ones, they're a set of KLH 9900's I inherited awhile back)

How do I know if my cables are 75ohm or not? I have a set of RCA cables (black and red) that are gold plated and a bit thicker than the average cable.


One other question I bought 2 spools of Philips 14 gauge speaker wire, will that be sufficient for my setup? I've heard the lower the gauge the better but I could'nt find anything lower than 14.

most cable have an impedance of 75 to 80 ohms. Some weird ones have an impedance of 90 ohms, but those are not sold in places like best buy. the lower the gauge the better? No, in reality, it wont really matter what gauage wire you use as long as the wire is not to small, but the bigger cable usually means that is it sheiled better (less inductance and cross talk, but this all theroy and theory has a way of making better marketing).

 

[Arkitech]

Yet another question

Any idea of what spdif and optical cables should cost? I'm going out to make a cable run and don't want to overspend. I also need to pick up a few mini pins to connect my speakers.

 

[YOyoYOhowsDAjello]

Originally posted by: Arkitech
Thanks for the info fellas, much appreciated.

Yoyo - Unfortunately my subwoofer does'nt have its own amp or rca jack, its going to be powered by the receiver. (in fact the speakers I'm using are really cheap ones, they're a set of KLH 9900's I inherited awhile back)

How do I know if my cables are 75ohm or not? I have a set of RCA cables (black and red) that are gold plated and a bit thicker than the average cable.


One other question I bought 2 spools of Philips 14 gauge speaker wire, will that be sufficient for my setup? I've heard the lower the gauge the better but I could'nt find anything lower than 14.

The red and white ones should acutally work, but if you have ones that are yellow video ones, those are the technically correct ones to use (75ohm vs ??ohm).

14 gauge is good. You should be just fine with that for normal distances.
Speaker wire info

 

[YOyoYOhowsDAjello]

Originally posted by: Arkitech

Originally posted by: YOyoYOhowsDAjello
http://forums.anandtech.com/messageview...atid=27&threadid=1697633&enterthread=y

You saw that I said this Chaintech is only going to do stereo for games, right?

This is kinda funny, I was poking around the PC parts and boxes in my basement this morning and I realized that about a year ago I had purchased 2 Creative Labs E-MU 0404 cards that I never used. I had intended to use the cards for a home studio but I never got around to finishing the project, so anyway to make a long story short after examing the cards I realized that they have both optical and spdif outs. They also support 24-bit/96khz, not that I really know what that means.

The analog out from those might be your best option if you have a rather cheap receiver.

 

[YOyoYOhowsDAjello]

Originally posted by: Arkitech
Yet another question

Any idea of what spdif and optical cables should cost? I'm going out to make a cable run and don't want to overspend. I also need to pick up a few mini pins to connect my speakers.

Cheap optical cables
Cheap digital coax cables (If you don't just want to use some RCA cables)
The Chaintech came with an optical cable, didn't it? (I don't know if you're keeping that one)

Partsexpress should have reasonably priced connectors for your speakers if you don't want to use bare wire.
EDIT: I looked through partsexpress but only found banana plugs and not any pins.... they might have some but I didn't see any.

 

[Inspector Jihad]

resurecting this thread for my question: I'm a noob so I was wondering how much differece there is in going from analog RCA to optical? My reciever I got with the Onkyo HT-S780 does have optical and i was wondering if i should go out and get a bunch of optical cables? Also, does it make a difference in video to go from analog RCA to component...i mean it would definetly make a difference, but how obvious is it? Thanks guys

 

[Howard]

RCA is a type of connector used with 75O-impedance coaxial cables (like the cable you used to screw into the back of your TV, although that's a different connector).

S/P-DIF (Sony/Philips Digital Interface Format) is a digital interface that runs over 75O coax. Optical is typically TOSLink, a plastic fiber optic cable. You will not hear a difference between high-quality (not necessarily high-priced) RCA interconnects and TOSLink interconnects.

 

[Howard]

Originally posted by: Inspector Jihad
resurecting this thread for my question: I'm a noob so I was wondering how much differece there is in going from analog RCA to optical? My reciever I got with the Onkyo HT-S780 does have optical and i was wondering if i should go out and get a bunch of optical cables? Also, does it make a difference in video to go from analog RCA to component...i mean it would definetly make a difference, but how obvious is it? Thanks guys

Not much.

 

[Inspector Jihad]

ok, so is it worth to switch everything to component and optical?

 

[spidey07]

Originally posted by: Inspector Jihad
ok, so is it worth to switch everything to component and optical?

yes.

Just don't make the mistake most do and use non-component cables on component connections (ie, using the red/white/yellow 3way cables for a component video connection - bad mojo.)

 

[Inspector Jihad]

Originally posted by: spidey07

Originally posted by: Inspector Jihad
ok, so is it worth to switch everything to component and optical?

yes.

Just don't make the mistake most do and use non-component cables on component connections (ie, using the red/white/yellow 3way cables for a component video connection - bad mojo.)

no i bought the component cables...but as a question, why would that be bad?

 

[YOyoYOhowsDAjello]

Originally posted by: Inspector Jihad
resurecting this thread for my question: I'm a noob so I was wondering how much differece there is in going from analog RCA to optical? My reciever I got with the Onkyo HT-S780 does have optical and i was wondering if i should go out and get a bunch of optical cables? Also, does it make a difference in video to go from analog RCA to component...i mean it would definetly make a difference, but how obvious is it? Thanks guys

What are you connecting?

If you're connecting a DVD player or something, a digital connection is going to be the way to go as you'll be able to get surround sound vs stereo analog most DVD players offer.

As for the video, composite vs component difference is going to depend on the source material and the kind of tv you have, but definately go for component vs composite if you have the cables already.

 

[YOyoYOhowsDAjello]

Originally posted by: Inspector Jihad

Originally posted by: spidey07

Originally posted by: Inspector Jihad
ok, so is it worth to switch everything to component and optical?

yes.

Just don't make the mistake most do and use non-component cables on component connections (ie, using the red/white/yellow 3way cables for a component video connection - bad mojo.)

no i bought the component cables...but as a question, why would that be bad?

It would probably still work just fine, but you want to use 75-ohm RCA for the component connections. The yellow video cables should be 75-ohm, so if you got them plugged into the correct connections, three video RCA cables should work well too.

EDIT: heh, I already said all this in the thread in september