What the heck is "digital audio out" on TV?

[nat whilk II]

So we're looking at a Costco deal for a big LCD HDTV. It comes with speakers, which I'm sure are atrocious.

 

We've got a decent amp that we use for TV sound. The specs on this Costco LCDTV show a "digital audio out".

 

What in the world could that be?????

 

What would you plug the other end of this digital out INTO?

 

With all this hi tech music stuff I do, I must be falling behind what in what the consumers are consuming...

 

nat whilk ii

[spokenward]

The ATSC standard supports connection to a multi-channel audio system. It presents using the same digital connections (S/PDIF coax or TOSLINK) that we use for audio production, but the format is packed differently. There are a few different flavors - they use a lossy compression scheme:

 

http://en.wikipedia.org/wiki/ATSC_%28standards%29

http://www.digitalpreservation.gov/formats/fdd/fdd000209.shtml

 

The wiki page footnotes link to the Dolby docs.

http://en.wikipedia.org/wiki/Dolby_Digital#Applications_of_Dolby_Digital

 

A multi-channel audio system (these days) means a 5.1 (or better) Home Theater receiver. Starting with DVDs we have had a format for multi-channel audio in the home. Content is encoded for 5 directional placements and a sub. Dolby pdf overview

[Cry Logic]

 

"....The specs on this Costco LCDTV show a "digital audio out". What in the world could that be????? What would you plug the other end of this digital out INTO?...."

 

 

The answer is obvious Nat.

You plug it into any device that has a compatible digital audio in.

Like my Altec Lansing ADA 880 speaker set.

I can go straight from the digital out on my PC's motherboard

to the digital in on the ADA 880's sub woofer (which also houses

the amplifiers for the speakers).

The ADA 880s have a DAC which does the conversion.

[nat whilk II]

Yeah, you're right in that it is obvious that something that receives digital would be at the other end of the digital out, but what that something is for a TV was the jist of my question. Bear in mind I buy a new TV every, oh, 15 years or so at the most. Just not into that.

 

See all I want is good old analog stereo out from the LCDHDTV. Don't care about 5.1 and all that. Am I the only person somewhat surprised there are no analog stereo L/R audio outs (except for the "earphones" out) on any particular unit?

 

So is it the case that all the 5.1 speaker sets use digital-only connectors? And that analog stereo audio outs on TVs are going away, if not already gone?

 

I don't want to have to buy yet another gizmo just to route the audio to my old stereo tuner/amp which, of course being old, has no digital input.

 

Also - I'm not sure I can intuit the benefit of having DACs built into speakers. What's the advantage? Willing to learn....

 

nat whilk ii

[doug osborne]

(as fretwiz said) ATSC TV uses Dolby Digital to carry audio.

 

This can be anywhere from one channel to six. If you have a digital device at the other end that can decode DD, it will downmix to two channels, no problem.

 

I'm lucky enough to have just gotten a nice digital TV (Samsung 46" LCD/LED 1080p 240 Hz etc., my first new TV in over a decade. wow, what a picture). It does have one stereo analog audio output - audio is received digitally, but gets decoded in the set and sent out these RCA jacks (digital inputs, via HDMI, get sent out digitally, but only as two-channel, bummer). So, I don't know that analog outputs are gone.

 

Why not use the headphone output?

 

Any system that transmits sound digitally and decodes to analog at the last possible point has the potential to have less loss than a system that converts digital to analog early and transmits it over analog circuitry and cables (not a digital v. analog debate...this system has a D/A converter somewhere in its path , and it should be at the end). Of course if the source has a great D/A and the speakers/receiver/processor has a crappy D/A, you might have different outcomes (as with all systems).

[nat whilk II]

 

(as fretwiz said) ATSC TV uses Dolby Digital to carry audio. This can be anywhere from one channel to six. If you have a digital device at the other end that can decode DD, it will downmix to two channels, no problem. I'm lucky enough to have just gotten a nice digital TV (Samsung 46" LCD/LED 1080p 240 Hz etc., my first new TV in over a decade. wow, what a picture). It does have one stereo analog audio output - audio is received digitally, but gets decoded in the set and sent out these RCA jacks (digital inputs, via HDMI, get sent out digitally, but only as two-channel, bummer). So, I don't know that analog outputs are gone. Why not use the headphone output? Any system that transmits sound digitally and decodes to analog at the last possible point has the potential to have less loss than a system that converts digital to analog early and transmits it over analog circuitry and cables (not a digital v. analog debate...this system has a D/A converter somewhere in its path , and it should be at the end). Of course if the source has a great D/A and the speakers/receiver/processor has a crappy D/A, you might have different outcomes (as with all systems).

 

 

 

Headphone outputs - for us, the main reason not to use is that we're picky about appearance as this tv will be in the main living room-don't want a permanent line hanging off the front of the tv routed to the back.

 

Also, the more frequent the use of a dinky, consumer-level headphone input means the thing will probably fail/start cutting in and out before too long. Who hasn't experienced that with headphone jacks?

 

Just want nice, solid RCA jacks hidden in the back, like God intended.

 

I find your comment about "loss" occurring over an analog wire interesting. What kind of loss happens? I can see RF interference as an issue maybe, but "loss" I don't know what's referred to in this context.

 

Now I'm guessing that maybe cabling expense is a point in all this - if you have a 7.1 system strung out over a large room, I would think optical cable to each speaker would be a lot cheaper than quality analog speaker cable. So that would be a reason to go digital to each speaker that makes sense to me.

 

Thanks for all the info.....gotta be an eddicated consumer or what will the neighbors think:eek:

 

nat whilk ii

[Jeff Leites]

FYI, the digital audio output on the TV can be optical or coax, and the digital audio input on a surround sound receiver can also be optical or coax (sometimes both, but maybe not enough inputs of the type you need). The solution for a mismatch is a S/PDIF Coaxial to Toslink Optical Digital Audio Converter or an Optical to Coaxial digital Audio Converter. They are only about $16 dollars. When I needed one, I couldn't find one in the stores, but they are easy to find on-line.

[Mr. Botch]

Nat, I'm surprised the TV you're looking at has digital out but not component (analog) out. What make is it?

I just had a home theater installed the last couple weeks, and my LG had both. The digital out was optical, and the installers used an optical-to-coax converter like Jeff described to send a coax to my receiver.

So, I could hear Oprah's audience applauding all around me, o joy! (wish the installers could've picked a different channel to test things... ).

Does your present amp convert 5.1 to stereo?

[MikeRivers]

 

Bear in mind I buy a new TV every, oh, 15 years or so at the most. Just not into that. See all I want is good old analog stereo out from the LCDHDTV. Don't care about 5.1 and all that. Am I the only person somewhat surprised there are no analog stereo L/R audio outs (except for the "earphones" out) on any particular unit?

 

Yeah, I feel your pain. I've had the same TV set for about 25 years (and still do) and just got one of those newfangled LCD TVs to replace the little one in my bedroom that died. It was a cheap one but like yours, its only analog output (other than the built-in speakers) is a headphone jack. It also has a digital audio output but I've never tried connecting it to anything to see what comes out. The nearest digital input is half a house away.

 

Just go ahead and use the headphone jack. It's as good as you're going to get out of a TV set. For my purposes (falling asleep to the 11 o'clock news), the built-in speakers are just fine.

[nat whilk II]

Nat, I'm surprised the TV you're looking at has digital out but not component (analog) out. What make is it? I just had a home theater installed the last couple weeks, and my LG had both. The digital out was optical, and the installers used an optical-to-coax converter like Jeff described to send a coax to my receiver. So, I could hear Oprah's audience applauding all around me, o joy! (wish the installers could've picked a different channel to test things... ). Does your present amp convert 5.1 to stereo?

 

 

Oy you must understand how totally 70s my understanding of tv is...my "present amp" is my old NAD stereo amp I used for playing vinyl in another world and time. Present tv is a quite old and outdated Sony 27" we bought used from some grad students moving out of the country that has nice olfashion' analog audio L/R outs. I just rigged up the old stereo amp to get better sound and route the audio to my ancient Phase Linear stereo speakers also from the Vinyl Age.

 

I got nothing to plug a digital out from a tv into unless I run it into my studio PC, but this tv ain't gonna be in the studio.

 

But HEY - you used the term "component" out. Not a term I'm familiar with. Does that refer to an audio out??? Or does it mean analog video out??

 

here's the model and specs from Costco's recent on sale stuff from their website:

 

 

Proscan 40" 1080p

 

the specs from Costco's ad:

 

Inputs/ Outputs:

 

HDMI x 3

Component x 2

S-Video Input x1

AV Input x 1

Antenna Input x1

VGA input x1

Audio Input (PC Stereo) x1

Audio Output (Earphone) x1

Digital audio out x1

 

If "componet x 2" means it's got analog audio outs, then I'm home free....

 

and $499 sounds like a decent price to me, but being a LCDHDTV nOOb among nOObs, what do I know?

 

thx for all the help...

 

nat whilk ii

[Jeff Leites]

I think those 2 sets of component jacks are video inputs (colored Red Blue and Green) for connecting the component video output of two other devices to you TV. I'd think that there would be an audio input associated with each one. These days, more external devices are equipped with HDMI outputs, and you have 3 HDMI inputs on your TV. I think on most but not all devices, the HDMI carries the audio as well as the video.

 

[YOUTUBE][/YOUTUBE]

[MikeRivers]

 

Present tv is a quite old and outdated Sony 27" we bought used from some grad students moving out of the country that has nice olfashion' analog audio L/R outs. I just rigged up the old stereo amp to get better sound

 

My TV living room set is older and smaller than yours, and it's from the days before there was stereo TV broadcast. Even if it did have an analog output (and it doesn't - but it has a built-in speakerphone!) it would be mono. When I got a VCR (which had a stereo analog audio output) I hooked that up to the living room stereo system, and if I wanted to listen to a broadcast TV show in "better" quality, I muted the TV audio and listened to the audio that came from the VCR. But it was rarely worth the inconvenience of not having the Mute button on the remote for the VCR audio when commercials came on. Also, while it was in stereo, the audio quality was almost always pretty poor, the mix wasn't very good, and I heard all the imperfections. While I can't say that the sound was "better" out of the TV speakers, it was less annoying. About the only time I ever listen to audio for video through the stereo system now is if I'm watching as program on DVD, where they usually care about decent audio.

 

you used the term "component" out. Not a term I'm familiar with. Does that refer to an audio out??? Or does it mean analog video out??

 

Those connectors are for getting audio and video into the TV set from a VCR, DVD player, or digital TV converter, rather than for getting audio out. My new TV has several options pretty much like yours including composite video (video and audio through a single RCA jack or S-Video and two RCA jacks), "component" video and audio on three RCA jacks for the video and two RCA jacks for stereo audio) and HDMI, a new high resolution format that uses an expensive cable to carry video and audio into the TV and for which I have no outputs so I don't have to buy the cable. It also has a VGA connector so it can be used as a computer monitor, and since most computers have a mini jack for audio out, it has a corresponding jack for audio in from the computer.

 

But like yours, the only audio out of it is S/PDIF digital on an RCA jack, a headphone jack, and the audio that comes through the HDMI connector.

 

Like I said, if you insist, use the headphone jack to get audio out of the TV and into your stereo system. Or just listen on the TV speakers. You probalby won't enjoy it any less. TV audio isn't getting any better.

[scud133]

I don't think there is any reason to have a "Digital Audio Out" on the tv.

 

What you should do is run signal from your source (cable box, dvd player, etc) into your A/V receiver. It should never go direct to the TV at all.

 

The receiver should have the task of collecting and distributing all the different input sources, not the tv. The D/A converters in your tv are going to be crap by comparison, also.

[scud133]

ok Nat sounds like you don't have a 'receiver' per se, just an amp for your stereo system.

 

so here's what you do. you have two separate signal paths, one for video, and one for audio. all the video-only signals go from the source (cable, dvd, etc) into the tv. and all the audio-only signals go form the source to your amp.

 

that way your TV does what it does best (video) and your stereo system does what it does best (audio)

[doug osborne]

The TV has its own digital tuner, and needs its own digital out to go to receiver/processor/speakers/whatever.

[MikeRivers]

 

I don't think there is any reason to have a "Digital Audio Out" on the tv. The receiver should have the task of collecting and distributing all the different input sources, not the tv. The D/A converters in your tv are going to be crap by comparison, also.

 

That may be true in an A/V system but my TV sets get their signal off the air. No cable box, no satellites, and no "receiver."

 

In my case, if I had a receiver (one without a TV tuner) with a digital input (and many have them nowadays) I could use the digital audio output of the TV set to get the off-the-air audio to my living room speakers for (questionably) better audio.

[Jeff Leites]

 

That may be true in an A/V system but my TV sets get their signal off the air. No cable box, no satellites, and no "receiver." In my case, if I had a receiver (one without a TV tuner) with a digital input (and many have them nowadays) I could use the digital audio output of the TV set to get the off-the-air audio to my living room speakers for (questionably) better audio.

 

 

That's right, I'm an over the air user too. Antenna to TV, digital audio out to the surround sound receiver. The audio from the DVD player goes right into a digital input on the surround sound receiver too. The video from the DVD is component video to the TV, I might also have the analogue audio from the DVD player go to the analogue input on the TV (which would allow the DVD sound to come through the TV), but I never use it that way, I just used the DVDs digital output. My TV also has RCA analogue stereo outputs. I have them go to a another small bookshelf stereo receiver that I use when I don't need the big surround sound. The only reason I do that is because the TV has unusually crappy speakers build in that sound like a speaker phone, no exaggeration.

[Hard Truth]

I have a DVD player and a HD recorder and they both have digital out whch is just plain old SPDIF. Most newer receivers have SPDIF in. The signal can be encoded for Dolby surround but it is fully compatible with plain old stereo.

[Hard Truth]

"See all I want is good old analog stereo out from the LCDHDTV. Don't care about 5.1 and all that. Am I the only person somewhat surprised there are no analog stereo L/R audio outs (except for the "earphones" out) on any particular unit?"

 

I am surprised. In the worst case scenario you can use an adaptor cable to get your analog signal from the headphone out.

 

"So is it the case that all the 5.1 speaker sets use digital-only connectors? And that analog stereo audio outs on TVs are going away, if not already gone?"

 

Most speaker sets are not active, but apparently you are expected to have a receiver made in the last ten years, which would probably have digital inputs.

 

"I don't want to have to buy yet another gizmo just to route the audio to my old stereo tuner/amp which, of course being old, has no digital input."

 

Use the headphone out if you can't buy a new receiver.

 

 

"Also - I'm not sure I can intuit the benefit of having DACs built into speakers. What's the advantage? Willing to learn...."

 

I think that is rare, except for some products designed for use with a computer, which are designed to eliminate the need for several cables.

 

I don't know why people involved with audio aren't more interested in surround. I find it adds a lot to the viewing experience, more than a big new TV does.

 

I should also mention that many people don't use the tuner in the TV set, they use the tuner in their video recorder, which will most likely have analog outputs.

[Hard Truth]

By the way the TV might have analog audio outs and they just didn't bother mentioning them in the specs. If you don't want to get a new receiver maybe you should just choose another TV.