TV audio formats

[radioflier]

I noticed at the beginning of 'COLD CASE' last night a message saying "Available in HD 5.1 Suround". I know I have to purchase premium HDTV service from my cable company to get the HD video signal, but what about the audio? We currently do not have HDTV and will remain so for the forseeble future, and I have no plans to purchase HD service from the cable company. If I feed he audio signal from the TV into the 6.1 audio system I plan to buy, will I have the 5.1 audio I want?

[Sir Terrence the Terrible]

I noticed at the beginning of 'COLD CASE' last night a message saying "Available in HD 5.1 Suround". I know I have to purchase premium HDTV service from my cable company to get the HD video signal, but what about the audio? We currently do not have HDTV and will remain so for the forseeble future, and I have no plans to purchase HD service from the cable company. If I feed he audio signal from the TV into the 6.1 audio system I plan to buy, will I have the 5.1 audio I want?

Nope. NTSC specification only have enough bandwidth to cover a MTS stereo signal. So the best you can expect is a 2 channel stereo signal.

[radioflier]

Well, that sux!!! We're already feeding the TV audio signal in a 2-channel stereo and we're not happy with the results, particularly the difficulty in hearing/understanding the dialog. Most of it seems to be burried in with the music and background sounds of the soundtrack. We're at the point where we have to record everything we want to watch so we can chase-play it and go back and repeat segments where we can't understand what they're saying. Sometimes we have to revert to Closed Captioning! Much of the dialog is recorded low (compared to the music in the show - 'Las Vegas' is one of the worst offenders), and many actors have poor diction and fast-mumble their way thru the show - I was hoping a center channel would alleviate this.

I smell a conspiracy here - the producers make shows with bad soundtracks so you have to go out and buy new equipment. Then the cable people want their piece too and charge you extra to take advantage of the advances in technology.

[bobsticks]

Hi radioflier,

Perhaps you can improve your sound enough to avoid the whole chase-n-play fiasco.

If you were to run the stereo signal into a receiver with "Neo:6" or "All-Channel Stereo"
dsps, perhaps you could manipulate the sound more to your liking. It is my understanding that "ACS" modes have an artificial mono-mix of R&L being fed to the center channel. It is possible that you could utilize this scenario to raise the center channel volume and bring out the dialogue tracks...

...Caveat Emptor--I have never tried this, but it seems plausible theoretically. This will NOT give you true surround sound, but it might alleviate the need for constant playback or springing for monthly HD fees...

Anyone with any experience in this care to chip in?

Cheers and good luck

[JoeE SP9]

If you have a receiver that decodes Dolby Pro-Logic use that mode when watching conventional analog television. If the broadcaster says the transmission is HD 5.1 the corresponding analog signal will decode into a Dolby Pro-Logic signal. If your receiver will give the LFE output on 2 channel stereo it will also give an output from analog TV audio. If you or anyone else uses surround on FM be advised that analog TV audio is no different. FM is FM.:cool:

[s dog]

I use 7 channel stereo, That seem to sound the best to me.

[radioflier]

OK, there's apparently some confusion on my part here! I was thinking that I had to use the HD5.1 (digital) audio signal to get center channel dialog, but I forgot that same info can be obtained thru the analog side using the 2-channel signal and Dolby Pro Logic. Am I correct in that assumption?

[GMichael]

I like the Neo:6 for most TV shows.

[Sir Terrence the Terrible]

OK, there's apparently some confusion on my part here! I was thinking that I had to use the HD5.1 (digital) audio signal to get center channel dialog, but I forgot that same info can be obtained thru the analog side using the 2-channel signal and Dolby Pro Logic. Am I correct in that assumption?

Bingo!

[radioflier]

Bingo (as in there's some confusion on my part), or Bingo (yes, there is more than one way to getting what you set out to do)?

[Woochifer]

Your options for 5.1 audio are to either go HD, go with digital cable and a Dolby Digital-enabled set top box (need to check with your cable provider to see if they offer it), or go with a satellite service that allows for Dolby Digital simulcasts. I know that with Directv, you need a DD-enabled satellite receiver plus a parabolic dish to get 5.1 DD on the pay-per-view movies and HBO.

The difficulty that you describe with dialog intelligibility I suspect has to do with how the two-channel downmix was done. In creating a two-channel soundtrack, the options are to either 1) create a dedicated two-channel mix and 5.1 mix separately from the multitrack master, or 2) downmix to two channels from a 5.1 soundtrack.

A dedicated two-channel mix is intended for playback through two speakers or through a Dolby Pro Logic setup. In general, this is preferable for those types of systems because the mix was done while monitored through that type of setup.

The 5.1 downmix to two channels basically takes a soundtrack originally mixed and monitored for discrete 5.1 playback, and downmixes everything using preset levels. This approach is easier because only one soundtrack needs to be created. However, this also creates problems with two channel playback because the downmix process is not at any point checked for how it actually sounds through two speakers. How it sounds with a two-channel setup is hit or miss.

You can easily check how different these soundtracks can sound by comparing 2.0 and 5.1 soundtracks on DVDs that provide both types of soundtracks. Listen to both soundtracks through the two-channel analog outputs on the DVD player. Very often, the dialog is much more pronounced on the 2.0 mix than on a downmixed 5.1 playback. This is because if the background sounds get mixed into both the front and surround channels, the mixdown process will actually blend the surround channels into the front channels at roughly 67% of the original levels. If the dialog/center channel is only anchored to the front, then those background elements can easily drown out everything else.

I've noticed that this happens with some movies that are simulcast in HD and 5.1. This leads me to believe that the two-channel audio feeds on those broadcasts are nothing more than default 5.1 mixdowns with no consideration given to how it would sound on a two-channel system. It's basically the cheap and lazy approach.

The suggestions to use five-channel stereo or DPLII come down to preference, but they won't fix audio problems with a two-channel mixdown from 5.1.

[JoeE SP9]

OK, there's apparently some confusion on my part here! I was thinking that I had to use the HD5.1 (digital) audio signal to get center channel dialog, but I forgot that same info can be obtained thru the analog side using the 2-channel signal and Dolby Pro Logic. Am I correct in that assumption?

You are correct sir!:ihih:

[radioflier]

Thanks to everyone that has responded. It's been years since I've paid attention to what was going on in the audio world, and I find myself way behind the curve here. Reading these forums and other info on the net has helped me catch up on what has been going on and where we are currently.

ron