Dolby Digital, DTS, Pro Logic II, and the Denon 2802 (1 Viewer)

[Michael Reuben]

Are you referring to this quote:

i was just told that "Stereo" separates the audio into left and right channels, but "Direct" puts all the music through both speakers.

I didn't comment on it, because I can't make any sense out of it.

M.

 

[Mike Matthews]

yeah, that's the one. when i asked a buddy, he just told me that in the Stereo setting, the music is split between the right and left channel. but with Direct mode, the same thing is coming out of each speaker...with no split

 

[Michael Reuben]

I don't have a Denon receiver, but that description (a) makes no sense, (b) is inconsistent with the operation of any "direct" setting I've ever experienced, and (c) is directly contradicted above by someone who has a receiver almost identical to yours.

But instead of shopping around for more opinions, why not try running your own test? Play a stereo CD in direct mode, and see whether "the same thing" comes out of both speakers. Then, in direct mode, try adjusting the bass and treble controls, and see whether they make any difference. Repeat in stereo mode.

M.

 

[Mike Matthews]

i've been trying to experiment with the Pro Logic II feature...but i only seem to be getting sound from the center channel when i'm watching tv in Pro Logic II mode. then i watched a movie tonite, and i was checking out some of the special features and noticed that the Digital light was lit when i was in Pro Logic II mode. then i realized that if i was actually getting a Dolby signal from a television program, the Digital light would have to come on. so now i know that when i watch tv in Pro Logic II and the Digital light isn't lit, then the program isn't encoded with Dolby Digital.

does that make sense? sorry, but i'm still new to all this and these are the little things that manuals and FAQs don't answer...

one last question. just out of curiosity, do you all prefer to watch the special features (the non dolby digital or dts parts of the dvd) in Pro Logic II mode, or Stereo mode, or Direct mode, or what? i was flipping through them...and i think i liked Pro Logic, just cause it at least simulated surround sound...but i was just wondering how other people do it.

thanks

 

[Michael Reuben]

Mike, I've merged your two threads on the features of your receiver and retitled the combined thread. I'm also moving the thread to the Receivers section. If you have further questions about how your receiver treats audio formats, please ask them in this thread. Do not start new ones.

DPL2 works with both analog and digital sources. So using DPL2 has nothing to do with whether the digital light is on.

then i realized that if i was actually getting a Dolby signal from a television program, the Digital light would have to come on. so now i know that when i watch tv in Pro Logic II and the Digital light isn't lit, then the program isn't encoded with Dolby Digital.

A simpler way to look at it: Do you have a digital connection from a TV source (cable box, satellite receiver, etc.) to your receiver? If so, you'll get a digital audio signal; if not, you won't.

M.

 

[FeisalK]

If you're interested in the results of one set of "blind test" comparisons between them, check out this thread in the Software Archive.

Michael thanks for the link - it made great reading and for the first few posts before Roogs came back and actually answered the questions I felt like I was seeing the birth of a myth unfolding before my eyes. Maybe he shouldn't have

 

[Mike Matthews]

one last question. just out of curiosity, do you all prefer to watch the special features (the non dolby digital or dts parts of the dvd) in Pro Logic II mode, or Stereo mode, or Direct mode, or what? i was flipping through them...and i think i liked Pro Logic, just cause it at least simulated surround sound...but i was just wondering how other people do it.

PS - i think i'm giving up on DPL2 for tv viewing! it's just not working for me. all the audio comes from the center channel. boo.

 

[Chuck Kent]

Mike: A quick reply re: Stereo vs. Direct for the 2802...

Stereo: Tone controls can be engaged or bypassed. If the mains are set as "Small" in the speaker setup menu, they are "Small" in Stereo mode. (Note, if the speakers are set as "Small", the sub MUST be used.) If the signal is analog, the mains are analog all the way but the sub's filtering is digitized. So, the biggest part of the signal remains analog all the way. Digital signals stay digital for all filtering but are converted back to analog just before the tone control section (and volume control of course.)

Direct: Can be used with or without the sub (the sub can be turned off separately just for Direct mode if it's not wanted.), Tone controls cannot be engaged and are always bypassed. The mains ALWAYS receive a fullrange signal, even if the mains are set as "Small" in the speaker setup menu. If the sub is used, the sub's lowpass filter is digitized, even if the incoming signal is analog. As with Stereo, analog signals in Direct mode remain analog (except for the sub as noted above.) Digital 2 channel in Direct is similar to analog in that it is fullrange and bypasses the tone controls and the sub can be used or turned off.

In both modes, 2 channel remains 2 channel. Nothing is "blended" (my word.)

Hope this helps some.

BTW, the quality of DPL II decoding depends a ton on how good the incoming signal is. If it's pretty much mono, then you won't get much beyond all center channel. In my case, DPL II is indipensable for 2 channel TV. I use it 100% of the time...

 

[Mike Matthews]

Chuck - i appreciate the reply. couple questions, though...

- what exactly do you mean when you say that if the speakers are small in the speaker setup menu, they'll be small in Stereo mode? i have my speakers set to small, but i'm not sure what it means to "be small in Stereo mode"

- i guess i'm having the most trouble figuring out what the difference is between a "fullrange" signal and an "analog" signal. i'm not sure how all the filtering works...but i know that my CD and DVD player are connected to the receiver through digital connections (optical cables) and the tv is connected with an S Video cable and when i watch tv, the receiver says "Analog." no clue what that all means, though

- i understand that with Stereo, you can use tone controls to change the bass and treble settings...whereas Direct mode bypasses this. when it all comes down to it, i can't tell a difference between Direct and Stereo when i listen...but which is supposed to be the better mode for music and television watching?


-- also...do you think it's a bit strange that NONE of my cable channels will work with DPL2? shouldn't at least some shows work?

 

[FeisalK]

Mike,

fullrange vs digital

on a CD for example, the signal is digitally encoded and includes the full audio spectrum i.e. form 20Hz to 20kHz. this is passed to a Digital to Analog Converter (DAC) which converts the digital signal to analog signals. This is a full range analog signal. Generally in a stereo amplifier the full range analog signal gets amplified and sent to the speakers.

Now, in a receiver and system with a subwoofer, you can sort of break the signal up and say signals up to 100Hz goes to the subwoofer and above 100Hz goes to the speakers. This could happen in the digital domain (done by the DAC) or in the analog domain (a "crossover"). the resultant analog signals are then NOT full range.

Of course the signal once at the speakers gets chopped up again - this time by an analog crossover in the speaker - that sends the midrange frequencies to the woofer and the higher frequencies to the tweeter.

hope this was helpful..

 

[Chuck Kent]

Mike: A couple of things that may help...

When we're talking about a digital signal, we're talking about the ones and zeros encoded on the CDs and DVDs we play. But as such (1's & 0's) they need to be decoded back into analog, which is what we hear coming from the speakers. Digital-to-analog converters (DAC's) are used for this purpose. Analog signals are what we need to have in order to hear the signal as music/movies (or whatever.) Analog signals can be converted to digital by analog-to-digital converters (ADC's) if there is a need to do so.

When we're talking fullrange signals, as Feisal notes, we're talking about the entire audible spectrum. From lowest bass to the highest human heard sound (although many of us have a hard time hearing the higher stuff due to hearing loss.) Fullrange can be either digital or analog.

When I mentioned filtering, all I'm really talking about is splitting (separating) the lower bass and the stuff above the lower bass. This is what is happening in your setup when you have the speakers set to small and use a subwoofer in your setup. There are 2 kinds of filters used. Highpass and lowpass. Each does just what you think they would. A highpass passes high frequencies and filters out the lower ones. A lowpass passes lower frequencies and filters out the higher ones. So, a highpass filter is used on the speakers you have set as small (filters out the bass) and a lowpass filter is used on the sub so that it gets the bass but filters out the highs. Using these filters sends the right frequencies to the best speaker for each type of frequency. Bass to the sub and the higher stuff to the rest of the speakers. (BTW, these filters are not brickwall type fliters. There is some overlap. Not a lot but some...)

Hopefully, this helps to make my earlier comments a little clearer...

On to your questions

If you have your speakers set to small (highpass filtered), they are still filtered in Stereo mode too. In Direct, the filter is not used and they receive everything, low bass and all.

I kinda already touched on your 2nd question. As you already know, the CD and DVD are connected digitally. Obviously, the TV sound does not come into your Denon as digital (1's & 0's) but as regular analog. Thus the 2802 saying analog.

If my comments in this reply help, try re-reading my earlier post. Direct mode bypasses both the tone control circuits and the main speaker's highpass filtering (that is already engaged by you thru the main setup menu.) So, since Direct is a straighter path, it would be the cleanest, clearest mode for 2 channel listening. But it is worth pointing out that if your speakers are better off not playing low bass (and most aren't), then Stereo might sound better in your case.

Finally, yes, I find it very strange that you're not getting decent surround from TV. Can you describe how your cable is hooked up and how (list the components used) the signal goes from the cable wall outlet to the receiver? Maybe something can be adjusted or changed to help with this situation.

 

[Mike Matthews]

ahh, ok. interesting. so do you prefer to listen in Direct or Stereo?

 

[Chuck Kent]

I run my 3803 Denon into an external 5 channel amp. Between them, I have an Outlaw ICBM connected. The ICBM does the highpass/lowpass filtering in my setup. So, because of the ICBM, I have the speakers in my 3803 all set as large. So Stereo and Direct are essentially the same pathways. In my setup, I can't tell any difference...

In your case, depending how well your speakers handle the lower bass, Direct may or may not sound better (even though it is a simpler, straighter sonic pathway.) Many systems sound better if the mains are highpass filtered and the sub picks up the rest...

 

[steve nn]

I think in this conversation I have possibly found my answer to a little problem I have been having.

I picked up a Denon 1804 on friday and am in the process of setting it up. I love the sound and the ability it seems to have but in calibrating I have to adjust individual speakers in the test tone option and then back on over to my calibration disk to see if I need to go +- . I know this is the long way of doing things but my individual speaker settings seem to have been neutralized. Any adjustment made to them in calibration with a calibration disk has no affect unless I go on over to the test tone function and adjust and then come back over to the disk and see the affect. I have the tone control set to yes in the set-up menu and I am running DVD direct coax. I know this will be a easy fix once I figure it out but maybe a more knowledgeable person could give me a quick answer?

Thanks for letting me step in Mike.

Disregard my question. I really don't know what I had wrong? I think it was the input mode? I am still familiarizing myself with the 1804 and I have the individual settings working just fine now with out having to go into tone control.

 

[Geoff L]

Hi Mike

Regarding you not getting sound out of other channels, ~{except for the Center when using DPL-II}~, could be a number of reasons.

The 2-channel source material possibly, but not likely, more likely, your calibration settings (small large and volumes) in the receivers set-up menu.

Most of the newer AV-Receivers require you to set channels volumes (for three separate sources at "least")....
That woud be, DTS, DD, & DPLogic!

This has been the case in the last "3 different brand Receivers", no Denon's tho, we have purchased.

If you have not calibrated your speaker & sub volumes & small large settings for (DPL) in the Denon's set-up menu, this could be a reason why when you select (DPL-II) and listening to TV sources, the other channels seem never to be active.

I am NOT familar with any of the Denon AV-Receivers, but would assume they operate similar to other AV-Receivers in this regard. In the Denon's manual it should mention what seperate modes (DTS, DD, DPL, etc,) you have to calibrate to get proper sound movement.
Something you might check into.

Don't know if this helps, but seems odd that when listening, watching your TV, that all analog 2-channel stuff comes "only" threw the Center.

======>
What happens when you get a TV DPL analog signal, is it the same, all out of the Center?????
======>

My guess would be that is what happens. So DPL-II would certainly follow the same, more than likely. :frowning:

Regards
Geoff

 

[Mike Matthews]

thanks for all the replies, everyone. i'm still working on the DPL2 issue, but i definitely have a much better understanding of stereo, direct, fulrange, anaog, etc...!

 

[Cagri]

i think i'm giving up on DPL2 for tv viewing! it's just not working for me. all the audio comes from the center channel. boo.

Consult your manual and you'll see that somewhere in the setup menu of your receiver there's a "width" setting. Denon receivers come with a setting where in DPLII the sound is only coming from the center channel, but you can adjust it by increasing the "width" setting, literally widening the sound to the left and right mains as well as the surrounds.

 

[Mike Matthews]

i actually saw that and thought it'd fix my problem...but it only works for the DPL2 MUSIC mode. not sure why...

 

[Cagri]

If that's DPLII cinema mode you're trying to get surround sound, I guess you can't do that. Somehow the receiver only feeds the center channel in the cinema mode. Fix the widht and use the DPLII music mode, it doesn't matter that it says music it's still DPLII. I have to say I'm not too much impressed by it by the way. I can't tell any significant difference between especially 5 channel stereo and DPLII.

 

[Mike Matthews]

hmm - i'll definitely try that. i know about the width feature, but i didn't realize that i could have it set to music mode and have it still work for tv. roommates are asleep now, so i'll try it tomorrow. there was an HBO movie on tonite and it said at the beginning it was presented in 5.1 - and sure enough, i switched to DPL2 and it only came through the center channel. ended up watching it in 5 channel stereo and it sounded fine.

also - is it possible that maybe i can't watch tv with DPL2 because of the type of cable i have? is it possible that they just don't broadcast in surround, even though certain shows and stations do?