True story:
Back when the "Live Licks" 'Stones DVD set was being mixed in surround, a test mix was sent to Mick Jagger's house in the Loire Valley in France for him to audition.

He responded with an "atrocious".

One of the mixers flew from LA to France, only to find that Mick was listening to the front two channels played through Dolby Pro-Logic, so that he was only hearing 2/5 of the mix being re-processed to feed all 5 speakers.

That's the Mick Jagger Syndrome.

My big question to you guys is:
1 -- if you attempt to play a Dolby Digital DVD, does your system allow you to use subsequent "room processing" -- delays or other stuff like Pro-Logic or "Live house" or other processing -- or does your system do what Dolby standard processing specifies, and defeat all that stuff and let you hear the 5.1 channels the way that they were originally mixed?

2 -- same for DTS discs?

3 -- Bass handling. Dolby mix guidelines say that no bass should go into the LFE channel for music. LFE use is reserved specifically for earthquakes, explosions, etc. in motion picture use. (If you were to download the short DTS bass test CD that is in my other thread (Penteo test for you to try) you might be able to answer easier, but I'll ask regardless)

a. Do you prefer bass -- in music -- to be specifically directed toward your LFE (subwoofer) channel?
b. Would you prefer that all bass be kept in the 5 surround channels and not explicitly directed toward the LFE channel?
c. For those of you who have small speakers in the 5 channels and depend on the subwoofer for all bass --
does your system grab bass from the 5 surround channels and direct them to your subwoofer -- or does your system (especially on Dolby Digital and DTS material) only put the LFE channel into the subwoofer, leaving the 5 surround channels essentially bassless?

This has long been an unresolved set of issues with equipment manufacturers. Also, for consumers with disc players which are separate from the preamp, there's no signalling between the disc player and the preamp to defeat all processing when a DTS or Dolby Digital disc (DVD) is inserted.

By all rights, there should have been a separate signal (ultrasonic?) that tells the receiver to disable all room processing and send the left front to the left front, the right front to the right front, the center to the center, the left rear to the left rear, the right rear to the right rear, the LFE to the LFE, and then -- if there is bass management to divert the 5 surround channels' bass into the sub, do that, but that's all.

But it never was done that way, so it's always up to the listener to get up and turn all that crap off manually, just so that you can hear how it was originally mixed.

I know it's a lot of questions, but since I can't go around and test every consumer system personally, your feedback really helps.

By the way: the way it's SUPPOSED to work is:
1: If you insert a Dolby Digital or DTS disc (or select that on a DVD), you are not supposed to be able to change or modify the room parameters. They are supposed to be "hard locked" so that you get the same experience as on the mix stage.
Bass handling is the one exception, since not all home systems have full range speakers all around, and almost no one has a full range center, simply for space issues. Bass is supposed to be directed from the 5 surround channels into the subwoofer in those cases.

The big issue with surround music is that bass guitar and kick drum -- the two instruments which provide all the bass in a popular music mix -- are always dead center. Since we know that almost no one has a full-range center speaker, we have to do something with it. We either have to put it in the sides or the LFE (subwoofer) channel. We then have to decide whether or not to leave it in the center.

ARRRGGGGHHHH!!

Now you understand why it's so difficult -- even on the mixing end...


Thanks again,

=John

John,

May I suggest that you not bass manage the recording itself when you're mixing it. If the bass guitar and kick drum are "always dead center", then place those sounds in the centre channel.

Upon playback, if someone does have a full range centre speaker, then all the sound will come from there. If the centre speaker is small, then the lower non-directional frequencies will be re-routed by the bass management system to larger left & right speakers and/or subwoofer. The more directional frequencies will stay in the centre speaker so that those sounds continue to image "dead center" of the soundstage, while their impact is felt from the larger speakers and subwoofer.

If you feel that the impact in the recording isn't enough, then you can copy the lowest frequencies (e.g., below 120Hz) to the discrete LFE channel for additional bass slam.

Since you don't know what the listener's playback system is going to be like, no sense in imposing pre-concieved limitations on your mix. Second guessing will just compromise your recording.

Sanjay

John, May I suggest that you not bass manage the recording itself when you're mixing it. If the bass guitar and kick drum are "always dead center", then place those sounds in the centre channel.

Hey Sanjay, thanks.

Actually Penteo doesn't separate sounds out except based on pan-pot position, so all of the bass sounds are in the center channel regardless.

I only hope that everyone out there has their bass management set up for it, otherwise there's no bass if they don't have full range centers.

Dolby mix guidelines say that no music - ever - should be put into the LFE channels, and that there should never be a dependency on the LFE channel for bass. All surround mixes of music, therefore, are supposed to actually be 5.0, with nothing but zeros coming along for the ride in the LFE channel -- depending on the consumer to set the bass management on their end.

My bigger concern is that "Mick Jagger" syndrome. When I go into a retail store to play a Penteo disc for auditioning in there, it's amazing to me how -- even here in the educated San Francisco area -- many retailers don't know how to play a true 5.1 disc in true 5.1. They have spent so much time playing back stereo -- through DPLII -- that they think somehow that that is 5.1.

Those of you who have heard any demos know that they start off with a channel ID series. You'd be amazed how many times the only two channels that show up are "Front Left" and "Front Right" -- but spread out around the room... :-(
=John

Penteo doesn't separate sounds out except based on pan-pot position, so all of the bass sounds are in the center channel regardless.That's good. I only hope that everyone out there has their bass management set up for it, otherwise there's no bass if they don't have full range centers.If you're worried about it, bleed a little summed bass into the LFE channel. For example: Alan Parsons' quad mix of 'Dark Side of the Moon' that's been floating around the 'net has a .1 channel that didn't exist in the original 4.0 mix. Dolby mix guidelines say that no music - ever - should be put into the LFE channels, and that there should never be a dependency on the LFE channel for bass.Their concern is probably based on the fact that the LFE channel is discarded when players downmix the soundtrack to 2 channels using Dolby Surround encoding. I agree that the soundtrack shouldn't be dependent on the LFE channel for all the bass, but I don't think anyone follows the rest of the guideline. And it is just a guideline after all, not a hard & fast rule of mixing. Practically every multi-channel music title I own has some content in the LFE channel.

Sanjay

To answer the OP's question regarding setup, here is how I have it:

My speakers are all set to small (no full range speakers in my system). The crossover is 80hz (works best with the speakers and sub I have). My receiver does not allow me to change any parameters for DTS/DD 5.1 material (any 6.1 material, of which I have very little, is dealt with in a manner with which I'm not familiar-I presume the 6.1 metadata contains a 5.1 mix within it, but I have no idea if I'm right).

I apply no other room correction at the receiver (not an available feature). I do have a digital parametric EQ to flatten bass response, but that should not be a factor as it is applying itself to the bass signal AFTER it has left the receiver--so it is only treating the bass that is directed to the sub by DD/DTS.

For music, I have two players. One is configured in 2.1 mode with an 80hz crossover internally and that signal is sent to my receiver's MCH analogue input and played back in "pure audio" mode--no other processing is involved (this player is for CD playback). The other is a hi-res audio player which sends a full range signal (no bass management and time alignment is done in the player) to my receiver where the MCH analogue input receives the signal and, by engaging bass management and time alignment for the MCH analogue input (an A/D process), the receiver applies ONLY the crossover and speaker delay--it does not allow any other processing of the signal.

I have no complaints about the sound quality (I don't find I get excessive or thin bass, for example) and everything seems to work appropriately. I NEVER mistake ProLogic or Neo:6 for "the real thing" as I am quite careful about my input settings.

Hope this helps.

My receiver does not allow me to change any parameters for DTS/DD 5.1 material.

You have no idea how happy that makes me.


I NEVER mistake ProLogic or Neo:6 for "the real thing" as I am quite careful about my input settings.
You have no idea how uncommon you are. You honestly cannot imagine how many (I would guess >85%) of 5.1 receiver owners who are listening to what they think is 5.1 surround, but is just DPLII or the like.

It's very similar to (and very likely the same people) who go out and buy HDTV software, and then think that SDTV, stretched out wide, is HDTV. Actually, the analogy is strikingly similar. :-)

Actually, judging from the fiddling I do with my friends' set ups when I visit (they are part of the 85%), I'm quite aware (sadly, they manage to mess up my "fixes" between my visits). What can you do? :(