Why some DVD's are 5.1 but don't give the sub ( .1 )??

[chinets]

I have found many DVD's that are Doldy Digital 5.1 written on the disc or box or jacket such as "Diana Krall live in Montreal Jazz Festival " that states it's a 5.1 recording ,but when I get to play it on any DVD player Rotel or Sony etc. it will only give me the 5 Speakers but not the Sub woofer. In other words , it gives 5 but not the .1 sub part I am looking for...WHY????? and have you experienced that before. Check that DVD Video of Diana Krall and you'll get the drift. Anyone with answers please???? Have a great day!!!!!!!

[ajpoe]

I have read that some recordings, especially multichannel music, do not have a .1 track. This means in a multichannel music listening setup where all channels are large, the subwoofer isn't used. I guess most receivers/processors won't let you change the setup of the size of your speakers for multichannel music and that's where something like the Outlaw ICBM can help (this is where I actually read about these situations). I guess the label shouldn't say it's 5.1 when its really only 5.0...

I think this is the link to the review I read.

[csuzor]

For dolbydigital, options like "Subwoofer to Max", and for sacd/dvd-a, options like "LFE Redirect", on processors (in this case RSP-1068 ) make a merge of the bass from the other channels into the sub channel, so you don't miss anything if your speakers can't reproduce low frequencies.
I prefer not to have the music from any channel altered (such as a high pass filter with lower frequencies redirected to LFE channel), because then you are free to set your own crossover frequencies to match your speakers... LFE merged from several channels leads to phase errors, which is perhaps the reason why classical sacd rarely use the LFE.

[chinets]

Thanks Guys for your kind reply!! The DVD I was mentioning is a DVD-Video that won't give me 5.1 when it is marked very clearly on the box and cover of the DVD-Video that it is recorded in Dolby Digital 5.1 but only gave me the 5.0 and the Sub woofer was dormant. It wasn't a DVD-A or a SACD ,just a normal DVD-Video that I had that problem with. Any suggestions??? Thanks!!!!

[StefanColson]

Using the sub when mixing music (you mentioned it was a Diana Krall DVD, right?) can be a very tricky situation. Out of all variables when it comes to home theater rigs, sub level is probably at the top. As a mixer it's often best to avoid the dedicated LFE channel all together, rather than risk your mixes being screwed up and drastically different from system to system. The ultimate goal as a mix engineer is to get you mix sounding consistent from rig to rig.

[DrJRapp]

I think it was probably re-recorded using the 5.1 process, from some other format that doesn't have any LFE material on it.

[chinets]

DrJRapp you are probably right. However, it was an original recording of the Montreal Jazz fest ( Pretty NEW) , and it clearly stated 5.1 and it was playing on every DVD player on 5.0 how strange for them to state 5.1 when it is really is a 5.0 I thought for a moment that my Sub died ,but when I put another DVD all the 5.1 was there. Yes, Mr. Jerry ,you are I believe ,correct!!!!!!!

[jim777]

What would you want them to put on the .1 channel? A low-pass filtered version of the other channels? That's for you to decide and it's your processor's job (if you specifiy that your speakers are not full range). The LFE channel is more for "low frequency effects" and is more usefull for films (kaboooms) than for music. I even think that Dolby recommends not putting anything in the LFE channel for music.

Technically speaking, the stream is still 5.1 because there is still 6 channels on the DVD, even if the LFE is all zeros...

[chinets]

Jimm777 All My spaeakers are full range N803F and N804 R and HTM1 Center and SUB ASW 850. I did not specify the processor to do anything. All i did was put the DVD in and chose set up Surround 5.1 but it played back on all speakers but left the Sub dormant with no noise. However, when I changed the DVD to any other DVD and choose Surround 5.1 it gives me 5.1 and I never touched my processor at all???? That is why I asked that question??

[csuzor]

chinets, what is your processor?
It is probably setup for full range for all speakers, so it is not redirecting any low frequencies to the sub, but just playing the LFE channel. If you set your speakers to small, and cross-over at 40Hz (reasonable given your 803/804), then you will get low frequencies in the LFE all the time, whether the disk is 5.0 or 5.1 or the .1 channel is empty. Do you know how to change this setup?

[Andrew M Ward]

Set bass management to Max on Rotel or eBass on Classe' and the Preamplifier will handle this scenario correctly...

[chinets]

Thanks guys, My Amp. for the time being is the Rotel 1065 and no Mr. Csuzor I don't know how to change the settings. Could you guide me. All my speakers I know are set to Large speakers and crossover for Sub is 100. I tried to put the Sub from behind frequency and Volume to Max including the Set up to Max Db but it will not play that specific 5.1 DVD Video in 5.1 although any other DVD Video will play this immediately. It will get all my speakers working but the SUb(funny). The DVD in question is the " Diana Krall Live at Montreal Jazz Fest" and it specifically states on its cover and box etc 5.1 but I cannot get it to play it in 5.1 when any other DVD recordings plays 5.1 fine with me and had no problem..That was my question why this DVD when it is in perfect condition and an Original recording.???