Film-Tech Forum ARCHIVE: Sound Format Differences?

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Posted by Claude S. Ayakawa (Member # 1401) on 01-19-2009, 06:34 PM:

I have been using a Denon AVR 3802 receiver that t has been serving me very well these past couple of years. I now have a Panasonic model DMP-BD35 Blue-Ray disc player and has hooked up the player to the Denon. The Denon has a sound input for only 6.1 but the Blue-Ray has a 7.1 sound output. The Panasonic has a built in decoder for both Dolby TrueHD as well as DTSHD Master Audio and because the Denon does not have a HDMI input and can play sound up to only 6.1, what kind of sound is reproduced by my receiver when I play BD's with the new sound formats that come with the HD discs? Am I getting better sound than regular DVds or is the BD player sending scaled down 5.1 to my Denon receiver? I do not think I am getting scaled down sound because as I had mentioned in another thread, the sound I hear from BD is fuller with an occasional clipping I hear once in a while when the volume is a little high; I asked this question in another thread because the clipping sound is the only thing that is troubling me. Is there something I need to do either with my BD player or my receiver to correct this problem?

-Claude

Posted by Bobby Henderson (Member # 840) on 01-19-2009, 07:30 PM:

This is something I've been wondering about since my father has the same kind of AV receiver.

With the 7.1 format you have stereo back wall surround channels while the 6.1 format has the back wall defined as one mono surround. Is there a "Y" adapter you could get from Radio Shack to combine the two analog leads into down to one mono cable or will that cause some problems?

Couldn't tell you about the clipping problem. Is it happening in all speaker channels or just a specific one? Does the clipping occur in the exact same place in the movie? As a general trouble-shooting rule, check all your cable connections. If the clipping is only coming from one speaker you could have a loose connection or damaged cable or even a speaker driver that's on the fritz.

Have the BD player check the Internet for firmware updates in case the internal DD/DTS decoders need improvement. Sony's Playstation 3 has gone through a couple generations of improvements on its internal Dolby TrueHD and DTS-HD decoding.

Posted by Scott Jentsch (Member # 1681) on 01-19-2009, 09:09 PM:

I checked the manual for the DMP-BD35, and on page 8, it gives a chart for what will be sent through the various audio output options you have.

If I understand the chart correctly, if you have the digital audio output set to "bitstream" you will get the following through the optical digital audio output with the corresponding soundtrack format:

Dolby Digital: Dolby Digital

Dolby Digital EX: Dolby Digital EX

Dolby Digital Plus: Dolby Digital

Dolby TrueHD: Dolby Digital

DTS Digital Surround: DTS Digital Surround

DTS-ES: DTS-ES

DTS-HD High Resolution Audio: DTS Digital Surround

DTS-HD Master Audio: DTS Digital Surround

7.1ch LPCM: Downmixed 2ch PCM

As far as the clipping goes, that sounds like something you'll want to figure out. If it is clipping, it's going to hurt your speakers eventually (and maybe your amp as well). The problem is, I can't think of anything that you can do to fix it yourself. I've not heard of any players that have variable output levels on digital audio outputs, so that leaves the input level adjustments (if any) on your receiver.

Have you tried changing the optical cable with a different one?

How about trying a different input on the receiver?

Have you eliminated the source material as a possibility? i.e. have you tried a variety of music and/or movies and seen any pattern to the problem?

Posted by Bobby Henderson (Member # 840) on 01-19-2009, 09:54 PM:

At first I thought Claude was sending converted to analog audio via line out leads from the BD player. However, the DMP-BD35 doesn't feature multichannel analog output (while the $100 more expensive DMP-BD55 does).

Still, there could be a problem with the audio cable used between the BD player and the receiver. I'd try a coaxial cable or a spare fiber optic cable just to rule out the current audio cable in use.

There could also still be some issue in BD player firmware. The DMP-BD35 is a BD Live model with LAN connection. Check for updates.

Posted by Joe Tommassello (Member # 4632) on 01-20-2009, 04:50 PM:

I am not sure if this is a universal feature but my LG Blu-ray player has an option to output all multi-channel BR disc soundtracks as DTS. An example of it's usefulness is that a Dolby TrueHD track will take advantage of DTS' higher bitrate rather than the more limited Dolby Digital bitrate. There is a very noticeable difference between the two and it will suit me just fine till I decide to upgrade to a new receiver. It even works with uncompressed PCM tracks as I discovered with my import copy of "The Producers".

Claude - you may want to look for an "output as DTS" option in your Blu-ray deck's audio setup.

Posted by Claude S. Ayakawa (Member # 1401) on 01-21-2009, 06:35 PM:

I seem to have no problem with clipping when I play regular dvds. I also had no problem when I played the first fifteen minutes of ERNEST SCISSORHANDS, THE NOTEBOOK, INDEPENDENCE DAY, and the History Channe's l GETTYSBURG/GETTYSBURG ADDRESS on Blue Ray last night. The discs so far that has caused problems with clipping was "BARAKA, SLEEPING BEAUTY, BATMAN BEGINS and HOW THE WEST WAS WON. The most severe case of clipping occurred just after I hooked up my new BD player to my home theatre system when I decided to test the player with the Smilebox version of HOW THE WEST WAS WON. Everything was fine at first and than the sound clipping occured during the end of the overture and with the exception of my rear speaker, there was so sound from all of the other speakers. There was a tremendous sense something terrible had happened to all my speakers but when I played with the dials on my receiver, the speakers were all functioning again. After that experience, there would be slight clipping when I play the above mentioned discs but nothing serious. If I continue to experience clipping, I will chack my cables, Bobby. I will also check the DTS output on my player, Joe.

Speaking about DTS, I have notice that there are many titles in BD that have DTS tracks when the regular DVD of the movie did not. This is one of the reason I love Blue-Ray and decided to switch over. When DTS was first used on DVDs, they were encoded with the full 1,536 kbt with a standard pro logic Dolby track but when discs came out with Dolby 5.1 tracks with the DTS, they cut back on the DTS bit rate to half at 768 kbt. Because Blue Ray has a much larger storage capacity, is the storage space the full bit rate for for regular DTS playback with my current Denon receiver that does not have a HDMI or a 7.1 input?

-Claude

Posted by Mike Blakesley (Member # 26) on 01-21-2009, 06:40 PM:

quote: Claude S. Ayakawa
ERNEST SCISSORHANDS

Must be a sequel, eh?

Posted by Claude S. Ayakawa (Member # 1401) on 01-21-2009, 06:45 PM:

My mistake, I meant EDWARD SCISSORHAND. [Smile]

-Claude

Posted by Bobby Henderson (Member # 840) on 01-21-2009, 07:34 PM:

quote: Claude S. Ayakawa
Because Blue Ray has a much larger storage capacity, is the storage space the full bit rate for for regular DTS playback with my current Denon receiver that does not have a HDMI or a 7.1 input?

Just about any movie on Blu-ray with a DTS-HD track will output a "full bit rate" 1509kb/s DTS lossy "core" track that is backward compatible with older receivers.

There may be a couple of import discs with an odd 754kb/s DTS lossy track, but those are the exception and not the rule. Generally, lossless audio rules the roost on Blu-ray. The DTS-HD Master Audio tracks all feature backward compatible "core" tracks.

The Dolby TrueHD tracks on Blu-ray tend to behave the same way as DTS-HD Master Audio, although the maximum bit rate 640kb/s Dolby Digital tracks are not embedded inside the Dolby TrueHD code. They're stored alongside as a companion track and merely just not shown in the movie's audio setup menu. The Blu-ray player knows to select the DD track if the player is sending audio out of a standard optical or coaxial audio output.

Claude, from what you have described I think there's something going on with your Blu-ray player. Have it check the Internet for a firmware update. If that doesn't solve the clipping problem try swapping the audio cables attaching the player to the receiver. Try coaxial versus optical if you have the option available.

Posted by Claude S. Ayakawa (Member # 1401) on 01-21-2009, 08:41 PM:

Bobby,

I just talked to my friend at the store I bought my Denon receiver and he told me that there is a possibility that because of it's age it cannot handle the dynamic range of Blue-Ray sound. Steve told me to play the discs I had a problem with cllipping at a lower volume and if the speakers does not clip, my receiver could be the cause of the problem for the above mentioned reason. Because DVDs have a much lower dynamic range, that is the reason they play without clipping, according to my friend. I will do some more testing tonight and hope I can solve the problem I am having.

-Claude

Posted by Bobby Henderson (Member # 840) on 01-21-2009, 10:41 PM:

I don't think the salesman's comments make sense.

The new lossless formats (Dolby TrueHD and DTS-HD) don't have dynamic range any wider than their previous lossy compressed counterparts. They're only improving the amount of detail capable of being recorded into the audio track, not increasing the extreme highs and lows of it.

Another part that doesn't make sense is the Blu-ray player is still only giving your Denon receiver the same old lossy format audio tracks. There's not all that much different about them and the lossy tracks found on DVD, other than the DD 5.1 tracks are typically 640kb/s rather than the 448kb/s or 384kb/s rates found on DVD as well as DTS tracks being 1509kb/s instead of the 754kb/s variety found on DVD.

I still think it's worth making the BD player check the Internet for a firmware update. When my PS3 was new right out of the box it had at least a couple audio glitches, including a lip sync problem with DTS tracks on DVDs. After applying that first system software update the DTS glitch was fixed. The PS3 has had at least half a dozen firmware updates over the last year.

Hopefully there isn't something mechanically wrong with your Denon receiver. One friend of mine had to get rid of his old Pioneer receiver when its 5.1 functions (particularly its ability to decode Dolby Digital) disappeared. It only worked in basic stereo. He replaced it with a HDMI-equipped Denon receiver featuring Dolby TrueHD and DTS-HD decoding for about $900.

Posted by Tom Mundell (Member # 4555) on 01-22-2009, 11:08 AM:

Claude,
I don't think you should have any problems with audio playback with that Denon. I'm using the Denon AVR 3802 with a Panasonic DMP-BD10a, and so far haven't had any problems with clipping via DD or DTS via the optical connection. I also have the analog outputs connected for Dolby TrueHD playback which works fine too.

Bobby, when you say the 5.1 functions disappeared, you mean the 5.1 playback died altogether, or just didn't work with blu-ray? I have encountered no 5.1 audio over optical with the DMP-BD35 (dts or dolby digital) when play blu-ray discs; dvd works fine. After much searching the conclusion was the receiver being used couldn't handle the higher bit rates for DD and DTS (wish I knew if that was correct and why full bit rate DTS seems to work fine on dvd). (this was with a B&K Reference 50) I think the BD-35 does have analog output (but only 5.1, and it just decodes regular DD and DTS, not the HD formats) - that's what we used to get around the optical cable not working.

Posted by Bobby Henderson (Member # 840) on 01-22-2009, 02:04 PM:

quote: Tom Mundell
Bobby, when you say the 5.1 functions disappeared, you mean the 5.1 playback died altogether, or just didn't work with blu-ray?

I was talking about a friend's previous DVD and receiver setup -both Pioneer models. This was before he bought a PS3 and a Denon receiver. The DVD player still works fine; it's one of those models that includes a lot of Karaoke functions. The receiver simply stopped working in 5.1 altogether. It didn't matter on the 5.1 source, be it HBO via digital satellite or DVD movies. The receiver would still play CDs and other audio in stereo. It just would wouldn't do anymore 5.1. Obviously a hardware issue in the receiver.

Posted by Claude S. Ayakawa (Member # 1401) on 01-23-2009, 03:26 PM:

As I had mentioned in Julie's thread, my speakers has not been clipping at all during the past two nights. I watched the Meg Ryan & William Macy film THE DEAL on Wednesday night and the football film THE EXPRESS about Ernie Davis last night both on Blue-Ray discs and my speakers never clipped at all even after I had the volume at a slightly higher level. I guess this clearly indicates my friend at the audio store did not know what he was talking about.

There is one thing I have notice about Blue-Ray discs is the tremendous improvement in sound quality I am getting from my sound system. Although I am not set up for DTS HD Master Audio or Dolby Digital True HD, the sound from BD and even regular DVDs sound like I have a totally new system. One of the things I have noticed is how active my rear speaker is now compared to the very subtle way it had sounded before. During a couple of scenes especially the football games, all of my six speakers and sub woofer was all pumped up when I watched THE EXPRESS.

-Claude

Posted by Claude S. Ayakawa (Member # 1401) on 01-30-2009, 03:45 PM:

I am once again having problems with clipping but strangely it occurs only when I play discs from Warner Brothers Home Video. HOW THE WEST WAS WON and JOURNEY TO THE CENTRE OF THE EARTH (New Line) are two that I had noticed that has been causing the problem. I heard slight clipping in the beginning when I first played the BDs of BARAKA and SLEEPING BEAUTY. No clipping so far on the BDs that I have been renting from Blockbuster or Universal discs such as KING KONG, and others.

I talked to Panasonic Support this morning and I was asked if "Bit Stream" was selected in the audio menu instead of PCM. Does this sound right? Do you know what setting is on the player when it comes out of the box?

-Claude

Posted by Tom Mundell (Member # 4555) on 02-01-2009, 09:43 PM:

quote: Claude S. Ayakawa
Do you know what setting is on the player when it comes out of the box?

My memory is a little hazy on this so I'm not 100% sure, but I believe my BD-10a as well as the BD-35 both had bitstream as the default.

Annoyingly I'm wondering if I came across this or similar problem; my copy of Hell Boy 2 has a horrendous amount of clipping playing over the analog outputs; optical is fine (though it's much louder than any other movie I own, no distortion or clipping is present). This is the only disc I've had a problem with so far.

Posted by Claude S. Ayakawa (Member # 1401) on 02-03-2009, 03:04 PM:

I am still having a problem with clipping but with only HOW THE WEST WAS WON and JOURNEY TO THE CENTRE OF THE EARTH.My BD of BARAKA caused clipping when I first played the disc when after I had set up my player to my home system but everything is fine now when I play it. All other BDs play fine without any problems including the new ones I rent from Blockbuster.

-Claude

Posted by Joe Tommassello (Member # 4632) on 02-03-2009, 03:18 PM:

Claude:

Is it possible you are overdriving your speakers?