DTS Master Audio...Uncompressed PCM...and a Whole Bunch of Headaches... - Page 2

You're kidding right... Throw in HD DVD Video Essentials and check out the TRUE HD 7.1 test tones... NOTE the .1 is LFE.

I am using a Halcro SSP 7.1 surround processor (accepts LPCM over HDMI). I can tell you that the sound is improved compared with DD / DTS but depending on the soundtrack type, is lower in level that the lossy counterpart. The bass is there in spades but the overall level is lower. I watched Seabiscuit the other day and had to watch at +6 (6 db over THX reference level). Regardless of the track, the bass is never absent - just over all volume level is decreased.

Oddly, I haven't noticed a difference on Blu Ray Uncompressed Soundtracks in overall level compared to DD nd DTS... only on the TRUE HD tracks is the overall level decreased.

With respect to LFE from LPCM tracks....it is there. I have a Sony BDP-S500 Blu-ray and a Toshiba XA2 HD-DVD both connected to a Yamaha RX-V861 used only as an audio processor (component video switching and digital audio switching handled by a Key Digital switcher). The S500 is connected to the Yamaha by HDMI with the player set to output only PCM (decodes True HD, DD+, DD, DTS and DTS HD). The XA2 is connected to the Yamaha through the 5.1 analogue inputs, so all decoding is done in the players. My coaxial output from both (as well as a dvd player) is sent to an outboard Marantz 870 DD decoder (I like the sound, though no DTS). The V-861 pre-amp outputs are connected to the Marantz 5.1 by-pass inputs and from there routed to separate amplifers for the various channels. All my speakers are full range and set to large with only the LFE signal (from all sources, except decoded Pro-logic signals) going to a Mirage BPS-400 sub. With this set up, all the LFE levels from all sources are more or less the same, no extra large boosts (the S500 has no level controls anyway) and all of the Yamaha levels are within a dB or so of each other. The Yamaha levels were set to match the output levels from the Marantz 870 decoder, so no changes needed to be made to the amplifier levels. I have no problems with LFE levels when testing (HD-DVE, DVE, Video Essentials and even laserdisc DD LFE when played through the Marantz). There is definately an LFE signal from both decoded DDTHD, etc as well as native LPCM from Blu-ray over HDMI as well as from the XA2 over analogue.

As for level differences between DD and the "high rez" tracks, I find it varies from title to title, with the only exception being DTS decoded tracks (DVD from the S500) tend to be generally louder. The PCM, DDTHD etc (from HD-DVD and Blu-ray) tracks are usually a bit lower in overall volume but the peaks are just as loud and the quiet passages quieter. The sound field placement is more defined as is the overall quality of the sound. I now find regular DD tracks "compressed" in range and having less "life" in the sound.

All of the above are just my own observations for my system and set up and might be different for other systems and equipment. Overall, no LFE problems have been encountered and the sound from the "high rez" tracks is definately superior to the regular DD DVD tracks. By the way, my reference levels (by HDDVE, VE, etc.) are approximately 71-72 dB (vs 75 dB) with the LFE level at about 75dB all by the Radio Shack meter.

Cheers, P.E.H.

Nope, not kidding. Let me clarify my statement a bit. The term "LFE" for low frequency effects is a product of Dolby Digital encoding. TrueHD is a Dolby Digital product and it contains an LFE channel, and when it is decoded into LPCM the "LFE" information is not stripped out. Alternatively, uncompressed native PCM tracks are not Dolby Digital products and do not contain an "LFE" channel per se. They may contain a dedicated bass channel or they may have all channels carry the full audio frequency. If it is the latter then the low frequencies are not being directed to the subwoofer, but rather to all of the speakers in the system. If your system is like most and you do not have speakers that can reproduce bass like a subwoofer, then you will not hear all of the available low frequency information in the recording unless you have a way to redirect it to the subwoofer. This is how SACD disks are recorded and you will find the same thing in some movie sound tracks.

It's all about bass management.

Here is an old but excellent article that explains the history behind the LFE channel: http://www.hometheaterhifi.com/volum...pril-2000.html

I understand that but most systems have adequate bass management. Simply telling your receiver your LCRs are small, will reroute the low frequenceies to the sub. However, the LFE is its own thing and is on a dedicated line. TRUE HD carries full range in all the 5 channels. I think you are talking about bass in those 5 channels. LFE bass is different as you know. It is its own channel separate from the other 5.0 full freq bass. Most all receivers reroute all full range LCR bass to the sub channel. So the sub channel is supplied with bass from the 5.0 channels + the .i LFE channel.

once more, turn the volume knob to the right.

it IS true that some (most? many?) do not handle the lfe channel "correctly" (i.e. add the 10 db boost that they should) over hdmi... this can be fixed by firmware updates in many cases...

Take a look at this online article, which might help answer some of your questions:

http://www.highdefdigest.com/news/show/1233

Simple. The parts to extend DTS into Lossless ("Master Audio") are simply ignored in your config. Pretend it doesn't exist and the disc only has DTS.

So, it shouldn't make a difference. One way, your BD player decodes the 1.5 Mbps "core" DTS into multi-channel PCM... the other way, it passes the 1.5 Mbps "core" DTS to your receiver for decoding. If everything is set identically (levels, processing, etc.), there should be no discernible difference.

There was no need for a new thread, please continue discussion here.

no, pcm over hdmi doesn't "reduce" lfe. it's sending it "correctly". some avr's do not apply the boost that they should when the channel is passed this way.

be glad there are firmware updates. they extend the life of your equipment.

Yup. OP would do well to read this thread: http://www.avsforum.com/avs-vb/showthread.php?t=748147 , esp the 1st post.

The best thing for you to do is to NOT buy any new modern A/V equipment. That way you won't have to worry about updates. You're looking at this whole update thing in entirely the wrong way. No sense in explaining it.

BTW, don't buy any satellite receivers or cable boxes. Don't get Tivo. Etc.

Also, I sure hope you don't accept the Windows updates or Mac updates to improve or secure your computer. Those updates are evil, aren't they? These darn computer companies should make their software perfect from the get go.

Blu Camry SE I find your responses to be completely frustrating. What I posted is correct it you bother to read it. "LFE" is an acronym coined by Dolby Laboratories, Inc. It describes their proprietary treatment of low frequencies. The LFE channel in licensed Dolby products is encoded 10 db's higher than the other channels. Here is their own description of LFE:

http://www.dolby.com/assets/pdf/tech_library/38_LFE.pdf

PCM is a unlicensed, non-proprietary uncompressed audio format. That means anyone and his brother can employ it. That also means that if a PCM track has a low frequency channel, which it may not, it probably will not be encoded 10 db's higher than the other channels. Therefore, the bass will sound "thin" compared to a DD source. Referring to a low frequency PCM channel as "LFE" is technically incorrect because the low frequencies are not handled in the same way as DD. Unfortunately, the term LFE is being bandied about nowadays so much it has lost it's original proprietary meaning.

Remember this... a PCM track does NOT necessarily have a low frequency channel, but it still can contain full low frequency response. Confused? Then do your own due-diligence and research the subject of bass management.

What I have learned from this thread:

PCM does not always contain a dedicated .1 channel for the subwoofer. If it does it will say on the Blu-ray disc "PCM 5.1". But it may not be at the proper level to be heard or felt at the same level as DD or DTS. And firmware updates may correct the problem in the receiver or the player. Is this correct?

And the lossless sound formats tend to be lower in volume (compared to DD and DTS) but have a more defined sound coming from all the speakers. Turning up the volume to the same level will make the lossless then sound better than the lossy ones.

And lastly, so since many Blu-ray movies come with PCM 5.1 sound, and many of the HD-DVD movies come with Truehd, does that mean HD-DVD's version of a movie may have a punchier sound than the Blu-ray version of the same movie because of the better bass management with Truehd?

Man this stuff is confusing! Give me simple DD and DTS!

What?

Posts near the top and middle of this page as well as your summary indicate that LPCM tracks are lower in volume and have problems with LFE?

I experience none of this and in fact my lossless/LPCM tracks are significantly higher in volume.

What am I missing here? Did I read incorrectly?

I have a Denon 4308ci connected by way of HDMI to a PS3. I even chose to select my front speakers as large, crossover@ 80hz and have LFE set to mains and sub and it is amazing.

Some people in this thread are really confusing others by arguing semantics.

LFE refers to the Low Frequency Effects track. Dolby invented the term, but it is now in standard use by everyone in HT. As far as I know, every Blu-ray movie release from a major studio includes a low-frequency effects (LFE) track.

As noted in this thread, the primary difference between "LFE" on Dolby Digital and LPCM is the encoding level. The "LFE" channel on LPCM tracks is encoded 10dB lower to avoid clipping. As a result, the low-frequency effects or "LFE" won't be nearly as pronounced on LPCM titles unless your player or receiver boosts the volume. Some players appear to do this automatically, like the Sony PS3.

Some receivers boost the "LFE" channel on LPCM tracks, or include the option to do so. I think Sony confused some A/V receiver vendors by applying this boost in the PS3 (the most popular Blu-ray player). Many players do not implement this boost -- they rely on the receiver to do so. This is clearly evident in A/B playback of a LPCM title from a Panasonic DMP-BD30 and Sony PS3 on my Denon receiver.

if we had a "gold star" emoticon, i'd give this post one... hopefully this post will make both camry and quad understand what is going on...

Ditto, my Halcro surround processor sees all LPCM tracks as recorded low (overall). THe bass is there but I have to turn up the gain 5 db to 10 db relative to DD / DTS lossy tracks.

I have a XA2 HD DVD and a Panny BD10.

I have an older Rotel RSX-965 receiver with 5.1 analog inputs. So if I buy a player that both decodes TrueHD and DTS-HD MA, and converts to analog, I shouldn't have to adjust the LFE channel. But with PCM I may have to increase the LFE (or level of the subwoofer) depending upon which player I buy, correct?

With decoders and DAC's both being equal, will my sound be as good as bitstreaming the still encoded TrueHD and DTS HD MA to a brand new receiver that does the decoding and converting instead of the player?

You're still going to have possible bass management issues by decoding in the player unless the player has adequate BM. The Panasonic DMP-BD10a appears to have basic BM. You will not have any BM available in the Rotel if you use the analog inputs.

I know many statements have been made about the Panasonic DMP-BD10a not having the ability to internally decode DTS-HD MA. However, it does have an internal DTS-HD decoder. The DTS website states:

"You can enjoy DTS-HD Master Audio and DTS-HD High Resolution Audio if you have a new Blu-ray Disc or HD-DVD player with a DTS-HD Audio decoder built into the player. The audio will be decoded inside the player and passed to the receiver in two different ways.

HDMI 1.1 or 1.2 Connection

In this scenario, the high definition player would output the audio as an uncompressed 6 to 8 channel linear PCM digital audio stream. You will need a player with a built-in DTS-HD Decoder, and both player and AV Receiver need to include HDMI version 1.1 or 1.2* outputs/inputs. HDMI stands for High Definition Multimedia Interface, and is a single-cable connection designed to accommodate digital multi channel audio and video. Simply connect the HDMI cable from the output of the player to the HDMI input of the AV Receiver. The DTS decoder inside the AV Receiver will "ignore" the Linear PCM stream and pass the audio stream on to your receiver's digital-to-analog converters and then on to the 5.1 or 7.1 amplifier. This way you can enjoy DTS-HD Master Audio that is a bit-for-bit identical to the studio master.

6 to 8 Channel Analog Connection

In this scenario, the high definition player will output DTS-HD Audio through the analog outputs of the player to your AV Receiver. The DTS-HD Master Audio or DTS-HD High Resolution will be decoded by the player and sent out as analog audio signals to the AV Receiver. You would Simply connect 6, 7, or 8 RCA cables from the analog outputs of the player to the analog inputs on your AV Receiver. The number of analog cables will be determined by the number of analog output/inputs on the player and receiver. The analog signals will go directly to the receiver's amplifier section. In this way you can enjoy DTS-HD Master Audio that is bit-for-bit identical to the studio master."

Go here...

http://www.dtsonline.com/dts-hd/dtsh...g-receiver.php

The Panasonic BD10 cannot decode DTS-HD Master Audio (the tracks FOX titles and some new New Line titles). It can only decode DTS and DTS-HD High Resolution.

Panasonic BD10 will only decode the standard DTS track on DTS-HD MA titles. The Sigma Designs processor in that player isn't fast enough to decode DTS-HD MA.

Come to think of it, I believe I have a 10db gain for LFE set on my Denon and I just leave it at that, but it seems consistently normal and discernable whether it be BD, DVD or PS3 games.

Here is a question then. What is the difference between turning up the volume on the sub itself as compared to the LFE gain by 10db's on the receiver?