Laserdisc Dynamics vs Blu Ray

LuSh wrote: »

I have a couple of comparisons I'd love you to make. Some on DVD, some on Blu Ray.

Apocalypse Now LD (Dolby Surround PCM/ Red & White analog) vs. DVD Dolby Digital
Empire Strikes Back (AC-3 or Dolby Surround PCM/ Red & White analog) vs DVD Dolby Digital
Independence Day (DTS LD) vs Blu Ray DTS-HD
Die Hard (Dolby Surround PCM) vs Blu-Ray DTS-HD
Matrix (PCM) vs Blu Ray Dolby TrueHD
Braveheart (PCM/AC-3) vs Blu Ray Dolby TrueHD
Terminator 2 (PCM or AC-3) vs Dolby TrueHD
The Fifth Element (PCM or DTS) vs DTS-HD
Mission Impossible (PCM Surround) vs Blu Ray Dolby Digital 5.1
The Rock (PCM Surround LD) vs Blu Ray 5.1 PCM

Those are some ideas. I really think it would be a neat test. My understanding is that LD never compressed the dynamics found on Theatrical cuts, DVD and Blu Ray are watered down in terms of dynamics. This has nothing to do with resolution but rather the differences between the quietest passage and the 'big explosion'. I'm only working off of memory and it seems that there are many people who argue over this but few that have actually done the test. Many of those that collect LD will never buy Blu Ray (not really into the latest and greatest) and most of those that purchased Blu Ray were the first ones to ditch their LD for DVD. Let me know your findings I'm really interested to know.

Lush,

I have some of the discs to compare in your list.
The Matrix LD Vs. Blu Ray
Braveheart LS Vs. Blu Ray
Die hard LD Vs. Blu ray
T2 LD Vs. Blu Ray

It would also be interesting to compare The Song Remains The Same LD Vs. Blu Ray, being as it's audio focused. Unfortunatley, there are different (audio/video) edits and I already know the master tapes used for the later (2nd) release of the LD, DVD and Blu Ray were deteriorated compared to the original LD, but it would still be interesting to compare the fidelity of them from a compression point of view. I'll hook up the LD-S2 probably this coming tuesday and compare. Maybe sooner.

Greg

Could the studios put Theatrical Audio Cuts on bluray discs if they wanted too? And what would it sound like on a medium range HT system consisting of a decent reciever, amp, 5.1 speaker system?

LuSh wrote: »

Bluefox,

Yes LD is a very old technology that predates CD;' however it was marketed as the ultimate collectors format and was way ahead of its time. Vinyl is a very old technology as well.

Mon40CSMM10,

The Audio Retriever if I'm not mistake is an algorithm used to restore missing information or resolution. What I'm talking about is dynamics and not resolution. Not only did LD use PCM soundtracks (2-Channel re-encoded into multi) it also used (to my understand, I could be wrong) Theatrical mixes which were mixed specifically for film and movie houses. DVD/BD's are now usually remixed for home use. The idea is that most home playback devices are not up to snuff (Flat panel speakers, HTIB's) and the mix is tailored to these types of playback systems.

DigitalVideo,

I'm sure they could, however I don't believe they will. Again, I could be wrong. I started looking into this well over a year ago. I own a Blu Ray player but part of me always wondered. I watched a video on youtube that also perked my interest. I remember watching Apocalypse Now on Laserdisc and waiting for the DVD release. I finally bought the DVD and man what a let down. I understand Blu Ray should be better but I wonder about the differences in Dynamics.

I'm starting to understand a little bit more now. But isn't the purpose of LPCM on bluray to put on the disc the original sound that the directed intended without any "interuptions" from Dolby/DTS?

If Theatrical Audio Cuts were put onto LD with no problems and worked on people's mid range HT setups why isn't it today on bluray? I think it's safe to say that many HT's in today's homes are superior to many of the HT's in people's homes 20 years ago. So why couldn't the recievers, amps, 5.1/7.1 setups deal with it?

I saw several Deutsche Grammophon LaserDiscs at Salvation Army a few weeks ago. They were classical music of course and i assume they included the video track of the concertos. They were asking $5 apiece for them, but as i don't have a LaserDisc Player and i can't tell Brahms from Bach.... I just left them there for someone who could appreciate them

LuSh wrote: »

My experience (from memory is the same). I'd love to have users try it and report back. Hopefully headrott can let us know his results.

I'd like to try that and see if I can find a Pioneer LD player to put in place of my Oppo bd player and do a back to back comparison, maybe a blind test and have some family members try to tell the difference. I still doubt a LD would beat a bluray LPCM like Disney's Pirates Of The Caribbean which Disney released on LPCM.

LuSh wrote: »

Digital,

it wasn't a pissing match...simply put people had better home theater back in the day on average. Sure people like you have great HT's but many people consider home theater a system they can buy at wall mart. You couldn't buy HT in Walmart 20yrs ago. No different then most people had better stereo systems back 20-30yrs ago. I've been too two different partys this year. One couple had a Bose wave as their main stereo, another had a digital cable box playing music thru their plasma screen. That was their stereo system.

I wasn't trying to bait you or turn this into a back and forth contest. I was curious as to the sound between LD and BD is all and how my HT would sound with LD.

How big are these things.....laser disks were a bit before my time.

OK, maybe I can try that. I am just so buisy it's hard to even get time to listen to my BAT VK-3i pre-amp I just got. I will see if I can compare the 2 channel PCM and True HD/DTS HD. I'll get back to you as soon as I can.

Greg

LuSh wrote: »

I understand the DVD vs Laserdisc comparison because of the resolution and lack of compression found on Laserdisc in Dolby PCM and even DTS. What I've found interesting is that Laserdisc used Theatrical Audio Cuts while DVD and Blu Ray use watered down Studio mixes for the home. The theory being that many users will use cheaper speakers and television's as their primary audio sources. A Theatrical Audio cut offers better dynamics most cheaper systems couldn't endure, therefore the mix down.

That's incorrect, actually. The "studio mixes" you're referring to for the home are typically just re-equalized for near-field listening, which means a slight rolloff of highs similar to THX's default rolloff... and nothing more. The only other differences in the audio itself would be those inherent to lossy perceptual encoding (which is typically summation of audio that we don't necessarily perceive, which is what DD and DTS are both based on). Regardless, the dynamic range of the mix (or the mix itself) isn't altered when remixing a track for home use (barring a few exceptions where new mixes were done for DTS-specific releases on DVD - See Saving Private Ryan DTS edition for a perfect example.). It's essentially the equivalent of the RE-EQ feature on THX receivers, but done before the encode, which is why you typically see those "home mixes" on THX-branded DVDs. The problem with that where DVD is concerned is that people using their AVR's THX RE-EQ (or the Audyssey target curve on Audyssey-enabled AVRs) are essentially filtering the highs twice, because they were already filtered before the encode on those particular DVDs. That said, the vast majority of DVD soundtracks are NOT pre-compensated for near-field listening, and the ones that have been are typically labeled as such (i.e. "home theater mix" or "THX certified"). So if you had a laserdisc with an AC-3 track and a DVD, both encoded from the same master, laserdisc would have no advantage. If the DVD was compensated for home listening, the laserdisc would sound slightly brighter... but since the rolloff audibly starts to take effect near 12-14kHz, it's not going to be a massive difference, and given the different acoustic needs of large and small spaces, the DVD could very well sound superior.

To my knowledge, soundtracks on Blu-ray discs don't pre-compensate for near-field listening the way DVDs often did, so the theatrical mix is encoded directly. There's no need for DRC before the encode because both DTS and Dolby's variants of lossless encoding make allowances for DRC at the decoding level, using metadata in the bitstream to define the amount of compression. So long as you have DRC disabled in your AVR, you should be getting an identical recreation of the original theatrical mix, both in frequency reproduction and dynamics. That's the whole point of having the lossless codecs.

That's not to say that people who are going to be using TV speakers aren't accounted for where Blu-ray is concerned, since the base Dolby and DTS core tracks essentially have the same range as DVD tracks (though they're encoded at a higher, but still lossy, bitrate). Dolby and DTS handle this in different ways. Dolby has a base track (typically a 640k DD track) inside the bitstream for the TrueHD track, with the TrueHD data held separate from the base track. So if your system can only take the base DD track, that's what it sends out... If your system can play the TrueHD track, it sends that. DTS Master Audio encodes the DTS core/HD track, then has additional metadata above and beyond that which contains the additional data needed to restore the audio to master quality, which occurs when the core/HD track is summed with the additional metadata (which is partially why DTS-MA takes more processing power to decode than Dolby TrueHD). Two different ways of handling things, both of which losslessly recreate the original master.

As far as Laserdisc vs. DVD on a strict format level, AC-3 encoding is AC-3 encoding, and the differences will come down to bitrate. Demodulated AC-3 surround tracks on laserdisc were limited to 384k, whereas DVD tracks are encoded at 384k at minimum. DTS tracks on laserdisc, however, were full bitrate (1.5m/s) whereas DTS tracks on DVD are typically half bitrate (768k), with a few rare exceptions. And stereo PCM tracks on laserdisc were 16-bit/44k, which is CD-quality audio. Hardly comparable to what TrueHD or DTS-MA are capable of, especially over 20kHz.