Audio for Laserdisc Player (1 Viewer)

[Robb Cadigan]

Hi. I'm new to this and thought I'd ask for help. We are putting a media room in our basement. Primary use will be watching DVDs with a front projector (Marantz or Runco DLP).

I also have an old Pioneer DVL-700 combo laserdisc player that I would like to make use of for some of my LDs that aren't out on DVD yet. I would use a new DVD player for the DVDs and use this old unit exclusively for LDs.

Anyway, I was told today that the new AV receivers do not process the AC-3 sound from LDs anymore, so I would probably have to buy a separate processor for this. Otherwise, I wouldn't get any sound.

Does this make sense? I only have a handful of LDs I want to watch, so I don't want to spend a lot just to watch these. I can't believe I can't just plug this unit into today's AV receivers and get sound (maybe not the best surround, not functional at least).

Any help would be very much appreciated! Thanks.

 

[greg_t]

In order to get Dolby Digital, or AC3 as it's called in the laserdisc world, you will need a LD with an AC3 RF output, and an RF demodulator. You run a cable from the RF out on the LD player into the RF demodulator, from there you can run a digital cable directly into your DD reciever to get DD sound. I don't know right off hand if your DVL 700 has an AC-3 out or not. I got my RF demodulator off ebay for $125 new. These are getting more rare and more expensive.

You can get DTS sound on DTS laserdiscs by simply running a digital connection into a digital input on your DTS reciever. YOu can also connect the LD player to the reciever via regular RCA cables and get prologic sound. Hope this helps.

 

[Tony Kwong]

DVL-700 does indeed have a AC-3RF output.

 

[Michael Reuben]

Otherwise, I wouldn't get any sound.

This part is not true. You can get very fine 2-channel sound (either digitally, if the player has a digital output, or through the analog outs), which any good recent-vintage receiver should be able to process into a good surround field using DPL2.
LDs have four separate tracks: 2 analog and 2 digital. For various reasons of compatibility, the AC-3/DD signal was always encoded on one of the analog channels. That left the 2 digital channels free for a high-quality 2-channel matrixed surround mix.
M.

 

[Chris Brown]

The 2 channel Dolby Surround encoded PCM tracks on laserdisc are almost always VERY good. The PCM tracks are very detailed and make Pro-Logic come alive like no Dolby Digital 2.0 mix ever could. Most people are so impressed by the PCM tracks that AC-3 becomes a moot point.

 

[Tom Blizzard]

Quick question, Chris
I've noticed that several LD owners express this same opinion about the PCM track. You probably know Rachael,from Knoxville, she seems to pick the PCM track over DD 5.1 in may cases. Does this mean that the PCM on a LD is better than say the PCM tracks on a standard audio CD?? Just woundered why you feel it is better?? Can it be explained as far as the encoding process or maybe bitrate??
Thanks, Tom B.

 

[Chris Brown]

Well I don’t think it’s necessarily better than PCM on CD, in fact I think it’s the exact same. The difference is that most PCM on CD is encoded to be played back in simple 2.0 while PCM on laserdisc is generally encoded in Dolby Surround for decoding by a Pro-Logic decoder. The way pro-logic works on a basic level, is to encode the surround information slightly “out of phase” which the pro-logic decoder then recognizes as sound information that is supposed to be routed through the surround speakers. Knowing this, you can imagine that the quality of the surround sound reproduced by Pro-Logic will depend heavily on just how accurate this “out of phase” information is. This is where PCM really shines. The accuracy of PCM allows VERY good and precise Dolby Surround information to be encoded onto the track and when decoded you not only have the advantage of accurate surround information, but a high level of clarity overall.

 

[Rachael B]

I do like PCM. Most pre-1990 stuff that was originally recorded to be Dolby Stereo sounds better in stereo or Pro-Logic on LD. STAR WARS AC-3 from the Special-Ed edition is a good example. About the only time the AC-3 gets very cute is when Luke is in the canyon where he gets mugged. He yells something and the AC-3 has a nice echo of him. Otherwise, the PCM is better. The AC-3 is lossy and lacking in detail in places, out of bits...? The PCM has more punch. Seperation isn't all that important on this film despite some re-recording. The PCM on THE GODFATHER AC-3 LD is better than the DD IMO.
The PCM on STAR WARZ PM rivals the AC-3 track. For me the AC-3 EX track wins out. The pod race is so well done, not to mention a few other things! COURAGE UNDER FIRE is awfully nice on AC-3 LD. The DTS DVD might be as good. The PCM is real good but the directional cues on the helicopter parts are extra good on the AC-3. You really only need two speakers to get great sound from LD's. Imagine trying that with a DVD player.
There are way too many awful sounding 2.0 tracks on DVD's. How about THE ABOMIDABLE DR. PHIBES' DVD 2.0 track. It's a typical MGM hatchet job! My sub does nothing on this DVD, nothing! The disc makes your speakers sound like they're covered by sail canvas, or maybe multiple layers of sail canvas. :frowning: This is a very musical movie and the DVD spoils that. The PCM on the 2.0 LD is a sub tester. When Phibes plays his organ, watch out.
2.0 PCM is great for all mono too. The 30's and 40's films do very well on LD. PCM is in the original DVD spec's. In '97 & '98 I got three DVD's with PCM. Two were computer animations set to music and the one film was AMAZON WOMEN ON THE MOON with terrible 1.0 PCM. It's 1.0 track suffers from sail canvas syndrome too. It sucks! The LD sounds way better. The 2 animations sound very well, CD-quality seemingly...?
If DVD's were encoded with uncompressed 2.0 PCM, Dolby Pro-Logic 2 might be the preferred mode of playback? Maybe? DVD sides would be shorter though. I'm not exactly sure how much shorter, but there would be alot of flippers and two-disc sets.
You're giving up something with compressed audio. Directionality isn't all that important with most films. It's a big deal in action films today as they've evolved in the past decade. The directionality and cues in 5.1 formats have become an artform, I suppose, but it's rather unimportant in many films. 5.1 formats frequently throw away, or average out, or somehow lose little sonic details sometimes. This is verifiable when you compare DTS, AC-3, and PCM on LD's.
I did LD's for 10 years before I got DVD in '97. The first thing I noticed was the pic was better but the sound was generally worse. I was infatuated with 5.1 sound when it was new. Now, I'm more objective and I quess it doesn't hurt that I have better PCM equipment than I used to have too.
If LD had done better back in the 80's, PCM proably would of been on LD before CD. Sony was aligned with Pioneer on LD but decided to share it's PCM tech with Phillips to create CD. They didn't see a big enough or fast enough pay-off with LD, so they went looking for another avenue of profit. Best wishes from Laserland!