HT vs Stereo - an issue not covered?

[purplepeople]

Ensen, thatnks for taking the time to post the history and an overview of the technicalities, your kindness is appreciated, but I already knew them, and they are really moot to the points I was trying to make.

... I have never found in my experience that really good 2ch was an impediment to the suspension of disbeleif when playing movies, unless you simply want the gee-whizz stuff, or watch noting but Die Hard type flix.

If HT is the priority, go for it, set it up multichannel, but you will lose out a lot in 2ch. Cost no object and custom theatre room installations are excluded from my comments.

The tips were as much for lurkers, the novices and the search engine as those who post on this thread.

(Bill: I do hope you now have too much food for thought, as I always believe more information is better for decision-making.)

I agree that good 2-channel goes most of the way to suspension of disbelief provided that the software is good. Good script, good acting, beautiful photography, etc. Some films will sound horrible no matter what and some films can withstand crappy audio reproduction. But that extra 2% matters to most of us or we wouldn't be chatting about it and trying to figure out ways to DIY. And I would venture that most of us can tell the diff.

If you've setup stereo properly, going to 5.1 is a question of adding more quality not just adding speakers. Get the 5.1 correct and you'll get the stereo right. If not, then the studios have no idea what they are doing and since we listen to their work all the time, I'd say that was hard to believe. I think you underestimate the capability of a good 5.1 set-up to play stereo on the two mains.

Engineers will often listen to stereo mixes on the same LR mains as the listen to 5.1. And yes, they usually try every pair of LR monitors just to check all reproduction possibilities. But they do use the 2.0/5.1 a lot. If they didn't trust the set-up they would make changes or work somewhere else. The specs do say to add channels to the exisiting stereo rather than re-craft the specs for 2-channel entirely.

There are certainly bargains in audio and it takes some searching to find them. And even then some people will never give those brands the time of day because they believe that $$ = Good Sound. I of course do not agree with that in the least.

... I run my center slightly overhung on the top of the TV the baffel hangs over the edge and the center's mids and tweeter are aimed at the listening position with a laser (same for the mains) because of this I get a seamless front pan from Left to Right and dialogue is on screen where it belongs.

Agreed. Once I've found my price point, I believe in test driving as many as possible and as hard as possible before purchase. That's how I came to studio monitors. At first, I found it hard to believe that you could get 2 good speakers and bi-amping for less than C$1500, never mind at C$750. Now maybe a pair of Aerius will whup my pants off, but I don't think so. Maybe pull them down to the crack. And for the same cash I'll just get some active Genelecs. Not the same visual wow factor, I'll grant.

Interesting method with the centre channel. Are you setup for wide audience or sweet spot? I'll guess sweet spot due to the laser. Setting up for sofa audience is a slightly different aiming method and forces a slight compromise that I think is Brett's complaint about 5.1 vs 2.0. I just don't mind getting up and toeing in the mains the morning after home movie night. If you are interested, there are some AES articles re: engineers preferring dipole surround speakers for playback of 5.1 but needing the accuracy of monopoles for mixing.

Boy would i ever like to see and hear an actual HD3D theatre.

They shouldn't be anyone's reference -- better can be achieved.

HD3D doesn't seem to have an audio spec, just visual. Could you elaborate about HD3D vs. THX.

Better can be achieved. But considering the size of the theatre, the size of the screen and the number of speakers, it's hard to believe they can even balance the system for most of the seats. Whatever you do, don't sit under the balcony that houses the projector. A lot of the surround information is missing under there.


ensen.

 

[planet10]

HD3D doesn't seem to have an audio spec, just visual. Could you elaborate about HD3D vs. THX.

The spec is mostly in my head & notes. We haven't done all the R&D yet so things are pretty liquid. Since it is a video source these theatres will have a larger screen to 1st row spearation and viewers will be in a much less sonically compromised spacing from the screen (ideally 3 to 4 screen heights to row 1). At least 3 channels of surround -- one being up. Line arrays up front (only 3dB per doubling SPL loss and much broader image capability) on either side of the screen. Each line arrary with prodigious bass capability. Active with digital XO (source will be digital, leaning toward DSD at this point)

At 1st at least we will also have control of the entire audio track from capture until presentation...

dave

 

[Brett D.]

LA's in a commercial theater? Sounds like my kind of theater!

 

[Brett]

I agree that good 2-channel goes most of the way to suspension of disbelief provided that the software is good. Good script, good acting, beautiful photography, etc. Some films will sound horrible no matter what and some films can withstand crappy audio reproduction. But that extra 2% matters to most of us or we wouldn't be chatting about it and trying to figure out ways to DIY. And I would venture that most of us can tell the diff.

If you've setup stereo properly, going to 5.1 is a question of adding more quality not just adding speakers. Get the 5.1 correct and you'll get the stereo right. If not, then the studios have no idea what they are doing and since we listen to their work all the time, I'd say that was hard to believe. I think you underestimate the capability of a good 5.1 set-up to play stereo on the two mains.

I hear what you're saying, but you're still missing my point. The centre (usually uneccessary in most domestic rooms), the rears only add a couple of percent total, as you said, and most films have so little rear info encoded into them that they're often hard to tell when they're turned off*. And to get that, given a fixed budget, you require 3 extra speakers and amplifiers and a processor. For the same money, I could get a much better set of main speakers and amps, for an overall improvement of way beyond the couple of percent extra you get from surround, and get better 2ch for music.

* I did this experiment a lot when I had the HT, often with the help of a friend with the remote so it was blind. My rears were a set of Tannoy HPD385 and the mains were Gold 15's, driven by either the onboard amps, or 4 channels of good tube. So high quality mains, and rears, with tight controlled and the same dispersion patterns between the front and the rear, something I've almost never seen anywhere else. The room was good acoustically, moderately large, no spousal unit-relayed placement issues and set up, both by ear and with reference to my spec-an and RTA.

I've also set-up a number of HT's, or more often, repaired faulty professional installs, so I do have some experience in the matter.

For 99% of people with a decent 2ch system, a 5.1 or more will bring little or no real benefit, even when they build it with the same quality gear in the rear.
Note; in earlier posts I've said cost no object and total custom room installs were a different issue.

I also went after that last 2%, but found that it wasn't worth the expenditure, or potential placement hassles (to really reap that last 2%) in real world rooms.

 

[purplepeople]

I hear what you're saying, but you're still missing my point. The centre (usually uneccessary in most domestic rooms), the rears only add a couple of percent total, as you said, and most films have so little rear info encoded into them that they're often hard to tell when they're turned off*. And to get that, given a fixed budget, you require 3 extra speakers and amplifiers and a processor. For the same money, I could get a much better set of main speakers and amps, for an overall improvement of way beyond the couple of percent extra you get from surround, and get better 2ch for music.

...

I also went after that last 2%, but found that it wasn't worth the expenditure, or potential placement hassles (to really reap that last 2%) in real world rooms.

I get you now. You go for the 2-ch because cash and room forces you to choose between better music or better movies... and music takes priority.

In my case, I can tell when I've forgotten to enable the surrounds since my DVD collection tends to have the effects (mostly sci-fi and war... go figure!). On most other systems I can tell when they're off because there is no hiss coming from the rear quarter. My DVD software requires 5.1 for best results.

Just as you imply for yourself, my problem is that my CD software also requires excellent 2-ch for best results. But, the next audible level up of 2-ch costs so much more that I can implement 5.1 very well for less than the difference. If I had to buy everything, no, but since I can DIY, then I'll go for it.

ensen

 

[Brett]

I get you now. You go for the 2-ch because cash and room forces you to choose between better music or better movies... and music takes priority.

Cool, I knew we were missing each other somewhere in the middle. For many people HT is a great pleasure, and the added channels etc worthwhile, esp if like you the flix have a lot of special effects etc (I'm also a big SF fan). I also watch a lot of European movies and dramas where there is little rear info, and I think the majority of movie watching people would also view movies with little rear/centre most of the time. So it's not automatic for me that most people will benefit from the extra channels, most of the time, and in many implementations (combined with 2ch) it's better to go with maximum 2ch. I was simply trying to point out to Bill, that all the extra hassle and expense may not bring the rewards a lot of HT fans say, because of different movie choices etc, and simply wanted to get some balance into the discussion.

Just as you imply for yourself, my problem is that my CD software also requires excellent 2-ch for best results. But, the next audible level up of 2-ch costs so much more that I can implement 5.1 very well for less than the difference. If I had to buy everything, no, but since I can DIY, then I'll go for it.

I also DIY, and the major thing that would stop me from implementing a centre and rears, now, is space. I have all the parts to hand and a large room (no WAF!), but horns are BIG and my mains already completely dominate the living room. The majority of my system use is analogue music (vinyl) but 30-40% would be movies as I can't get TV well here, and the old lady next door complains if I put music on at night though even big explosion filled movies don't seem to bother her as much. I think it's the lack of melody line in the movies, because my evening music selections are quite soft.

Cheers

 

[purplepeople]

The spec is mostly in my head & notes. We haven't done all the R&D yet so things are pretty liquid. Since it is a video source these theatres will have a larger screen to 1st row spearation and viewers will be in a much less sonically compromised spacing from the screen (ideally 3 to 4 screen heights to row 1). At least 3 channels of surround -- one being up. Line arrays up front (only 3dB per doubling SPL loss and much broader image capability) on either side of the screen. Each line arrary with prodigious bass capability. Active with digital XO (source will be digital, leaning toward DSD at this point)

At 1st at least we will also have control of the entire audio track from capture until presentation...

Based on the images, it seems that the room will have to be pretty large just to accomodate some of the "huge" 3D visuals. Anything small and the objects would appear to extend into the walls - note that even black walls would have some visibility would interact with the image as a kind of dimmer.

So, a large room would require that sound reaching the audience at the back not be delayed by the speed of sound. At greater than 35m long, the delay will be more than 0.1 sec. Assuming that the audience won't notice that delay of the mains, your surrounds at the back would have to be delayed by at least that amount compared to surrounds at the sides of the room near the front. I don't actually know how they do this in large installations - could you elaborate?

Also would you bring your audience away from the back wall so as to prevent the first reflections from that wall smearing the sound? I find this effect in even some of the THX rooms so I tend to choose seats that are about 50-70% of the room length away from the screen.

And your high surrounds - will they be directed down and will there be a grid?

As this is a venture, can you even talk about this?

I also DIY, and the major thing that would stop me from implementing a centre and rears, now, is space. I have all the parts to hand and a large room (no WAF!), but horns are BIG and my mains already completely dominate the living room. The majority of my system use is analogue music (vinyl) but 30-40% would be movies as I can't get TV well here, and the old lady next door complains if I put music on at night though even big explosion filled movies don't seem to bother her as much. I think it's the lack of melody line in the movies, because my evening music selections are quite soft.

How does that old adage go? "The better the audio, the less likely you'll notice how loud it is until you try to talk with the person standing next to you."

Maybe the explosions don't vibrate through the walls as much as we think. I'm not saying that the horns aren't pumping them out, but maybe because they are not actually connected to the room, unlike most subs that sit on the floor, the units don't create as much structural vibration.

ensen.

 

[JOE DIRT®]

quote>Also would you bring your audience away from the back wall so as to prevent the first reflections from that wall smearing the sound? I find this effect in even some of the THX rooms so I tend to choose seats that are about 50-70% of the room length away from the screen.

I have found 60% away from the screen to be a good starting point although it is not always viable in most rooms....thats when I play the gains on my rear channels to tone them down.


DIRT®

 

[purplepeople]

Hey everyone!

I just watched "The Right Stuff" - you know, the first of the really good astronaut movies. It was in the under C$20 pile so I had to have it. Heh!

It won 4 Oscars - Editing, Score, Sound and Sound FX Editing - but I remember it sounding better than it does in my copy.

Now, this DVD is supposed to be remastered in AC3, yet it seems that all the engineer did was decode the stereo matrix and re-record the tracks directly into 5.1 discrete channels. The flying sequences are fine, but all the dialogue seems to be down in levels almost as if they dropped the summed centre signal by more than the required 3dB. And the surround signals are louder than normal, as if they boosted it by more than 3dB. Bunch of amateurs! Oh... sorry everyone, we're mostly a bunch of amateurs and I know we're significantly better.

So there it is, even if you've got all your levels set just right and speaker placement is close to optimal and you've done all the other things just right.... if you've got bad software, you've got nothing.

Thanks goodness the film is so good that I could suspend my disbelief (in the sound) after temporarily re-setting the levels just for the viewing.

ensen.

PS: I hope they don't just put Chuck Yeager into orbit after he dies. He deserves more than Roddenberry. He should be soft-landed on the near side of the moon on a mountain renamed after him. And not just his ashes, but his entire body in a nitrogen-filled spacesuit to be preserved for all time. Without his work on the speed of sound, none of that other crap could have happened.