big screen - two channel system enough for dialog?


If I have a large screen (100"+), will I need a dedicated center channel to hear dialog well??

My priority is music, and movies are mostly drama and comedies where dialog is critical. Surround effects are NOT a priority. Many folks here believe you can get much better value from 2 channel systems, but I am getting older and dialog intelligibility is key.

I am concerned about blu-rays needing to downmix from 5 to 2 channels and with such a big screen and separation of my mains, will two channels just make the dialog more diffuse??
tswei99
I am just speculating but with that kind of separation and the nature of cinema dialog, a center channel will serve you well, as might a subwoofer.
I am a dedicated 2 channel person for music and don't own a home theater system, but in your case for movie dialog I would buy an absolutely and fairly substantial center channel. It should easily be the equivalent of your front mains, which I am guessing are going to be very high caliber gear.
I've done this type of thing before. Personally, I find surround sound annoying. If stereo is your main concern, don't compromise your 2 channel system at all. The first thing you need to do is hook up your video source up to your main system and just see how it sounds. You can probably stop there without changing a thing. If not, you may have to get some separate HT components. At that point, it becomes hard to make a recommendation because there are so many different paths you can take to get the results you are looking for. For example, you may go with a receiver and some passive speakers, or a HT preamp and some powered speakers, or some type of combination. Its possible to use your current equipment and get a HT preamp with a pass through option, or don't touch it at all and just work around it. In the end, whatever you do will have to be based on decisions that you make. For me, as long as I can hear it, its good enough for me. I don't need much more than a TV with built in speakers. Most likely, what ever you choose will be somewhere between my basic needs of TV quality audio and your current 2 channel system.

Here's a couple of things you may want to consider. If you end up going with a centre channel, you may not want to buy one. The reason for this is that I find typical centre channel speakers are almost always over powered by the main speakers. You can always buy your way out of the problem by getting more expensive/powerful/bigger etc.. centre channel gear or just get a regular pair of stereo speakers. Put 1 speaker on each side of the screen and get a stereo amp (Or 2 powered speakers). Feed the same centre channel signal to both channels. Doing it that way makes it so much easier on the equipment. Just think how much more you would have to ask of just 1 centre channel to get similar results. Another benefit is the imaging. Its just like listening to a mono recording. You get a rock solid, stable image, that's very clear. The only other thing I would suggest is not to bother with side or rear channels. Its just not necessary. The system should sound fine with out them.If you like surround, thatÂ’s another matter. No reason to buy something like that unless you really want it.
I agree with Mechans.
I too vote for a center channel for great dialog. I also have a large screen which I use with a Sony front projector. I tried just two channel, but as mentioned found the dialog off. So I added a center, same speaker as two channel. Did wonders. All speakers are driven by the same type of tube amps, mono block types. Getting the balance right will take some time and work. If the source has a center channel track it will still take some time, even if you use the balance computer software. Sometimes a blend of the right and left channels works just as well.
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I have a center channel in my system and I have a 240" screen. I've watched movies in stereo with only the front mains engaged and the dialog sounded just fine, and while watching the movie, having no center channel did not call attention to itself and I thoroughly enjoyed the movies.

Before I went whole hog and installed a surround system, I watched movies on a big screen in stereo for years and never had a problem with the dialog being unintelligible.
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A center channel is not necessary IMO. If your speakers image well and you sit in the sweet spot they will work just fine. If you don't sit in the sweet spot the voices will not come from the right spot though.
It should reinforce center (improve imaging) for off center sitting position.
Mitch, how many seats do you have in your movie theater?
What's currently shown in there?
Stereo is great if you are sitting in the sweet spot. if sitting off to the side all dialog will obviously sound unnatural.
mitch, could I ask why you installed the surround system if stereo was OK for dialog?
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Marakanetz, I can comfortably seat eight people in one row facing the screen on couches. In a pinch I can seat another four along the side walls(two on each side). I show everything from blockbusters to romances and children's movies. I also watch all sporting events on the system. 90% of the time I watch movies alone. 90% of all television I watch is on the system. My 15 year-old son uses the system for video games on his X-Box and PlayStation with friends. He likes Halo, Call Of Duty and Assassin's Creed. I play old school Defender. I have to replace a projector bulb every couple of years for about $250.

Tswei99, before I installed the system, jets only flew from left to right. Now they fly overhead from front to back as they should. I installed the surround system because I wanted total immersion. I have a huge room and I wanted to take full advantage of it, I installed the biggest screen that would fit. Surprisingly stereo gives excellent immersion without a center channel if you include rear speakers. No doubt about it, a surround system beats stereo, but stereo is very good too....it is no slouch.

But as a some above has said, you do have to sit in the sweet spot for the dialog to be dead center if you're listening in stereo. But, even if you are not sitting dead center, the dialog is intelligible and good, just not centered.
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>If I have a large screen (100"+), will I need a dedicated center channel to hear dialog well??

No.

It may even be more intelligible without a center channel where you don't have an acoustically transparent screen which forces center channel placement above or below the screen where it gets a lower midrange boost due to the boundary proximity.

I turned off my mis-matched center channel in my main system and haven't gotten arround to building appropriate center channels for either main or bedroom systems (where it's on higher on my agenda since I sit off-center in bed which produces image shift, although that does not interfere with intelligibility).

>I am concerned about blu-rays needing to downmix from 5 to 2 channels and with such a big screen and separation of my mains, will two channels just make the dialog more diffuse??

Not with good speakers and setup.
FWIW, I'm speaking from experience here. I ran my 100" diagonal setup with mains 4' off the front-wall, 8' between tweeter dome apexes, center channel off. It's not an issue.
thanks for all the responses so far. i pose the question now because I am building this room from the ground up and am trying to figure out how much wire/conduit to lay, the general layout, and of course budget. from what i have read, there are lots of people who think 2 channel is not only better value, but superior in many ways.

i just worry about the separation of my mains when it comes to dialog as I will be using a pretty large screen and I don't want it to be high up. So that leaves mains spread apart which means they'll have to be well out into the room.

one solution i was thinking of was to use Klipschorns (i am one of those high efficiency plus low power tube kinda guys) in the corners. this would allow my big screen in the middle, at almost any height, maybe with a couple of subs underneath, and the horns off into the corner. This would leave the floor clear, a big bonus since I have small kids.

Zd542, I totally take your comment about centers being too small in many cases. the HT systems I have heard often have this problem, and I think quality two channel might even be better in this case as imaging might be better.

I know I can go with the trial and error method, just want to avoid tearing up walls, repainting, etc if I can.
20' diagonal screen seemed to me the size in Lowes theatres for sub-100 people audience:-)
If you are okay with the bass limitations of the K-horns, then a natural choice for the center channel is a single Cornwall or maybe a pair of Heresys.
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Marakanetz, I could seat at least two additional rows of eight people in my theater, but the people in the second and third rows would not be able to see over the heads of the people in the front row. The second and third rows would not be elevated. Therefore, I keep it to eight people in one row so everyone has a great seat. For kids movies I've had as many as 25 kids over for a movie...most of them sat on the floor and they loved it.

My theater is not a dedicated theater, it is also my living room and my music listening room.
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I've gone through 3 or 4 center speakers, and was never satisfied with any of them, due to their inability to render the human voice as well as my L/R tower speakers. I did not find any improvement in dialog intelligibility when using a center speaker. The biggest drawback with all of the speakers I tried was that they could not reproduce the baritone quality of male voices, no matter what crossover settings I tried. I finally have just decided to use the phantom setting with my L/R mains.
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I've gone through 3 or 4 center speakers, and was never satisfied with any of them, due to their inability to render the human voice as well as my L/R tower speakers. I did not find any improvement in dialog intelligibility when using a center speaker. The biggest drawback with all of the speakers I tried was that they could not reproduce the baritone quality of male voices, no matter what crossover settings I tried.

Agreed. That's why I use a full-range tower laying horizontally as my center channel. Anything smaller was inadequate and a waste of time.
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Hey Mitch, can you post picks? I'm curious!
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Marakanetz, the link below should give you an idea of the
room and the layout. When the room is my everyday living
room, the couches are along the walls. When I get ready to
watch movies, I move the couches so that they face the
screen. I sit 30 feet from the screen. You can see the
center channel on the floor at the bottom of the screen, I
place it on a platform that raises it two feet off the floor
at movie time. The room is 22 ft wide, 70 ft long and 22
feet high

http://forum.audiogon.com/cgi-bin/fr.pl?vhome&1178590685
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Nice digs.
I'm in the camp of use the center, and surrounds for home theater. Way back in the day, I started with just to channel for movies, and TV. I can't say I didn't enjoy it, I did. Very much back then. Mitches comment about planes flying past is exactly right. There are so many things going on in movies that only having two speakers will limit the experience.

I built a new from the ground up about 6 years ago. (119" screen, and Sony PJ) Regardles of what you do speaker wise, here are a couple things I would suggest.

I assume you will be using a PJ. I ran 3" PVC, 2" would work, from behind my equipment rack, (it's buried in the wall of course) up to where my PJ is mounted. When you make corners, don't use 90 degree elbows. It's better to use 2 45 degree elbows. It makes pulling wire through alot easier. Always pull an extra wire through so if you want to change, or add, you have an easy way to do it. If you use it to pull something new in, pull another extra one through. (since you will be pulling your spare out with the new one)

Even if you go the two channel route, run speaker wires to the back of your room. Just put a blank cover plate on the openings, and forget it's there. The last thing you want is to decide you would like to try the surround later and not have the wires in place. Speaker wire is cheap enough, don't limit your options. I've done some retro installs, and it's a real pain running wires through the attic, or basement, and trying to end up in the walls later. Try to cover any possible future changes now.
There is NO question that a proper center channel speaker will enhance dialog intelligibility. Keep in mind that the center channel is THE primary channel used by the audio guys when mixing for movies. Additionally, it "anchors" the sound to the center for those viewers who are off-axis and not in the sweet-spot.

So, don't cheap-out on the center channel. *Most* mfgrs. nowadays make a center channel that is complementary to their main channel offerings.

I currently run Gallo Reference 3.1s for my main L/R, Gallo Ref. AV Center for my Center, and Gallo Ref. AV for my surrounds. My sound is *superb*, and the 60 inch Mitsu DLP HDTV suits my needs for the moment. But I dream of a 92" Mitsu DLP sometime in my future...

-RW-
No offense, dude, but that room looks like a standing wave nightmare. I would *seriously consider placing some sound damping materials on the side walls near the 1st reflection points. Additionally, some thick, sound damping carpets would go a long ways towards killing the floor to ceiling reflection points.

But, other than that, it is one *hell* of a nice room for a home theater, ya oughta be charging admission. And hey, I need a gig right now, gimme one of those ticket-taker monkey suits with the pillbox hat and I'm yer boy!!

-RW-
I am sorry I did not read all of your posts thoroughly. Since you have the luxury of building the room, by all means take advanatge of the abilitiy to make the side walls and ceiling non-parallel. This will effedctively kill any standing waves in the room and largely eliminate nulls and voids in the rooms frequency response. If you have the money for it ($2k-$5k), I would *highly recoommend you employ the services of a firm such as Rives Audio. They are *experts* in such things and will give you invaluable information on the proper design and construction of a terrififc looking and sounding HT room.

Man, I wish I was in your shoes, you are one lucky man!!!

-RW-
10m ceiling is hard to manage for music indeed.
Rlwainwright,

did you mean Mitch4t's 22 ft wide, 70 ft long and 22 feet high room?

What makes this a standing wave problem, the relative proportions or absolute size??

My room is about 17' x 30' x 10'. It's also irregular (about 15' along the long wall the wall jogs in maybe 4' and widens). Will this be a problem??

I have yet to sheetrock it so I can make tweaks if necessary.
Rlwainwright,

did you mean Mitch4t's 22 ft wide, 70 ft long and 22 feet high room?

What makes this a standing wave problem, the relative proportions or absolute size??

My room is about 17' x 30' x 10'. It's also irregular (about 15' along the long wall the wall jogs out maybe 4' and widens to about 21'). Will this be a problem??

I have yet to sheetrock it so I can make tweaks if necessary.
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Rainwright, in theory it may be a standing wave nightmare, but in reality, the room sounds incredible from top to bottom. I have no such problems with my room. I am currently running a 7.1 system.

I am considering adding height and wide channels. Additional rear speakers in the ceiling are also under consideration.
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