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5.1 vs 7.1 for This Room

post #1 of 11
Thread Starter 
Hello everyone. I plan on using a 65" plasma. Please let me know which setup you would go with and why. The 5.1 is nice because I could, at some point, drop a projector screen in front of the plasma. However, I'm bound by sitting distance limitations from getting the full benefit of a projector screen. I think the 7.1 would work well. Is it overkill for my small room? The room acoustics are far from perfect. There is a fireplace with high mantle on the north wall. There's a vaulted gabled ceiling and walls on roughly only two sides. What do you guys think? I attached the sketches.

5.1


7.1
post #2 of 11
Thread Starter 
Or Option C - 5.2

I think this is the best I can do.

post #3 of 11
I think either layout A or C would work better than layout B, with a few suggestions: place the surrounds further apart (right surround in back right corner of the room, left surround where the wall starts on the back left), toe in the front speakers (a la layout A) so that they're pointed at the person on the opposite end of the couch, add some absorbtion to the right side wall to sound more consistent with the open left side.
post #4 of 11
Thread Starter 
Thanks Sanjay,

I redrew this with the fronts at 30 degrees (I see I still didn't toe them in properly, but you get the idea. The surrounds are at 110 degrees. I can use this orientation if I mount them at 7' from the floor. The tv shown is 65 inches with a sitting distance from the sweet spot of 6.5'. Actual distance when sitting back is probably more like 7'. I'm thinking I only need one good sub. I could put it below the tv or off to the left side. I am intending to mount the tv centered on eye level. With that said, should I put the center above or below the tv? I'd like to keep it as far away from the fireplace and the windows flanking it as I can. I can cover those windows with drapes and put my computer and receiver furniture on the top side of the room. That should help to block some noise. The rest of the wall above the fireplace has a massive oil painting... That's the best I got, lol.

What do you think of this arrangement?

Thanks for the help

post #5 of 11
Quote:
Originally Posted by Delacroix333 View Post

What do you think of this arrangement?
I think it looks better. If you're still open to suggestions, I have a couple more (with explanations).
Quote:
Originally Posted by Delacroix333 View Post

I redrew this with the fronts at 30 degrees (I see I still didn't toe them in properly, but you get the idea. The surrounds are at 110 degrees. I can use this orientation if I mount them at 7' from the floor.
That's fine for the mounting height of the surround speakers. I would mount them on the back wall, spread as wide apart as symmetrically possible.

I would also spread the front speakers further apart, with the left speaker at the edge of the front wall. The wider spread means that sounds on the left side of the soundstage will be to the left of the person on the left side of the couch rather than directly in front of them. Maintains left vs right directionality better for listeners outside the sweet spot.

The exaggerated toe-in (pointing each front speaker to the person on the opposite side of the couch), will keep the nearby speaker from dominating the soundstage and keep the far speaker from becoming relatively inaudible. The left speaker would normally be louder to the person on the left side of the couch, but by rotating it away, you attenuate the volume and compensate for the proximity. The right speaker would normally be much quieter to that same person on the left side of the couch, but by pointing it at that listener, you make it louder and compensate for the distance. It's an old trick, sometimes referred to as time-intensity trading.
Quote:
Originally Posted by Delacroix333 View Post

The tv shown is 65 inches with a sitting distance from the sweet spot of 6.5'. Actual distance when sitting back is probably more like 7'. I am intending to mount the tv centered on eye level. With that said, should I put the center above or below the tv?
Can you move the seating further back, like in layouts A & C. This will still give you an over-30° viewing angle (as long as you stay within 8.5' viewing distance). As for TV height and centre speaker placement, I would strike a compromise between them.

Ideally, all three of your front speakers should be at ear height (36-40 inches). Of course you can't do that with your centre speaker if your TV is at that exact location. Our human vision tends to bias downward about 12° or so. If I stood you up in a flat landscape and asked you to look straight out, your natural tendency would be to see a bit more ground than sky.

Most 65" TVs are roughly 3' tall. Rather than mounting it centered at eye height, if you could move it down about 6-8" it would fit nicely with your natural field of view AND line up better with the faces on screen (which are usually composed in the top half to third of the image). Best part, it would allow you to place the centre speaker above the TV and be pretty close to ear height. Works well for picture and sound.
Quote:
Originally Posted by Delacroix333 View Post

That's the best I got, lol.
It will work out fine and sound great. If your willing, I'll ask you for one more diagram. Start by placing the left surround speaker on the back wall, just after the gap (flush with the edge of the gap). The right surround speaker also goes on the back wall, where it meets the right wall (corner). Split the distance between them and make this the centre line of your set-up. Place the left front speaker at the edge of the front wall, just before the gap, and place the right front speaker the same distance from the centre line. Place the couch closer to the distance from the front wall you had it in diagrams A & C (or as close to that as you are willing). Finally, cross-toe the surround speakers like I suggested for the front speakers.

BTW, what receiver are you using?
post #6 of 11
Thread Starter 
Thanks for the awesome info Sanjay! I'll get another diagram drawn up this evening.

As for the receiver, speakers, and tv, that's another can of worms. I'm starting from scratch on this build so I'll need help there as well.

For the tv, I am interested in the Panasonic vt50 65" plasma.

For the receiver and speakers I'm looking for a good 5.1 or 5.2 for about $4000. I watch movies (40%), play pc games (40%), and listen to music (20%). With that said, I would probably listen to music more if I had an awesome setup.

Thanks again for the help. I'll post that revised diagram this evening.
post #7 of 11
Quote:
Originally Posted by Delacroix333 View Post

For the tv, I am interested in the Panasonic vt50 65" plasma.
That's the best that Panasonic makes. You might want to compare it to a similarly sized (64") Samsung plasma to find out whether you see much difference. If you don't then you could save some money by going with the Samsung. If you want to compare them, there is a whole section of the forum dedicated to plasma flat panel displays, where you can start a thread and ask questions.
Quote:
Originally Posted by Delacroix333 View Post

For the receiver and speakers I'm looking for a good 5.1 or 5.2 for about $4000.
There's probably no other aspect of audio that is more dependent on personal preference than speakers. I usually audition speakers using a few recordings that I'm very familiar with. As with the plasma TV, there is a section of this forum dedicated to speakers, where you can start a thread to get recommendations within your budget. The only suggestion I would make is to get 2 subs. There is plenty of research demonstrating that multiple subwoofers help smoothen out the frequency response (fewer peaks and dips) AND improve consistency from seat to seat.

As for receiver, I would get something with good room correction, like the Denon AVR-4311 or Onkyo TX-NR818; the latter can be had at significant discounts, which would make it my first choice of the two, leaving more of your budget for speakers and subs. Like most modern receivers, they come with a microphone, which you move from seat to seat in order to do automatic calibration (set the speaker levels and distances) and automatic room correction (equalize away the room's unwanted contributions to the overall sound).
post #8 of 11
Thread Starter 
Thanks again for the info Sanjay. I've updated the drawing. I had to change the location of the south wall a little due to a mistake during measurement. The surrounds have been placed at 110 degrees and then toed in to the center on either side of the sweet spot. The fronts have been placed at 30 degrees and also toed in to center on either side of the sweet spot. I used the dark lines to places the speakers. The dotted line represents the angle used to toe in the speaker. I like your idea for the center channel above the TV and will definitely use that. How would you place the two subs? I didn't want to get them near the fireplace and windows. If the subs are preferred wider then I could move them out a bit. I also put the size of a coffee table in there to see how that would fit.

I put the tv on a stand so I could move it closer to the viewer. Do you think 8'9" is too far away? I could move the tv up a little further if needed. I also think the couch really needs to move up about 9" to give more walk space by the door. That would take the distance down to 8'. If I move the couch up 9" closer to the tv, should I leave my surround speakers where they are? Even if I move the couch up the angle wont exceed 120 degrees from the sweet spot.

I'll start hunting for receivers and speakers as well. Thanks for the leads.

Please let me know if you see additional improvements to be made on the attached drawing. I'd happily draw it a few more times to avoid making mistakes during install. Have a great Thanksgiving.

post #9 of 11
Looks awesome! Nice and symmetrical. Taking into account multiple listeners on the couch.

Moving the couch a bit forward would be a good idea, more for traffic flow than anything else (won't hurt the sound). At 8 feet your 65" display will still give you a good 33° viewing angle. Also, don't feel locked into the viewing distance. Once everything is installed, if you feel like moving the couch forward a bit, then don't hesitate to do so. The reason I keep using words like "about" or "roughly" or "around" is because there is nothing hypercritical about these placements. You won't have to sit in the sweet spot with your head in a vise to enjoy this system. Everyone on the couch will have an enjoyable experience. If you do settle on a different location for the couch a few months after install, things will still sound fine (just remember to re-run auto-calibration).

If you end up using bookshelf speakers mounted on the wall rather than tower speakers standing on the floor, then you can spread the subwoofers wider apart (like under your L/R speakers). With an irregularly shaped room like you have (and I have), the only way to know the optimal subwoofer locations is by measuring their combined frequency response. Short of that, spreading them apart will help. The room correction in the receiver will further help to smoothen the response. Down the road, consider bass traps for some of the corners. BTW, if you do wall mount your left & right speakers, try to get them to roughly the same height as your centre speaker; when a truck drives from across the screen, its sound won't move up and down as it pans from the left to centre to right speaker.

Did I mention your latest layout looks awesome?

Happy Thanksgiving to you too.
post #10 of 11
Thread Starter 
Thanks a lot for all your help Sanjay! I seriously appreciate it. I've started my next thread looking for speakers. I think wall mounting is a good idea so the subs can be spread further apart. Once I decide on the speakers I'll draw a final layout with their exact sizes and placement. The new thread is here: Need 5.2 - Bookshelf/Monitor - Wall Mounted/Close to Wall - $4000 to $5000

Thanks again Sanjay.
post #11 of 11
You're welcome. Good luck with the project.
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