CurtPalme.com Home Theater Forum

[lyd]

Hello again, everyone.

It looks like I am in for an 8500 with HD144 lenses.

So I am trying to nail down the geometry of the situation now.

I have read the primer numerous times, of course, and looked at a lot of other information as well, but the inconsistent use of horz. vs diag. measurement in these discussions has me a bit thrown.

So, first off, am I correct in understanding that the maximum reasonable screen size for an 8" is 96" horizontal?

If so, that puts my mount point at right about 10 feet, which is good, because I have this huge commercial-style fluorescent light fixture on my celling at that point. I am thinking that, rental be damned, I can take the fixture down, put my mount up, and I won't even need to worry about patching drywall when I move, just putting the fixture back up.

Optimum seating distance should be about 12', if I am still doing the math correctly.

Okay, this is all great so far, unless I need to be corrected on any of those assumptions, but here come the problems.

I was thinking of going 4:3 with the screen, and I have the height for that, but I had also recently been thinking of going with 3 floorstanders across the front for LCR. These two thoughts are mutually exclusive.

16:9 would be good fit, however. I currently watch maybe 40% 4:3 content. Once I have HD capabilities this may be less, but not tons less, I'd think. So I was worried about phosphor usage. Any thoughts on this? (I suppose I should note that while I will sometimes, even frequently, watch 15 - 20 hours over a weekend, I will seldom watch more than a couple hours a day during the week, and frequently not at all. This could be either 16:9 or 4:3, depending on whether I have a load of movies or am catching up on multiple episodes of some TV show I like.)

The third option would be a smaller 4:3 screen, of course.

I need at least 44" off the floor to do the 3 floorstanding speakers. This is higher than it should be, I know, and by a significant margin, but I tend to watch in a more or less reclined and neck-supported mode anyway, so I am thinking it won't be an issue for me. It will put the bottom of the screen just at or slightly above (depending on seating) eye level. I know that I could build platforms, but if I do that it won't be soon.

I have really become frightened of the default mid-tweet-mid sideways center channel design, after reading several articles documenting the problems with this approach, hence the three identical units across the front. Still, the last option remains going with that design anyway, possibly placed vertically rather than horizontally.

So, mistakes in my base assumptions notwithstanding, it comes down to a choice between an audio compromise and a viewing compromise. Does anybody have an opinion?

lyd

[BubTheZombie]

Dude, I agree with everything you say but a 4:3 screen that far off the floor? Sheesh, the top of the screen is going to be 9ft 8inches off the floor. Middle of the screen is going to be nearly 7ft high. I would undoubtedly go with a 16:9 screen. All movies, games and TV are made / shot that way now (OK, apart from IMAX ;o) ). I hear that whilst most TV is shot in 16:9 it is actually framed for 14:9 as a compromise between the two formats and the folks at home with different shaped TV sets so perhaps you could blow up your TV watching to 14:9? Is is only old shows that you watch that are only available in 4:3? You only want to mechanically set this bugger up once if you can help it. The future is all 16:9. And it would accomodate your 3 floor standers by the way. (Having 3 of the same for front speakers and floorstanders to boot is the best move you could make). Finish it off with a nice modern 16:9 screen. We're all looking for that cinema effect but there's a reason the front row seats go last.

Have fun anyhow,

Rob

[lyd]

I am thinking you are right about going with the 16:9 screen, whatever else I do. I'll just live with the wear when projecting 4:3 inside that, and try to find more of the stuff I want to watch in a wider aspect. Or grit my teeth and watch it on the old 27" tv.

It turns out I was rather significantly wrong in all dimensions when I estimated the size of this room. Not enough to spoil any plans, but smaller none the less. I got around to measuring today, and this is what I am actually working with.




Thanks for the response.

lyd

[lyd]

I've decided on three of the RBH TK-5CT's across the front, and a 16:9 screen. That should leave my front stage looking more or less like this.



I think I am going to go with a DIY Wilsonart screen, and do a manual masking system based on magnets behind the screen and felt-covered bits of metal on the back of the masks.

If anyone has any further suggestions at this stage, I'm all ears.

Thanks.

lyd

[KnottyMan]

What software are you using to generate those drawings? Looks nice and clean.

[Joust]

looks like sketchup to me.
if not then this works just as well.

http://sketchup.google.com/

[ecrabb]

Yep, that's Sketchup... Every home DIYer's dream software - excellent for DIY HT designers. It would be a great tool for $100 or $200... but it's FREE!!!

lyd, I have the same screen size - 96x54. I set about 1.1-1.2x screen widths away. When you see how pathetic 4:3 SD cable or satellite or whatever looks, you'll either hate it so much, you'll watch less of it... you'll hurry up and get HD (my vote), or you can also use a source or scaler to zoom or stretch the 4:3 to eliminate wear. I mean, it already looks crap, anyway - might as well stretch or zoom it to fill the screen.

All that said, I still don't think I'd want my screen 3.5 feet off the floor. Your head will probably barely be at that if you're in any sort of sofa/recliner. That puts the top of the screen at about 8'. Hmmm... So, what have you heard that's sonically so bad about a horizontal center? I don't remember what it was anymore, but I guess I do remember there something being sub-optimal about the MTM design on its side... but, I don't remember it being a show-stopper.

SC

[lyd]

[ecrabb]

Ah yes, off-axis lobing. I remember that now. M&K supposedly mitigated that effect in the center design that I own by using a special grille and a TMM configuration instead of a MTM configuration. I wonder what the truly audible result of the off-axis lobing

I'm no super audiophile by any means, but I do know a good system when I hear it. I haven't treated my room yet, but my system still sounds excellent so far. My LR mains are mounted on stands at sitting ear height - tweeters at just above ear hight, mids below. The center is directly below the screen, angled up, probably at around 2' off the floor. I know center performance suffers somewhat in the back row, but I don't have the room depth to go audio transparent, or the wall height to raise the screen anymore.

If you have your heart set on the RBH floor standers, why not just go with the center you linked to and use it vertically, maybe a foot or two lower than the mains. I can't imagine imaging or sound stage would suffer that much, if noticeably at all.

SC

[lyd]

Okay, I appreciate all the input.

What I have decided to do, realizing that I planned to buy a pair of the TK-5C bookshelves for surrounds at some point anyway, is to buy them right away and use one for the center and throw the other in as a rear center.

This way, I can position the screen at a more standard height, see what I think of the sound, and if I decide to do something else for the center I can just move the 5C's into duty as the surrounds. If I am happy with it I will buy a second pair of 5C's.

Looking at the specs, I can't see how 515C center differs significantly from the 5C bookshelf besides the former having the MTM design.



System Type: Bookshelf, 2-Way Bass Speaker
Frequency Response: 60Hz-20kHz (±3dB)
Sensitivity: 86dB (2.83V @ 1 Meter)
Recommended Power: 50-100 Watts
Drive Units: (1) 5 1/4" (133mm ) Fiberglass Cone Woofer
(1) 1" (25mm) Silk Dome Tweeter
Tweeter Protection: Yes
Crossover Frequency: 3000Hz
Crossover: 12dB/Octave


System Type: 2 Way Bass Reflex
Frequency Response: 60Hz-20kHz ±3dB
Sensitivity: 89dB (2.83 Voltz @ 1 Meter)
Recommended Power: 60-120 Watts
Drive Units: (2) 5 1/4" (133mm) Fiberglass Cone Subwoofer
(1) 1" (25mm) Silk Dome Tweeter
Tweeter Protection: Yes
Crossover Frequency: 3000 Hz
Crossover Slope: 12dB/Octave


lyd

[lyd]

I'm not sure if anyone is remotely interested at this point, but this is where my plan sits at the moment.



Trying to figure out how to handle the surrounds at this point. They are rear-ported, but I am hoping I can still put them on shelves up on the wall, just spaced out from it by a couple of port diameters. Anyone have a thought on that?

lyd