IR? Line-of-sight? Really?? - AVS Forum
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Old 01-08-2011, 10:22 AM - Thread Starter
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Ok, I've spent an hour searching the forum, and surprised I don't see the question/answer.

Why in the hail would you make glasses sync via IR? I was about ready to pull the trigger and buy a VT25, then I saw how low the emitter was on the bezel, and how easily it was blocked by a center channel speaker.

Is it really that expensive/heavy/complicated to use radio freq.? I understand that limited bluetooth options exist, but can't understand how/why line-of-sight IR was so widely chosen. And why would you not put the emitter on the top bezel? This seems pretty brain-dead to me.
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Old 01-08-2011, 10:49 AM
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hot-link.com has some very good IR repeaters.

99.5% Dark Matter
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Old 01-08-2011, 02:37 PM
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It apears that some of the 2011 3D TVs are using Bluetooth or RF instead of IR to avoid the problem that they have with using IR and having the engineering design ability to put the IR emitter in the top of the bezel instead of in the bottm.
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Old 01-08-2011, 06:45 PM
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Because the 2.4GHz band is jam packed with devices along with general RF interference, and you can't afford to lose the connection for more than about 20ms.
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Old 01-09-2011, 09:22 AM - Thread Starter
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Quote:
Originally Posted by poppabk View Post

Because the 2.4GHz band is jam packed with devices along with general RF interference, and you can't afford to lose the connection for more than about 20ms.

Mmm, not really buying that. PS3 controllers and remote work flawlessly over bluetooth. And as far as 20ms goes, that means any errant hand, or a bag of chips, not just an obvious center speaker placement, can get in the way of IR. And I still can't think of a reason why you'd not place the emitter at the top - or heck, have more than one. Have money, willing to jump in, but for 3 grand I expect a little better.
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Old 01-09-2011, 09:41 AM
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The IR is not going to have interference from any of the any RF bands in use around the home today. If you look at how far from center your wireless mouse and keyboard work I think you'll see that the active 3D glasses will work within the same viewing angle as was recommended by the TV manufacturer so view the picture properly.
Unlike the passive 3D glasses, the active 3D glasses allow you to lay sideways as you would on your couch or and have your head tilted in your east chair.
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Old 01-09-2011, 10:57 AM - Thread Starter
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Originally Posted by JGTravelor View Post

The IR is not going to have interference from any of the any RF bands in use around the home today. If you look at how far from center your wireless mouse and keyboard work I think you'll see that the active 3D glasses will work within the same viewing angle as was recommended by the TV manufacturer so view the picture properly.
Unlike the passive 3D glasses, the active 3D glasses allow you to lay sideways as you would on your couch or and have your head tilted in your east chair.

Well, not to beat a dead horse, but bluetooth frequency-hopping seems to handle any interference just fine, and there are too many cases where I can envision IR being interfered with. And I think Samsung's decision to go all-bluetooth this year says a lot. The bottom emitter on the Panny was just a bad call, IMHO, and combined with the ugly bezel it was enough to put me off the sale when I was literally in a Magnolia with wallet in hand.

And I have no argument at all with active over passive.
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Old 01-09-2011, 01:42 PM
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Quote:
Originally Posted by guerojose View Post

Mmm, not really buying that. PS3 controllers and remote work flawlessly over bluetooth. And as far as 20ms goes, that means any errant hand, or a bag of chips, not just an obvious center speaker placement, can get in the way of IR. And I still can't think of a reason why you'd not place the emitter at the top - or heck, have more than one. Have money, willing to jump in, but for 3 grand I expect a little better.

Do a google search for PS3 controller interference and you will find plenty of people with problems, and 20ms interference that only occurred once every 30 seconds wouldn't be obvious in a controller. My wireless speakers interfere with my wiimote, which is only noticeable at certain points when the polling is increased. I agree that they should have more emitters though.
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Old 01-09-2011, 02:37 PM
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You can have IR interference from regular flourascent or compact flourascent light bulbs
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Old 01-09-2011, 03:09 PM
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You can have IR interference from regular or compact flourascent light bulbs

I haven't heard of many people having IR interference problems from light bulbs although it could happen. It is interesting that Samsung are the ones going to bluetooth, and they are the ones who have had trouble with their plasmas producing IR sync issues. Personally I think they should have gone with a dual bluetooth/IR system, maybe in a redundant configuration.
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Old 01-09-2011, 07:19 PM
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I don't like how the emitter pretty much eliminates my ability to use the remote for my projector. In a perfect world I wouldn't have to make minute picture adjustments when watching a movie, and considering no matter where I place the Nvidia emitted, the signal still blocks the projector's remote even when I place the remote less than 1 foot from the PJ (short throw GT720).
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