SPCR

It has not been an interest of mine, personally... till recently. I've been doing research on the topic for several months, and just had the opportunity to hear some in a home setting. Yes, hear, not just see.

Probably, those who are into this already know it well, but every rear projection TV has at least one cooling fan that runs constantly. Most big plasma TVs have them as well. It appears that some LCD TVs (up to 40" anyway) don't have them, but many do.

Just how much noise are we talking about? It appears to vary quite a bit.

I recently measured the SPL of a Sony 42" LCD rear projection TV (KDF-E42A10) in a small quiet room. Without the TV on, at the viewer seat 2 meters away, it was 20~21 dBA. When the TV was turned on with the sound muted, it measured 29 dBA. The noise was mostly broadband, but from under 1m distance, I could hear some higher pitched sounds -- like electronic whine of some kind.

Turning the TV sound on at a fairly modest volume, movie/TV dialog ranged 30~45 dBA. This would be a bit louder than when you're staying up late watching TV while someone else in the house is trying to sleep. Someone in an adjacent room might hear it, but not two rooms over. Sometimes the fan noise could be heard in quiet portions... though it's hard to describe it as being terribly intrusive. If I was watching a movie, it's highly unlikely that the fan noise would ever intrude -- the point of a HT/HDTV system being to have great sound for the movie, which usually means you turn it up considerably louder than 30 dBA average.

If the volume is set so that dialog in a typical movie is set to peak no higher than 50 dBA (pretty modest as mentioned above), when music in the soundtrack kicks in, it easily reaches 55-60 dBA. Turn up the volume to get a more satisfying experience, and the peaks jump easily to >80 dBA. At this point, the 29 dBA residual noise of the TV/fan is totally irrelevant.

I bring up this issue for several reasons because if the above is typical, then concerns about <30 dBA fan noise are only relevant to picky folks who want silence when they mute the commercials. On the other hand, if other TVs are much louder, then maybe it's worth turning this post as the start of a user poll on HDTV noise.

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I've decided to go ahead and run a poll.

I have a rear-projection TV (Toshiba 42H83) which has noise similar to what you describe, but it doesn't bother me (ambient noise in an urban high-rise apartment building takes care of that). What is more likely to bother more people is the fan(s) in the A/V rack - the fan in the back of my cheapo DVD player - home-theater-in-a-box is the loudest thing. Next is the Sony PS/2, when it's turned on. Next was my TiVo Series 2, before I replaced it with the MythTV machine described below.

My Samsung hp-r5072 50" plasma does't seem to have a fan, but if you put your ear right up to the TV you can hear the buzzing from the current running through the plasma screen.

A friend of mine has a Toshiba 42" DLP which apparently has 2 fans. One is set somewhere inside the box and isn't noticeable but the other is near the outside and is unreasonably loud. It's a 92mm NONOIse, unsure of model number. It barely pushes any air but makes quite a racket.

personally, I've got a 36" direct-view Toshiba HDready 4:3 perspective outputs 480i, 480p, 720p and 1080i. Thanks to it being a tube, it's dead silent. But dam is it heavy, about 224lbs. I still cringe at the memory of taking it up a flight of steps…

then there's my friend, who has a BenQ pe7700 DLP projector, which does 720p native. there are two settings on it, 'economy' for slightly dimmer picture, longer bulb life and slower fan speed, review sites claim 26db and 'performance' for brighter picture, bulb lasts about 25% less and fan speed kicks up to about 29db.

Ive got a Acer AL2671W HDTV 26". And that’s completely silent from any real distance. just to add my 2 cents.

What about ordinary TV? I have a Thomson 32" WS TV, no HDTV since HDTV isn't even broadcast where i live.

When in standby mode, it makes a very intrusive "hum", lice the standard 50Hz hum that you can experience when you have ground loops. I have however tried disconnecting the tv from everything but the power source and it doesn't help at all.

When on and with no sound, like when using TV-out from the computer, it is unreasonably loud. Especially when viewing light objects like opeining an explorer window.

This looks like the kind of sound that you won't get rid of so easy and it is a shame, since it is way louder than my "silenced" computer.

shades_of_blue wrote:personally, I've got a 36" direct-view Toshiba HDready 4:3 perspective outputs 480i, 480p, 720p and 1080i. Thanks to it being a tube, it's dead silent. But dam is it heavy, about 224lbs. I still cringe at the memory of taking it up a flight of steps…

then there's my friend, who has a BenQ pe7700 DLP projector, which does 720p native. there are two settings on it, 'economy' for slightly dimmer picture, longer bulb life and slower fan speed, review sites claim 26db and 'performance' for brighter picture, bulb lasts about 25% less and fan speed kicks up to about 29db.

HOLY CRAP that's heavy!!


DLP's having moving parts going at sick speeds in them. You CAN hear them even though they have gotten much quieter. THat colour wheel thing. I could understand how they would have fans in them as well. I sell TV's and other appliances, those plasma's definitely are named more for their heat than anything else. They have convection holes though that breath air in. Identical to the design of a iMac single screen all in one computer. The plasma's do get hot though. I always thought that a nicer heatsink design would cool them better. That heat cant be good for helping them last 20 years. (that's how long they are supposed to last now in generation 8+ of plasma world)

My rear projection HDTV is absolutely silent. It's a CRT model with 7" tubes. No fans. No moving parts. While there might be some coil noise SOMEWHERE in there, the entire beast is encased within a very large sturdy wooden body with no gaps. If there's any coil noise, it has no escape pathways so you can't hear it even if you put your ear against the TV.

Too bad the cable company's HD DVR has a 3.5" hard drive in it!

my gosh it's full of stars!

Those are known as monoliths. I have sold the last ancient ones off the floor at my electronics store finally. they still make them and sell them for 1100 dollars NYC price, hitachi makes them and someone else.

I knew dlp's had moving parts, but now I will ahve to listen to the rest of the big, sub 2000 dollar 42inch lcd projection ones to see if they have a fan.

I believe that SXRD, the new double the pixel count lcd projections from Sony (just came out), do not have a fan to my knowledge

We had a Panasonic VIERA series 42" plasma(~3500€) some time ago for a couple months for review, it did have a fan but it wasnt audible when watching a movie. Maybe under very quiet scenes in a movie, but not loud enough to be a distraction. From 50cm or closer i did notice electrical noise, but i couldnt say exactly where it was coming from. No complaints on the picture quality... It had pretty decent speakers for a TV too, i ended up using them instead of the Logitechs most of the time actually because they sounded better but obviously lacked more in the bass department.

The 32" Samsung LCD we had for the same time was silent, no complaints on the imgae here either.. Only minus is that it´s so damn small at only 32"

Can´t remember the exact model numbers but both were on the expensive side but not neccesarily the absolute top of the range.. This was something like last fall, and both were just about to hit the stores when we had them.

And btw. Sharp has just released a 65" LCD screen capable of 1080 progressive scan.. Biggest LCD in the world atm? What´s the biggest plasma? last time i checked it was a bit over 80"..

I'm worried about the future of HDTVs, the transmission standard HDMI requires encryption for HDTV content, and we'll probably get the shaft when manafacturers choose shoddy decoders and loud cooling systems.

I second this. even though this is an older post.

HDTV could be good, but the decoding aspect and compression of it could make it rather crappy.

yeah the 65 inch 1080p sharp is sick I bet.

makes me gleeful