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Silent TFT?

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September 18, 2002 1:09:20 PM

im looking for a 17" TFT monitor for a silent PC system. any suggestions? ive heard not all TFT's are silent.

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September 18, 2002 1:39:28 PM

What noise can a monitor make? Aren't they all silent? They don't have fans or anything that makes noise.
Are you building your PC with water cooling? Just wondering.

My DVD reader is destroyed! I told you it wasn't an oven!
September 18, 2002 1:45:58 PM

Actually, crt's are kinda loud (well that matters in say music studios where absolute silence is necessary) since upon turning on they usually make a noise, and can from there keep whining (i notice it at least, that's how I know if a tv or crt is on). TFT monitor generally are silent, so you don't need to really worry about noise from them- the bigger question is what will you be using it for?

What if you had admin rights to life?
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September 18, 2002 2:32:59 PM

basically im just one of those freaks who wont be happy until their system is totally silent. at the moment ive got a 19" CRT and the buzz from it is getting more and more noticeable as the rest of my system gets quieter. but i dont wanna fork out for a TFT if the buzz will be just the same.
September 18, 2002 7:56:32 PM

lol, it won't be. I dun mind my crt much b/c it's pretty silent and I'm almost always playing music so I can't hear it anyway. Now, for finding the right LCD, what's ur price limit, and what size do u want?

What if you had admin rights to life?
September 18, 2002 9:37:29 PM

ive always been a fan of Iiyama, the AS4314UT looks nice, does anyone recommend it?
September 18, 2002 9:44:28 PM

Definetly not. For 17", Samsung 170T or 172T.

What if you had admin rights to life?
September 20, 2002 2:35:59 PM

i cant find those samsung models for sale, only the 171S (im in UK). is 171S just as good? theres also a 171P designed by Porsche (wots that all about?)
any specific bad points about the Iiyama?
September 21, 2002 5:39:07 PM

Oh yes, a monitor can make noise. That was one of my main reasons going TFT. My TFT (Eizo l365) also makes a little high pitched hiss like noise, but it is much less than my old CRT.

As Flame says somewhere else in this thread. CRTs can make high pitched "singing". When I walk on the street and I pass close by a house - if the window is open, I notice a television, that other people do not notice. It is very individual how well people persieve high frequenzy sounds. And it the amount of "leaking" sound from a monitor/TV varies a lot. Personally I find AOC CRT monitors are often very anoying in this perspective. I have sometime left a room because of an AOC screamer.
September 21, 2002 9:42:43 PM

CRT buzz is irritating. I guess it comes from the HT circuits so TFT's won't suffer. Certainly, my Samsung 150mp and LG Flatron TFT's are absolutely silent.

The screen on my Compaq laptop sometimes emits a very high-pitched whine (around 15khz I think) which drives me crazy. Reducing the screen brightness fixes it, thank [-peep-].
September 24, 2002 10:56:20 PM

Whats wrong with the Iiyama? I was looking at getting the AS4332UBK. Is this any better? If not it's going to have to be an LG L1800P but this is over £100 more. Is this one ok? I wont use the LCD for games and the like, Its just as a second monitor on my main sys and first on my server.
The main monitor is an Iiyama 454 pro and I thought a second one might complment it. (Well any thing is better than my compaq 1024 that I have at the mo for my second!!)

Now thats what I want to know!
September 26, 2002 6:13:31 PM

the audible noise of an LCD-TFT monitor is coming from the "back light inverter". This inverter generates the power to drive the lamps of the monitor. To reduce the brightness of the lamps the power flowing to the lamps must be reduced. This is usually done by "pulse width modulation" (=PWM). Simply speaking, the lamp is turned on and off very fast. Making the off time longer and longer makes the lamps darker and darker, the brightness is reduced. If the frequency of the on and off period is high enough you cant see the switching of the lamp.
Unfortunately, the frequency at which this takes place is usually in the range of some 100Hz. The result is some "feeping" noise you can hear.
The noise is dependent on the brightness and is usually best heard at low brightness levels.
There are backlight inverter which don't use PWM. This is then called analog dimming. These inverter are noise free. The problem is that the dimming range of analog dimming is smaller than PWM dimming. This is why you normally find PWM dimming in monitors.
Unfortunatly, the way how the dimming is done is not listed in the monitor specs. So the only way to find out is to open the monitor and to look at the backlight inverter.
Of course this is impossible if you buy a new one.

I'm sure all monitor manufacturers are aware of this but most of them just don't care. The primary reason for this is that they say they have no complaints about audible noise.
The only way to improve this situation is to give the monitor back if you find this noise annoying. If more and more customers complain about this it will be changed.
From a technical point of view the noise can be avoided if this is required.

If you want to know more about tis technical stuff look at the specs of a typical backlight controller like the O2Micro OZ965 http://www.o2micro.com/products/OZ965.pdf
October 1, 2002 12:35:01 AM

I'm so glad I read this thread before ordering two TFTs... I'm also going down the ultra silent route with a SID Futureclient fanless PC. The plan was to stick a couple of Eizo L565s with it but if they generate noise I'm gonna be really upset. Has anyone got an L565 and if so does it make a noise at all?

I currently have an Iiyama 510 crt which I think is totally silent (it certainly is in standby and I can't hear it over the noise of my PC otherwise. I don't want to replace it with something noisy!

Any comments welcome, I was going to order the Eizos tomorrow.
!