Samsung SyncMaster 931BW

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Samsung SyncMaster 931BW

Post by MikeC » Thu Jul 19, 2007 11:11 am

The Samsung SyncMaster 931BW is a modestly priced wide screen 1440x900 LCD monitor with both Analog RGB (VGA) and DVI inputs and a claimed response time of 2ms. This review is a kind of spot check on what most SPCR readers assume to be facts: That modern LCD monitors have very good performance, great fit and look on the desktop (and elsewhere), make no significant noise, draw little power and produce little heat. Is this true of the 931BW?

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Post by jojo4u » Thu Jul 19, 2007 1:22 pm

Nice to see you reviewing some other devices. A bit of what you fancy does you good ;) But now on to some core competences of SPCR :)

Btw, 8:5 is quite uncommon to say. I got confused since I only know 16:10 (allows comparing to 16:9).

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Post by NeilBlanchard » Thu Jul 19, 2007 5:14 pm

Hello Mike,

The chart on the second page says 19" wide -- would that be 19" diagonal?

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Post by cloneman » Thu Jul 19, 2007 5:56 pm

It's definitely a diagonal measurement.

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Post by Matija » Thu Jul 19, 2007 11:48 pm

You forgot to mention that the 931BW has a TN matrix (although the declared 160 degrees viewing angles give that out). This makes it unattractive to a lot of people.

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Post by Capsaicin » Fri Jul 20, 2007 6:08 am

Matija wrote:You forgot to mention that the 931BW has a TN matrix (although the declared 160 degrees viewing angles give that out). This makes it unattractive to a lot of people.
QFT.

Could we get a similar review of an LCD with an IPS panel (or PVA/MVA)? Or at least clarify that the visual-quality portion of the review is purely subjective (or did you use any monitoring equipment you're not mentioning)?

The power/noise portion of the article is great, though. :D

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Post by Tzupy » Fri Jul 20, 2007 8:28 am

Maybe this particular cheap monitor is almost silent, but there have been reports in the forums on high-pitched noise from other Samsung LCDs, especially when the brightness is lowered. It would be good if SPCR would investigate the noise issue for other - more capable - monitors than this cheap TN 19". If a cheap moitor is noisy, it's not a big problem to sell it to someone who is not so noise-sensitive. But when one buys an expensive LCD, like the NEC 2690 WUXi (H-IPS panel) - a known buzzer, at least the first batches, then it's a big problem.

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Post by MikeC » Fri Jul 20, 2007 8:31 am

Matija & Capsaicin,

Given that TN technology dominates the popular market, it did not really seem necessary to delve into. AFAIK, all monitors in this price range have to be TN; the cost demand dictates this. If TN makes this monitor unattractive to a lot of people, then it would seem that in your view, Matija, all cheap LCD monitors would be unattractive to a lot of people.

And yes, my assessment was entirely subjective, but I also have 5-6 other LCD monitors to compare with, the newest being less than 1 year old. I don't expect to address all the demands of videophiles with this review. A few other sites already have very good systems in place for reviewing monitors completely; I have no desire to compete with them. Keep in mind my main goal: A spot check on LCD monitor noise & power consumption, primarily.

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Post by jessekopelman » Fri Jul 20, 2007 10:53 am

About the lack of APFC -- I wonder if this is because of the way the backlight brightness is controlled. One would assume the majority of draw is due to the backlight lamp. I have a few halogen lamps at home and when set to full brightness they have a PF of ~1, but when the dimmer function is used the PF goes down to ~0.67.

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Post by MikeC » Fri Jul 20, 2007 11:31 am

jessekopelman wrote:About the lack of APFC -- I wonder if this is because of the way the backlight brightness is controlled. One would assume the majority of draw is due to the backlight lamp. I have a few halogen lamps at home and when set to full brightness they have a PF of ~1, but when the dimmer function is used the PF goes down to ~0.67.
You are right that the typical LCD light is a Cold Cathode Fluorescent Lamp -- commonly referred to as CFLs. These definitely are not purely resistive. AC CFL replacement bulbs measure something like 0.6-0.7 PF, so your guess is right. However a correction circuit can be added to any device to improve its power factor. It goes between the AC input and the main circuitry. That's what PFC and Active PFC are about.

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Post by JazzJackRabbit » Fri Jul 20, 2007 11:31 am

I'm not sure how appropriate monitor reviews are for spcr. There are two things I'm interested in monitors, one is usability/colors/viewing angles and other standard stuff, basically what every person looks for in a monitor and two which is whether or not it buzzes or gives off any audible sound signature.

While it's nice to see spcr test monitor for quietness, the review goes on to review the usual stuff but stops half way. I don't blame spcr because they obviously don't have sophisticated hardware to test monitors, but IMO either go all the way and review monitor completely or just do the sound measurements. For spcr purposes I'd prefer the latter because that way we either get more reviews that are relevant to silence or Mike can simply spend more time on other more appropriate articles.



BTW, I don't know if it's the same for 931BW, but my dad owns 926BW and it is fvsking annoying. First, when monitor goes into standby when you turn off your computer, the power led starts blinking every second. This in itself is super annoying. Why Samsung couldn't just install dual color led and turn it red or yellow to indicate monitor is in standby, why do they insist on bling blinking? Second, I think half of the power consumed by the monitor must be going to light the power led. It is so bright that in the night it illuminates half the room (I'm not kidding here, think sunbeam rheobus blue leds kind of brightness). It's not so bad during the day, but if you intend to put it in the same room you're sleeping, be prepared to manually push power button on your monitor every night.

It's funny how such a small thing like that can be so annoying, but it is. If I were to buy a new monitor, this alone would be enough to cross it off my list of potential purchases.

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Post by Matija » Fri Jul 20, 2007 1:43 pm

Hey Mike, I'm just sayin'... I don't think anyone from here would rush out to buy the 931BW just because of the SPCR review :) Interesting test, though. In the quest for silence, monitors can be troublesome.

But don't underestimate the view people have on computers. I used to work in a medium-sized company (roughly 4000 employees and a couple of thousand computers) and I've seen hundreds of CRT monitors running at 60 Hz and flickering like mad. When asking people if that bothered them, nobody (and I mean nobody) could even see it. The only thing that mattered is that there was a picture displayed, and a desktop wallpaper with a cat/dog/child. I have even seen Cleartype on 800x600.

Likewise, few people notice that something is "wrong" with their TN LCD. They either don't see the observed colours change based on the viewing angle, or they think it's normal. Last week, I took a friend to a computer shop with lots of LCD monitors on display to show him the differences between various types of matrices. He thought his TN (not that he knew he had a TN) was like all other LCDs... Now he's buying an S-IPS.

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Post by Aris » Fri Jul 20, 2007 8:10 pm

well i'll give you this, its about time this site did a review of something. its been too long. ECO PC links on the main page dont count as reviews IMO.

the way i see it, there are just too many LCD's to realistically do any sort of comprehensive noise/power LCD review "stuff" to make it worth it. a random monitor here and there really doesnt say much unless that specific monitor is the one you have your heart set on, which wont be many people.

Also considering the testing methodology is primitive, at best, i would say just stick to what your good at. PSU's, Fans, Hard Drives, Cases, and the accessories that go with them that effect how quiet they are.

Please PLEASE, whatever you do, dont go the way tomshardware did and become this comglomerant of everything technology. Stick to what your good at, and do the best at that and nothing else.

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Post by jessekopelman » Fri Jul 20, 2007 10:14 pm

MikeC wrote:
jessekopelman wrote:About the lack of APFC -- I wonder if this is because of the way the backlight brightness is controlled. One would assume the majority of draw is due to the backlight lamp. I have a few halogen lamps at home and when set to full brightness they have a PF of ~1, but when the dimmer function is used the PF goes down to ~0.67.
You are right that the typical LCD light is a Cold Cathode Fluorescent Lamp -- commonly referred to as CFLs. These definitely are not purely resistive. AC CFL replacement bulbs measure something like 0.6-0.7 PF, so your guess is right. However a correction circuit can be added to any device to improve its power factor. It goes between the AC input and the main circuitry. That's what PFC and Active PFC are about.
Agreed. It just doesn't seem like this is a common implementation in low cost lighting. So, while you are right to call out Samsung for not using APFC, you might want to research whether this is a common failing of LCD monitors.

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Post by Brainiac 5 » Sat Jul 21, 2007 4:34 am

Tzupy wrote:Maybe this particular cheap monitor is almost silent, but there have been reports in the forums on high-pitched noise from other Samsung LCDs, especially when the brightness is lowered.
Yes, I'd be interested in whether the monitor was tested with the brightness turned down. I have a Samsung 940T, and it emits a high-pitched sound when the brightness is turned down below around 70% - louder the more you it down. It is extremely noticeable, so it would appear that not all LCDs are silent under all conditions.

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Post by MikeC » Sat Jul 21, 2007 8:00 am

Brainiac 5 --
As noted in the power table, the brightness during testing ranged from 0% to 100%. There was no detectable change in noise.

jessekopelman --
I checked the two 19" LCD monitors on my desk -- a BenQ and a Gateway -- and they both show the same bad PF characteristics. There are two more to check. I have a bad feeling about this. :?

Funny thing is that these are all Energy Star approved, and the new computer spec calls for 0.9 PF... but afaik, the new spec does not extend to monitors or any other IT gear other than computers themselves.
Last edited by MikeC on Sat Jul 21, 2007 9:19 am, edited 1 time in total.

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Post by Felger Carbon » Sat Jul 21, 2007 9:06 am

MikeC wrote:afaik, the new spec does not extend to monitors or any other IT gear other than computers themselves.
Perhaps the thought is, the monitor PF will be swamped by the much larger computer case current draw.

I'm typing this on a computer that's drawing, let's see... 43W right at this moment, and the last time I measured my 19" LCD monitor (lowered intensity) it pulled 35W. So much for the computer case drowning out the monitor (if prices come down, I'll buy a bigger monitor).

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Post by Tzupy » Sat Jul 21, 2007 9:35 am

Since my previous post didn't get any SPCR answer, I'll reformulate / expand it:
I see little point for SPCR to test a few average LCDs in all quality aspects.
I would by large prefer that SPCR tests many good LCDs noise-wise (and for annoying lights too).
As for which are 'good' LCDs, this 'The LCD Thread' at Anandtech forums would be a good start IMO:
http://forums.anandtech.com/messageview ... erthread=y
I know it may be difficult to get (not buy) the expensive LCDs for testing, but maybe you can find someone to help with this issue.
My suggestions for cheap LCDs would be: Acer 2051W (glossy P-MVA, the others are TN), LG 226WT*, HP w2207, Samsung 226BW.
It would be nice if SPCR could find out WHY some LCDs get noisy when lowering the brightness.

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Post by jaganath » Sat Jul 21, 2007 10:19 am

It would be nice if SPCR could find out WHY some LCDs get noisy when lowering the brightness.
I'm fairly sure it's caused by components associated with the inverter. PWM is used to control voltage fed to the CCFL, and when frequency of this comes into audible range it results in the high-pitched noise one can hear. There's not much can be done about it,apart from get a different LCD.

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Post by Tzupy » Sat Jul 21, 2007 10:30 am

You mean that by lowering the power (when lowering brightness) the frequency drops from ultrasonic to human range?
That would mean that the noise is always there, but only at lower power it can be heard (by humans).

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Post by dhanson865 » Sun Jul 22, 2007 11:04 am

I am using an ACER AL1916W which is the same size and resolution as the reviewed monitor but was on sale last week for $139. Seems like a fair deal to me (though I paid more for it some time back).

FWIW I tested with a Kill-a-watt when I first got it and power on this monitor is about half and half between the backlight and the rest of the LCD/support circuits. I also noticed the lack of Active PFC. I'm assuming all LCDs will lack that feature.

I didn't notice any noise whatsoever from the LCD no matter what brightness level I chose and I stepped through all the levels 1% at a time with 15-30 seconds between the levels just to see.

I finally settled on leaving it at 50% brightness and haven't bothered to change the brightness in several months now.

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Post by charger2000 » Mon Jul 23, 2007 6:09 am

Hi, forgive me but I don't get the point in an LCD review on SPCR

:?

Nik

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Post by Brainiac 5 » Mon Jul 23, 2007 6:34 am

Since some LCDs (unfortunately including mine) do emit noise, I'd be happy to see more LCD reviews, or at least information about noise on various models.

And by the way, thanks to Mike for setting me straight about my question above, that's exactly the information I was interested in.

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Post by croddie » Tue Jul 24, 2007 10:41 am

Yes you can't conclude from one monitor that LCDs are noiseless. Some are very audible.

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Post by Elixer » Sun Jul 29, 2007 2:59 pm

I'm in agreement with the others in that the idea of SPCR reviewing monitors doesn't really make sense. Unless SPCR is able to review a large number of LCDs and make some judgement about noise, it doesn't make sense to me. If you test 10 LCDs and some of them make audable noise, then you're getting somewhere, but testing one that doesn't, doesn't help us very much.

I think SPCRs time could be better invested in say, an extremely large listing of fans, with noise measurements at 12, 9, 7, 5, and 4V and also with personal reflections on the fans. This seems to be something that SPCR is lacking.

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Post by Kaleid » Mon Aug 13, 2007 4:07 pm

I bought this monitor a couple of weeks ago but had to return it since I wasn't really aware that TN screens have so bad viewing angles and on top of it all it made a rather high pitchy noise.

So I read a bit about different panels and went with a far superior S-IPS Philips 200WP7ES instead. Far better viewing angles, better contrast (still worse than Samsung 959NF CRT though) and it's completely quiet. 8ms response time but it seems to be enough for the few games I play these days.

Gotta say that I love the sharpness of this Philips TFT screen, certainly puts my old 959NF to shame...

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Post by Longbow » Mon Aug 13, 2007 5:23 pm

Elixer wrote:I'm in agreement with the others in that the idea of SPCR reviewing monitors doesn't really make sense.
maybe.

Clicking / popping noises coming from Dell LCD monitor
viewtopic.php?t=42665&highlight=

at least i know this samsung didn't have such problem in the lab
You forgot to mention that the 931BW has a TN matrix (although the declared 160 degrees viewing angles give that out). This makes it unattractive to a lot of people.
it's a budget model, and most budget models use TN panels. the price and qualify improvement over the years indeed are attractive to most targeted consumers.

the best advice is to check the monitor in shop before you buy. bring test photos and software, spend a half day tuning and compare different models. it's such an objective opinion different ppl will say different things.

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Post by Longbow » Sat Aug 18, 2007 6:54 am

ok the huming sound of 931BW seems coming from the backlight

and the sounds is louder than my pc, no kidding, i can hear the sound from my sitting position midnight but not my pc (unless my aam off wd3200aaks is busy seeking)

i don't recall this sounds from my previous lcd screen, it's not too bad but it can be annoying to some.

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Post by hank » Sun Aug 19, 2007 9:52 am

Personally, thanks for the review "spot check" --- I'm buying for the first time since 1999, been reading LCD reviews for the past three days, and yours is the first and only review to remark on the power factor question, the first to point out that 'Energy Star' isn't helpful here, and the first to really address noise and dimming together.

I think a lot of reviews get written in noisy offices by older people with some hearing restriction. I want to know what a young person with good ears in a silent-PC setting hears!

When you do "spot checks" and other readers comment on what they know works, the result is great info. I think spurring discussion with a "spot check" and encouraging this kind of thread makes for more useful info than any other format.

I appreciate people bringing in pointers to thorough reviews elsewhere, and commenting on personal experience.

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Post by Longbow » Mon Aug 27, 2007 8:31 pm

Longbow wrote:ok the huming sound of 931BW seems coming from the backlight
the humming sound from the backlight or built-in power supply has became a struggling for me, it's very obvious in a very quiet room. it's noisier than my computer for sure.

anyone who bother to read this forum would find it annoying. all your effort on silence your computer could be destroyed by the monitor.

i'm not sure if this is an individual case but the review did mentioned the humming sound. if you buying any LCD monitor, it's better to check them in the shop, both the display quality, and any noise coming out of it...

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