I am looking at getting a Sharp DT-510 as a first projector. Cant find one to demo where I am, but it is listed as 29db in eco mode. However I see that some DLP units like the BenQ W5000 and some InFocus units go as low as 25db.

Is 29db considered loud/obstrusive? I dont have major needs, so this unit would be good as it is relatively cheap for what it is, but wold like to know if the sound will be annoying....

I had the HD70, which was 28dbl I think. I didn't find that to be an issue at all.

"Obtrusive" noise is so subjective. You might want to go to a site like http://www.projectorcentral.com/, find reviews of projectors that are rated at 29dB and see what the reviewer has to say about the kind of noise that produces.

It's probably not going to be that big a deal. I've got a Panasonic AE900U that is rated at 25dB in Eco-Mode, it sits on an open shelf about 5 feet in the 2 o'clock position above and to the side of my right ear and I can barely hear anything as long as there is something on the sound track.

Picture will be amazing - the sound is a little louder than what I would consider quiet enough that it should not be considered. When the film is going you don’t hear it.

The blacks are way worth the slightly louder fan.

Picture will be amazing - the sound is a little louder than what I would consider quiet enough that it should not be considered. When the film is going you don’t hear it.

The blacks are way worth the slightly louder fan.
Thanks for the input. If you dont hear it when "film is playing" then are you saying it is annoying when you not actively focused?

I am basically weiighing getting this unit (ie staying low cost and affordable with 720p, but noise rated 29/33db) or stretching myself a lot to get the BenQ W5000 (1080p, not questions at all about noise at a rated 25/28db). Both seem to be possibly the best values in 720P and 1080P DLP categories.

I am going to have a screen of 84"-96", depening on the particular porjector, so I am willing to pass up the 1080p, but annoying noise leves, would NOT be okay. So if I cant get the image performance and noise levels I need in the sharp then I will prefer to just buy the Ben Q and be done with it. But if the DT-510 is quet enough and I dont NEED to spend the money, then Id rather hold on to the extra $1500 and invest it or something...

I feel your frustration. I do not find it annoying when I am not actively focussed but if I know or think enough to listen for it in quiet scenes I can hear it. It is one of those things that now you know about it - it may bother you. It depends on you. My best recommendation is to try to listen to a projector with this db rating. I have had many many people to my HT and no one has ever said or noticed anything. We are pretty hyper sensitive to these types of things around here.

It is similar to when you are in a public cinema at the beginning of a film. If you listen for the projector through the “window” in the back rear of the theater you can hear it. When the movie comes on it (the sound) disappears.

I have an AX200 and on normal it is about as loud as when the central air is on. So if that doesn't bother you then the PJ won't either. I don't think the Panasonic is any better than others.

I think it all depends on your placement of the projector...If it's directly behind you then you will probably hear it - If it's hanging from your ceiling on a mount then maybe it will automatically switch to a higher fan setting and you will hear it.

I know my Panasonic AE700 switches to a higher fan setting when you set it that way. ( I don't ceiling mount mine because it would be too noisy for my liking ) I have mine behind me and in the winter in eco mode i don't hear it much but it needs set to high fan mode in the summer and i do hear it ( it's annoying too )

Take into account there are lots of movies which have very quiet scenes in them and ask yourself if hearing some fan noise will bother you during those scenes.

Based on the size of my room and the specs fo this projector it would have to be ceiling mounted on the wall above/behind the sofa, which would be the main viewing position. I do have an outsdide air vent in the side wall about a metre and a half away from where the projector would be, so that is a mitigating factor.

From what I am hearing, this sounds like the noise level of the Dt-510 would be anything from a mild issue to a minor annoyance, depending on good fortune. BUt this projector is not just for movie time - it will be the the main TV watching unit in the house as well.

I'll have to think about this one......

FYI - A 29dB fan is twice as loud as a 26dB one, Perceived loudness doubles every 3dB. A typical household room has a background noise level of around 20dB, unless a lot of extra effort is made to quiet it. A PJ with a 22dB to 24dB fan is, usually, considered to be quiet.

A lot depends on how objectionable the fan noise is. If it has a lot of higher frequencies (over 1 KHz), then it is worse than if most of the noise is in the lower frequency range.

For reference, a typical desktop PC (with an Aluminum case) is around 32dB to 35dB, unless it is designed and built to be very quiet (even water cooled ones are around 24dB to 27dB).

FYI - A 29dB fan is twice as loud as a 26dB one, Perceived loudness doubles every 3dB.
Hi Claus - not true, a common misperception. It takes twice the amp power to cause a 3db increase (the reason for the misperception), but that is only perceived as slightly louder. A 10db increase in sound levels is generally perceived as double the loudness. Lots of supporting references out there, here's just a few:
http://www.enjoythemusic.com/magazine/manufacture/0907/
http://www.superlux.us/frequency_response.html