CurtPalme.com Home Theater Forum

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

I'm amazed at how much quieter the barco is than my 1272. I'm going to be flipping it over and ceiling mounting it soon and want to know if anyone has tried reversing the flow on the fan on the big cover since it would be trying to blow hot air out the bottom. It seems to me that changing it to blow cool air in from the bottom would be more efficient, and I might add an exhaust system to send the hot air out of the room on our hot summer nights. It looks like all that is required is to flip the fan over on it's mount.

jantje112 · Joined: 17 Jul 2006 Posts: 328

The barco is quiet and the fans are temp controlled. I should leave it "as is"

My marquee sounds like a tractor compared to the 1209..

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

I'm thinking of swapping out the fans in my 1209s with some much quieter ones. Does anyone know how to adjust the voltage output on the fan power source? The fans I want to use need a little more voltage to start than the 7.5v that the supply provides. It looks to me like changing Z5 on the SMPS sub board would do it, but I'm not an EE and hope someone else has looked into this. Page 300 of the 1209 service manual.

zGman · Joined: 22 May 2006 Posts: 599

Please be advised to leave the 1209 fans and circuitry stock.
It is a very quiet and well designed system. You just got the PJ
a few weeks ago - why not get it hung and set-up and calibrated
before you frupp it all up with un-needed modifications.
G

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

I agree it is pretty quiet compared to the other projectors I have had. The fans in it were designed over ten years ago. There are much quieter fans available now, so why not use them? If I can improve the noise level in the room for the price of some fans and some spare time spent working on it, why not? Have others tried and fried their machines? If so, why not try to do it right? I'm still collecting stuff for the theater, better sound equipment, bigger screen, better seating, etc... it's a work in progress.

picree · Joined: 31 Mar 2006 Posts: 351 Location: Johnson City, TN

I checked into this once and was never able to find one that met all the voltage specifications (lower starting voltage, etc.) AND was truly quieter when comparing dB/CFM. Sure, some were quieter but they also moved less air. Even though they are ten years old I don't think there really are any better ones out there (if you really do find ones that are quieter please post model numbers here as others would be interested...although in a straight up comparison I don't think you'll find any).

I agree...leave it alone. It comes with too many complications. If the noise bugs you THAT much and you are in the early stages of theater design then put in a well ventilated hush box...plans can be found here and elsewhere...

zGman · Joined: 22 May 2006 Posts: 599

The important characteristic to consider about a fan is how it will work
with static pressure, or even harder to determine from specs, how it will
work in a Barco configuration where the fans must draw air through the
machine. Most fans I have tested completely fail at this, they just get noisy
when the inlet is restricted and fail to move air. The friendly folks at Barco
have built a lot of very reliable PJ's and they don't miss much, some care
should be exercised before second guessing their engineering. And the
fan specs you see now for so-called 'quiet' fans are most assuredly not
determined by engineering. Papst is the only one I have seen that has
graphs of static pressure vs cfm. And as I said, even that's not enough to
tell how it will work in real life.
Mr Kruger, you have a long ways to go to get your PJ setup and calibrated.
It is far more complex and far more capable than a 1271, so there's a lot to
learn. There's no point in trying to re-engineer a high quality machine
before you even get started working with it. Fiddling with the cooling
system can and will affect stability and component life. Reversing airflows
is a very bad idea, etc.....
G

n@t · Joined: 02 Apr 2006 Posts: 63

Hi,

Set 2 1A diodes in the line of fans.
That's all...

Bernd

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

Bernd,
The diode thing won't cut it in this application, the circuit will send more power to the fans to try to speed it up when it gets too warm. The diodes will defeat that function and that will be a problem. I want the circuit to function exactly as the factory intended it to with the exception of a higher start voltage. I believe the fans I want to try will have just as much cfm and pressure, yet still be quieter than the original ones. I would prefer not to enclose the pj in a hushbox, so this is an avenue that I want to explore. I appreciate the advice of the guys that say it isn't a good idea, but wonder if anyone here has ever tried this approach, and if so, could you link me to the thread that explains it? I have searched here and the other site with no results.

n@t · Joined: 02 Apr 2006 Posts: 63

Hi,

I have my 808s operated as 4 years, then the 1209s and now the 909.
Te PJ works perfect....
Where is the problem?

Bernd

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

Your 1209s worked fine with lowered voltages to the fans? Didn't the fan circuit have to work harder to make the fans spin fast enough to cool the sensor? Lowering the voltage to the fans makes no sense to me, as the fan control circuit is designed to speed the fans up when the temperature gets too high. I'm not interested in slowing down the fans or decreasing airflow at all. I want to raise the start voltage to the fans. That's all.

Ile · Posted: Mon May 19, 2008 8:03 am Post subject:

Zener or resistor works, I have tested it. Projector try to compensate little, but still voltage to fan will be lower. I believe this works because thermistor is in place that is not so sensitive to little lower air flow. Some hotter place would compensate this much better.

If Barco noise bother you as is, just little lower noise won't make you happy and there is still possibility to break something. If you measure or touch some hot boards like Hsift module heatsink you should find out why these need so much airflow.

You need hushbox.

Gerbrand · Joined: 13 May 2008 Posts: 199

I could have opened my own topic, but I think my questions fit in here... Smile

I am bothered by the noise of the fan that sits in the convergence tray of my BG808. So today I pulled out the tray, to see if there was any dust blocking it. There was... but just a little.

But I noticed something that puzzles me Question

WHY are the little vent holes in the base plate of the projector not located directly inline with the heat sinks of the convergence drivers? It now seems the air has to go through a narrow gap in order to get out that way.

I did a little testing and noticed there is indeed hardly any air flow coming out of the bottom vent holes. So why are they there at all? Does anybody know?

Cheers,

Gerbrand

benareeno · Joined: 22 Mar 2006 Posts: 1614 Location: ottawa, canada

for putting in the 2 1a diodes, do they just get spliced in on the power line to the fan(s)?

**kal** · Posted: Sun Dec 21, 2008 1:42 am Post subject:

Don't mess with Barco fans. They're heat/speed controlled. You'll get nowhere and only mess up the static pressure. Believe me, I've tried it all.

Want to quiet it down and cool it better? Use a hushbox with forced air evacuation like I do.

See: http://www.curtpalme.com/Hushbox1.shtm

Kal

benareeno · Joined: 22 Mar 2006 Posts: 1614 Location: ottawa, canada

Ile said above that he put the diode on several of his projectors with no ill results...I was thinking of just taming the middle fan a bit as it seems to be the worst offender. I fully intend to hushbox it as well, and I figure that if and when I do, the diode could be removed. Or, the diode could stay and the projector would be that much quieter when hushboxed.

I remember hushboxing my PGXtra, and the noise seemed to be greater when I boxed it in!

The Barco is already quiet...and when I lift the top it's even quieter. But if I add a hushbox, I think a) it could survive just fine with the middle fan running a tad slower and b) it would make the hushbox even more effective because of it.

My basement is always cold too...even in the summer it's quite cool down there. But then again, I'd rarely watch a movie in the summer. It's a winter hobby Smile

Ben

Gary M. · Guest

I don't understand how the Barco fans are heat sensor controlled, they only have the - and + leads to each fan, no third wire?

-Gary

benareeno · Joined: 22 Mar 2006 Posts: 1614 Location: ottawa, canada

There must be some sort of thermoresistor which allows more current to the fans when the chassis reaches a certain temp.

**kal** · Posted: Sun Dec 21, 2008 4:41 am Post subject:

There's a thermistor (temp controlled variable resistor) right up near a heat sink the power supply. It's used to control the voltage to the other fans from 7-15V (give or take).

Kal

Gary M. · Guest

thats great so now we can replace fans if needed and not have to worry about problems

I had to replace the fans on my 1209s, they were filled with mold, the originals were impossible to locate and I didn't want to buy used ones

I used Scythe KAZE-JYUNI SY1225SL12H which match the internal fans specs as close as possible, PJ is a pinch quieter afterwards

I wouldn't waste time trying to quieten the 1209s, it is barely audible thanks to the large 120mm fans, I replaced for other reasons

adding resistors and slowing fans is NEVER the answer, with newer fans you can increase CFM and lower noise albeit slightly Thumbs Up

-Gary