[adzan]

Folks,


My XG135LC has performed very well except for its sound noise. I'm looking to a way in improving its sound noise (meaning make it less audible). Building a hush box, as been done by several forum member, seem to be the solution, yet I'm looking to other way in doing so.


Am I correct to say that the noise mostly coming from its internall fans? Can the noise be reduced by changing the fans with a less audible fans? Are that kind of fans available? And any forum member try it before with positive result?


Regards,

adzan

 

[gordf]

Hello adzan, a while back Dan Ellis had tried a number of methods but the most successfu

involved connecting a one watt resistor or something like that in the fan connector. You

may want to search under his name. His additional heat was 5-9 degrees hotter, and I

am not sure I would do the probably warranty voiding change it if a hush box is doable...

 

[Iceman]

Adzan,


While the NEC XG series projectors definitely are some of the best CRT projectors around, optimizing air flow and noise probably was not the highest priority during the design process. It seems the fans were just thrown in at the finishing stages to keep the key components at a decent temperature.


My XG135LC measures 45-47 dB(A) at 1 m (spatial average), depending on room absorption. This is obviously waaay to high and I would not even consider a reduction of less than 10 dB. An almost noiseless projector would have a noise level somewhere around 25 dB(A) at 1 m, some 20 dB noise reduction in this case, making a hush box the only practical solution.


I believe the reduced fan current led to a noise reduction of 4-5 dB, clearly audible but not enough.

 

[adzan]

Guys,


Instead of lowering the current to the fan which will reduce its blade rotation thus lowering its noise, can we change the entire fan?


I think there are plenty of "silent" fan out there, any one try it before? Also, changing a fan will not be rocket science, correct?


regards,

adzan

 

[Iceman]

adzan,


The XG fans are relatively silent and changing the fans to the "no-noise" type will get you some improvement, but it will not be enough in my opinion (perhaps some 2-4 dB). For low noise performance, the XG series needs:

1. Optimized airflow to keep the air velocity as low as possible - turbulence induced noise is extremely sensitive to velocity.

2. "No-noise" type fans

3. Built-in silencers on air inlet and outlet

4. Vibration isolated fan mounts


From having studied the XG design, I would say it would be very difficult to incorporate these changes without a complete reconstruction of the entire chassis.


A correctly designed hush-box will get you a virtually noiseless projector with minimal hassle, so why complicate things?

 

[adzan]

Iceman,


Thanks for the input. I insisted not to build a hush box because

the NEC has a gorgeus design, its a pitty one have to hide it..


Anyhow, hush box perhaps the only viable solution, will do search for hush box design in the forum.


Thanks!

adzan

 

[Iceman]

Agreed, the XG series is quite good looking. Too bad NEC did not contract me for low noise design - I would have done it for a measly XG135LC .