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Very interesting.

How wonder how that works.

Possibilities are

- Adding the 2nd iris catches stray light that doesn't add significantly to brightness but does add significantly to CR, since the amount of light contributing to the black floor is many orders of magnitude less

- JVC grades the panels and picks better ones for the upper models

- Something related to however they got 100 L more (which is itself a head-scratcher)
I wouldn’t be surprised if a lot of the effect is the effect on stray light - the iris places a narrow window in the light path so theoretically less oblique light rays that would bounce off the side of the light path would be allowed to pass. Could also be partly due to some added efficiency by the updated 3rd polarizer mentioned above ifIt’s more efficient and can reject more of this stray light - would make a lot of sense if they placed this on the green channel since it’s by far the highest intensity. May also mean that the improvement in adding the iris could be more pronounced if scatter is reduced to a less effective light path.. if you look at my last picture in the linked thread you can also see that there is a lot of light leakage out of the light path and into the chassis so it’s not as sealed/efficient as you’d think..
 

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I wouldn’t be surprised if a lot of the effect is the effect on stray light - the iris places a narrow window in the light path so theoretically less oblique light rays that would bounce off the side of the light path would be allowed to pass. Could also be partly due to some added efficiency by the updated 3rd polarizer mentioned above ifIt’s more efficient and can reject more of this stray light - would make a lot of sense if they placed this on the green channel since it’s by far the highest intensity. May also mean that the improvement in adding the iris could be more pronounced if scatter is reduced to a less effective light path.. if you look at my last picture in the linked thread you can also see that there is a lot of light leakage out of the light path and into the chassis so it’s not as sealed/efficient as you’d think..
More to this point - I had found a diagram of the light path in DILAs in I believe the RS46 thread. The area where the second iris is placed is in a compartment directly before a pair of lenses and just before the light gets split into blue and green as you can see in the last picture I posted in the other thread. If you look at the diagram, these would be the integrator and condenser lenses before the color splitting filters in the diagram. Reading up on it, sounds like integrator lenses are designed to take light rays and create perpendicular light columns to go directly to the condenser lens. I wonder if a big part of the puzzle is that the iris prevents a lot of the light that would end up going around the edges of the integrator from being passed along the chain and thus isn’t processed properly by the downstream lenses etc.
 

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Hello fellow X570R owners. I am having a bit of an issue with my unit and was hoping to possibly gain a bit more insight or see if others have also had a similar issue that they have resolved. I have searched this thread and have not seen anything like this mentioned before.

All of a sudden my projector is making a very audible buzzing/creaking type of noise.

I first noticed the sound while I was watching some HDR content and it was quite loud. So I turned the projector off and then powered it back on. Upon restarting the sound was again present and very loud and the screen had a strong green tint to it. I could still see the nvidia shield menu through the green, but it was quite green. I then powered down again, unplugged the power cable after waiting for the lamp to cool down and waited a few more minutes after then. I then restarted and have watched several things since then and have not encountered the green tint issue anymore, but the sound is still present. It seems to be a little less audible than those first two times I heard it, but it’s still obvious and abnormal. I have cleaned the filter and gently vacuumed the grills as well with no change. I also left the unit unplugged overnight and it is still present when plugging back in and powering up. It begins as a creaking type of noise upon powering up and then turns into a constant buzzing afterwards

With the help of forum member Dominic Chan (who calibrated the unit and did a fantastic job, by the way) we believed the issue to be coming from the 4K eshift mechanism, as when I turn the 4k eshift off from the MPC level menu when watching 1080P content, the buzzing completely disappears and will only start up again after I switch it back on. There is no change in the noise level of this buzzing between high and low lamp modes either when 4k eshift is on.

The picture itself also appears fine and unchanged. I have not noticed any change in sharpness, brightness or quality from what I can tell since the buzzing began. The projector is ceiling mounted and has plenty of space for ventilation - it is also a completely open theatre room and is not housed in a cabinet of any kind

Lamp hours is currently around 500h on the original JVC lamp and there is no indication or warning light on the panel itself whatsoever.

Aside from the calibration, I have not made changes to the settings except for the occasional change in brightness, lens aperture and lamp power as needed based on the source material/viewing preference

Also, I have noticed now that after watching content for approximately 2-3 hours, the buzzing noise lowers in volume but is still present. Almost like it needs to be "warmed up" before the sound is less. When first using it, the sound is very distracting, after that 2-3 hour period it is at least tolerable, but still audible.

I took the unit in to a certified JVC repair centre here in Canada. Diagnosis came back that it was a coil vibrating inside the actual optical unit. I was told that the coil by itself could not be replaced in isolation and that the entire unit would need to be replaced and even the repair centre said it was not worth the cost (upwards of $2,000).

Has anyone ever encountered this? Is there any solution that may make the noise more tolerable in any way?

Thanks in advance for the help!
 

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Perhaps potting compound or dripping hot-melt glue over the offending coil would take care of it, or at least quiet it down.
Thanks for the reply. Is that something the average person can do? Or would I need to take it back to the repair centre? Is there a reason the repair shop did not recommend this as an option? Or is this not a JVC-approved remedy and that is why? lol
 

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Is that something the average person can do?
Beats me, dunno what's involved in getting to the coil.


Is there a reason the repair shop did not recommend this as an option?
Lack of imagination and/or unwillingness to take any risk doing a non-sanctioned repair.

Though if they had thought of it they could have asked you to sign a waiver.

Or it could be that a nearby sensitive component prevents it.


Or is this not a JVC-approved remedy and that is why?
I highly doubt it.

You could ask JVC if they can think of a risk associated with the fix, and of course they'll say do so at your own risk.
 

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Beats me, dunno what's involved in getting to the coil.




Lack of imagination and/or unwillingness to take any risk doing a non-sanctioned repair.

Though if they had thought of it they could have asked you to sign a waiver.

Or it could be that a nearby sensitive component prevents it.




I highly doubt it.

You could ask JVC if they can think of a risk associated with the fix, and of course they'll say do so at your own risk.
Yeah, I am pretty sure the risk vs. reward was not worth it for the repair shop considering the projector is in perfect working order aside from the buzzing with low hours. It is definitely something I can live with, but was hoping for an easier and more risk-free solution lol
 

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Thanks for the reply. Is that something the average person can do? Or would I need to take it back to the repair centre? Is there a reason the repair shop did not recommend this as an option? Or is this not a JVC-approved remedy and that is why? lol
JVC (Canada, at least) consider the optical block to be one “black box” and do not recommend doing anything inside the block, not even cleaning it.
 

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JVC (Canada, at least) consider the optical block to be one “black box” and do not recommend doing anything inside the block, not even cleaning it.
Thanks for chiming in, Dominic. Yeah, I figured as much. I used the projector earlier today and it was only making the lesser audible sound so hopefully this is a good sign and maybe it will settle into that or possibly self correct somehow depending on the vibration and position over time.
 

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I tried a 48GB cable from Amazon. Then upgraded the firmware on the Denon. It seems a bit better, but has an occasional glitch. Much shorter. Only for less than a second. With the picture freezing too.

It is only when I play ATMOS from 4k discs. Blu_Rays with ATMOS are fine. So its got to be the bandwidth. I’m running 7.1.4. I suspect not many people do that.

I’m thinking it might be the player too. I have a cheap Sony 4k player. What are people running for a 4k player?


I have had good luck with the certified high speed mono price cables.
From my receiver to projector I use a ruipro 40 ft. no issues
 

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I tried a 48GB cable from Amazon. Then upgraded the firmware on the Denon. It seems a bit better, but has an occasional glitch. Much shorter. Only for less than a second. With the picture freezing too.

It is only when I play ATMOS from 4k discs. Blu_Rays with ATMOS are fine. So its got to be the bandwidth. I’m running 7.1.4. I suspect not many people do that.

I’m thinking it might be the player too. I have a cheap Sony 4k player. What are people running for a 4k player?
My 4K discs are ripped to a hard drive and I played back lossless via Plex. Never had any issues. Nor did I have issues when playing 4K discs via Xbox One s.

My cable is at 12 m ruipro optical.

Maybe it's your player. It should be set to output 24p. 4K at 24p even with atmos, which is just metadata, doesn't come close to the 18 Gbps upper limit in the HDMI 2.0b spec.

-T
 

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I'll check that. It didn't happen with 7.1.

Did you find a way to rip so you still get the Dolby True HD audio? I run Plex too.

My 4K discs are ripped to a hard drive and I played back lossless via Plex. Never had any issues. Nor did I have issues when playing 4K discs via Xbox One s.

My cable is at 12 m really pro optical.

Maybe it's your player. It should be set to output 24p. 4K at 24p even with atmos, which is just metadata, doesn't come close to the 18 Gbps upper limit in the HDMI 2.0b spec.
 

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I'll check that. It didn't happen with 7.1.

Did you find a way to rip so you still get the Dolby True HD audio? I run Plex too.
I have a UHD friendly drive and I updated the firmware to allow me to read 4K UHD media that I own.

I use makeMKV and rip just the main movie. When you use makemkv, read the tutorials first if you do not know how to use it, the tool allows you to select the lossless audio and you can even select the lossy audio too. And this way you'll have both and then you can switch between the two using your Plex client.

I only rip the lossless because I don't want lossy.

Also, I was looking at the bit rate required for 4K 24p 4:2:2 12 bit color... The bit rate requirement is very low. Is somewhere less than 10.2 Gbps. You'll need close to 18 gigabits per second when doing 4K 60p 12-bit color 4:2:2.

that's a lot of words for me saying I don't think it's a bit rate problem. You probably have a problem in your player or your projector.

-T
 

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I tried my old Panasonic player. It works fine. I'd leave that one in the basement, except it is terribly awkward to use. Is there anything to check on the Sony? Otherwise, I guess another player.

Just for the record, the Sony was fine until I go up to ATMOS. It was a new receiver at that time too.


I have a UHD friendly drive and I updated the firmware to allow me to read 4K UHD media that I own.

I use makeMKV and rip just the main movie. When you use makemkv, read the tutorials first if you do not know how to use it, the tool allows you to select the lossless audio and you can even select the lossy audio too. And this way you'll have both and then you can switch between the two using your Plex client.

I only rip the lossless because I don't want lossy.

Also, I was looking at the bit rate required for 4K 24p 4:2:2 12 bit color... The bit rate requirement is very low. Is somewhere less than 10.2 Gbps. You'll need close to 18 gigabits per second when doing 4K 60p 12-bit color 4:2:2.

that's a lot of words for me saying I don't think it's a bit rate problem. You probably have a problem in your player or your projector.

-T
 
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