| Author |
Message |
fragzero
Joined: 30 Aug 2012
Posts: 344
|
| Posted: Wed Jan 16, 2013 11:20 am Post subject: Cooling down 808 (convergence tray) |
|
|
So after taking a look at the entire BG808 cooling system i had some remarks. (pc modding experience)
- Only 1 intake fan - front convergence tray
All the mesh is horrible compared to current high flow mesh.
- The mesh on the front is restricting very restricting, coupled with a 80mm fan this can't be great.
- The mesh on the sides (which is the main intake)
- The back mesh isn't great but a huge surface so this is probably good enough.
Ideas i have
- Cut the mesh on the convergence tray - side intakes
- Add 2 fans to the side intakes
- Replace the convergence tray fan with a 92 or even 120mm fan
Why?
- Improve cooling in the convergence tray to reduce drift.
- I hope to improve the airflow which causes the stock fans to spin down and reduce the general noiselevel.
Anyone who has any experience with improving airflow in the 808 chassis? I can only seem to find ppl who changed fans (and never had a good result).
|
|
| Back to top |
|
 |
Ile
Joined: 09 Mar 2006
Posts: 1491
Location: Jyväskylä, Finland
|
| Posted: Thu Jan 17, 2013 2:52 pm Post subject: |
|
|
I modded my 808s so that convergence tray is sealed from rest of chassis (mobo air channel is blocked), so rest of chassis get only fresh air from side holes and between tubes. I added another hot air hole to bottom plate and make other bigger, now there is good holes under both convergence trays STK chips heat sinks. So hot air is blown outside straight from heatsinks.
There should be enough air from side holes and between tubes to feed back end fans. Extra input fans at sides might make it even louder, but who knows for sure without test.
I made lot of testing with my less noisy 801s (only two 120mm NMB), but came to conclusion that it cant be made silent enough without hushbox. So hushbox was only way for louder 808s, that had totally sealed air circulation from theater room. Same system will come to my new theater, if it ever get finished.
|
|
| Back to top |
|
|
AVphile
Joined: 02 Dec 2008
Posts: 334
Location: Ottawa, Ontario
|
| Posted: Mon Jan 21, 2013 10:51 pm Post subject: Re: Cooling down 808 (convergence tray) |
|
|
| fragzero wrote: | | - Replace the convergence tray fan with a 92 or even 120mm fan |
I looked into this and there isn't room for anything larger or even thicker inside (only outside) due to interference with the tray and chassis. Instead I would add a second 80mm fan at the front (right were the IRIS goes) to push more cool air into the side of the projector where the H & V scan boards are. I think 2 fans running a bit slower will make less noise than one, and hopefully that will reduce the image shift. Ile is your man - he told me these boards get hot and cause the rasters to shift. Do not push more cool air into the other side where the power supply is because the main temp sensor is on the SMPS and you want it to keep the main fans going at normal speed.
You can also slightly bias the cooling system however you want by strategically putting different value resistors (10-15 ohm) in series with SOME of the fans but slowing them all down will just cause the temp sensor to speed up the fans. I found that this doesn't really reduce the noise level of the main rear fans in the end, but can take the edge off that noisy front fan.
_________________
AVStefan
Old setup: HDFury3 -> BG-808s -> HD-145
New setup: JVC D-ILA -> Stewart StudioTek 130 G4
|
|
| Back to top |
|
|
stridsvognen
Guest
|
| Posted: Mon Jan 21, 2013 11:02 pm Post subject: Re: Cooling down 808 (convergence tray) |
|
|
| AVphile wrote: | | fragzero wrote: | | - Replace the convergence tray fan with a 92 or even 120mm fan |
I looked into this and there isn't room for anything larger or even thicker inside (only outside) due to interference with the tray and chassis. Instead I would add a second 80mm fan at the front (right were the IRIS goes) to push more cool air into the side of the projector where the H & V scan boards are. I think 2 fans running a bit slower will make less noise than one, and hopefully that will reduce the image shift. Ile is your man - he told me these boards get hot and cause the rasters to shift. Do not push more cool air into the other side where the power supply is because the main temp sensor is on the SMPS and you want it to keep the main fans going at normal speed.
You can also slightly bias the cooling system however you want by strategically putting different value resistors (10-15 ohm) in series with SOME of the fans but slowing them all down will just cause the temp sensor to speed up the fans. I found that this doesn't really reduce the noise level of the main rear fans in the end, but can take the edge off that noisy front fan. |
If you have 2 identical fans, try lower speed on one of them a bit.. like 5-10% so they dont produce the same frequency..
|
|
| Back to top |
|
|
|
|
