Thanks.

and regarding the brightness the Optoma Gt750 is 3500 lumens with native resolution of 720p, 300:1 contrast ratio and 3D feature..prices at 499 quids…

the brightness of Optama HD600X is 2600 with native resolution of 720p, with 350:1 contrast ratio and 3D ready (i.e. its needs an optama 3D adapter which costs 170quids to make it project 3D content) and the projector itself costs 350 quids..

the broghtness of optoma hd230x is 1600 lumens with 1080p with 400:1 contrast ratio and no 3d..it is priced at 499quids..

so which is the one to go for..??

also everywr the optoma gt750 is described as a gaming projector so wil the video quality be good if not better than optoma hd600x..?? or wil it be lower than the hd600x..??

I suggest you look more at brightness than resolution or 3d capability if you are going to be watching during daylight hours. Ambient brightness will affect picture quality more than any of these other parameters. Go for a high gain screen, because they tend to be directional and resist light from the sides to some extent. If there is a window behind where you will be watching, better put some really thick shades on it.

I don’t think 3D is that important. You may watch 2 movies a year on it. But it could be fun to occasionally play with, so get it if the cost difference is minimal.

Sorry for so many questions..Thank you..Cheers

I didn’t even think about deadening the front wall (I have floor standing fronts and on-wall rear and sides, you appear to have all in-wall speakers) and the back wall is actually almost entirely windows. I have it covered by thick blackout drapes, so hopefully they will have some deadening ability, since I really don’t have any place to put panels.

Now, off to do some more research!!

The acoustic panels were a bunch of work. I should write a post on it but no promises… Anyway, here are some things to consider.

The panels need to made of acoustic fiberglass to be effective. “Acoustic” ceiling tiles are too rigid, fiberglass insulation isn’t dense enough. If you don’t use the acoustic fiberglass panels, it won’t attenuate the proper frequencies. Typically, these panels are available in 2′x4′ panels that are about 3/4-inch thick.

To get the best acoustic performance, you’ll want about 60-70% of your walls and ceiling covered. You don’t want the room completely dead. You want some reflections scattered around the room. (Note that I didn’t cover the ceiling at all and covered about 80% of the walls – a few of the panels don’t have fiberglass in them. I thought panels on the ceiling would be ugly so I skipped it.)

You want the front of the room to be completely acoustically dead. I have 2 layers of fiberglass panels covering the entire front of the room and the front 3 feet of the side walls (beside the front speakers behind the speaker masks.

To get the best performance from the fiberglass panels, you want them to have a gap behind them between the fiberglass and the wall. 1/2- to 1-inch is ideal. This way, the sound that passes through the goes though the air gap behind the panel, hits the wall, reflects/disperses, and goes back toward the panel for more absorption. (Note that I didn’t do this; it was too much of a pain I’m not sure sure it adds that much of a benefit.)

The panels must be placed at “primary reflection points” for the 3 front speakers to get the best front sound stage imaging. (The surround speakers aren’t as big of a concern because reflection/dispersion is more desirable with them.) To find the primary reflection point: put your speakers in their desired location, sit in your primary seating position, have someone move a mirror along the wall. When you see the speaker reflecting in the mirror, that’s a primary reflection spot. You’ll want to do this for each of the front speakers. You will need to repeat this for both side walls. Ideally, you should do this for the ceiling as well (I didn’t, it’s a pain.) You may want to repeat this exercise for a few other seating positions as well.

You will need to install additional panels throughout the room. The location can largely be based on aesthetes. Just make sure you hit the primary reflection points. Having gaps between each panel will allow some dispersed reflection points around the room to brighten it up as little. (My panels turned out to completely cover the wall with no gaps in between, I liked that look, so I went with it.)

You will want extra fiberglass in each corner to act as a bass trap. Basically, put as much as you can in the corners. I put small panels at angles across the back corners and loose panels in the front corners behind the speaker masks. Bigger would be better in my rear corners, but would also start to look weird/ugly, so I didn’t pursue ultimate performance over visual appeal.

I made the frames out of 3/4-inch MDF. The frames are 2-inches wide. I joined the corners using a biscuit cutter, biscuits, and glue.

The frames are covered in fabric from Guilford of Maine. Their fabric is available in a wide variety of colors and textures. It’s thick and textured and hides imperfections and uneven surfaces well, and works well acoustically. I used a pneumatic stapler (and air compressor) to attach the fabric to the frames. It requires way too many staples to use a manual stapler. In general, electric staplers won’t hold up to the number of staples you’ll be putting though it. Electric will work fine for a few panels, but will likely die an early death. I read of someone going through 3 of them making panels. Pneumatic staplers are the way to go.

I attached the panels to the wall using industrial Velcro. I put about 6 2-inch long pieces on each panel. I didn’t trust the adhesive to hold the panels over time, so I put a couple of staples in each one (on the wall side and on the panel side both.)

Installing the panels was the single biggest sound improvement I had in my home theater, aside from adding subwoofers. The front wall alone made a dramatic improvement. It’s a lot of work, but it’s worth the effort.

I hope this helps – enjoy!