Blaser HT build Thread

**Blaser** · **01-12-08, 06:26 AM**

Well,

After successfully building my RL-P18 LLT subs, I got a big sound in my small 2000 cu ft room. I am now willing to upgrade my viewing experience as well.

I have chosen the route of front projection via a white screen. To do this I will have to build a false wall to hide the LLTs and bring the screen in front of them.

I also want to add some room treatment to have a more articulate sound as I am feeling some harshness around 1-2 KHz.

This thread will seriously begin in next post and hopefully with more details on my build plan as well as photos.

This should be tonight or so.... I think this will be lots of fun

**Blaser** · **01-12-08, 06:27 AM**

The Basics:

My room is 5 m*3.8m*2.7m (16.4 ft*12.5ft*8.85ft) That is about 1800 cuft. Listening position is about 2 ft from the backwall (Bryan might not agree with that

) and watching is along the room axial dimension. Room has brickwalls and a carpeted wood floor.

My subs are around 650 L each (22 cu ft) and are located along the Front wall. Being about 1 m (3ft+) high it is not appropriate to place a screen on the wall behind them. and thus I chose the more elegante route of a false wall to have the height of the screen I want, speakers close to screen and above all a nice looking theater.

One thing important to note is that my subs are about 70 cm wide, and the false wall will be around 80-90 cm from the room front wall.

This reduces the viewing distance to be around 3.4 m (11.15 ft).

Here are some photos: (the TV and rack will be removed upon starting building the false wall)

Projector and screen

I had a deal with Epson Egypt to have the new EMP-TW2000 for 3480 USD. That is an excellent deal as the Mits for ex are sold way more expensive here (HC 6000 is 6000+ USD). This is a 1080p projector and is sold in the US as the Powerlite Cinema 1080 UB for about 4000 USD (but it has an extra buld and a stand are added to the package). As statde It has 50K CR with Iris.

Regarding the screen I chose the Carada Ctriterion 102" BW screen. This makes about 36.8 angle degrees.
Although I am not an expert and this will be my first FP system, I will post a review of them (as best as I can) exclusively to HTS when they are available

In the photos you can see the front stage, a sub and rear of my CRT (where the false wall will be built) as well as the couch and rear speakers between which the projector will be located. To do that I will have to install a DVD rack/bookshelf just below the speakers and just above the couch. The projector will be above the rack. Expected dimensions is roughly 2 ft tall and 4 ft wide.

My next post will address construction details and acoustics...so hold on!!

**Blaser** · **01-12-08, 06:29 AM**

False wall:

Right in front of the subs will be built the false wall to support the 102" screen. I will just do something simple like everybody. There will be a wood frame for the screen and for the fabric around. I will use a black tissue that it is quite porus as a fabric. This will indeed hide the subs and the (ugly) window a/c.

I will have to build a (screen) wide equipment rack to house the center and equipments. It be place right below and in front of the screen.

Regarding the fronts, wife believe seeing them is better than hiding them (she likes their look). I believe the contrary but hiding them behind the fabric requires additional wood work so that the frame will have a Z shape to house the fronts.

I have not decided if I should follow the wife or not, but it seems quite easier that way and it will also allow me to move the speakers (will I need to do it??...I think not).
I am not sure how wide and thick should the wood frame be I was thinking 4" * 1" polywood.

New DVD rack used as a projector stand:

The DVDs I used to store above the subs will have to find somewhere else and so I thought of building a wide rack (something very simple like a bookshelf) and so it will also bear the projector. Through distance should be around 12'.

Room Colours:

You can see the colours in the photos. The sidewall are yellow and ceiling is white. With a 102" screen I don't know if the PQ will be affected by the white ceiling ...I was thinking of changing the colour to brown...but I might wait to see if I really need to do that.

Acoustics:

With my CRT the fronts were quite far from the side wall (3 ft+), and while my room is not treated the sound was not overly bright or so. I moved the fronts back against to the subs and closer to the sidewall (1.2 ft) to similate the sound as if the screen was there and I noted some unclarity in the sound and propably some harshness in the 1-2kHz range. this specially shows up when I listen to loud music (and I do that often).

I guess that this is due mainly to early reflections from the sidewall and propable the subs as well.
I have also visited a showroom with calibrated acoustics (as I was told) and it seems much more dead and quite (I liked that).

I do not want my HT to be perfect but at least I need to have a decent sound.

I have read quite a lot about that and it seems that I need to treat at least the subwoofers side (that is just behind the screen) as well as the early reflection points (I guess will be 2 feet * 4 feet after the subs)

Here is a picture of a material that is available here and that I used in the insulation of the subs (see photo). While I don't know the name in English I describe it as a spongy material (it really feels like a sponge to the touch)... and I believe it is an absorbtion material.

I am planing to use 2" think for the sidewalls and 1" thick for the subs.

Here are some questions:

- While there was never an agreement between the big names of this industry on whether the front wall (behind the subs) should be insulated or not, I do not know if it should be insulated.

- Should I add some insulation on the rear wall (below the upcoming rack/bookshelf)?

- should I add add some insulation somewhere els along the sidewalls below the wall carpets? (see photos)

Suggestions will be highly appreciated.

**Ilkka** · **01-12-08, 06:46 AM**

Can't wait!

**bpape** · **01-12-08, 08:32 AM**

Bring it on. Let's get the rest of the room up to the sub's level.

Bryan

**Sonnie** · **01-12-08, 08:34 AM**

Yep... looking forward to your progress reports.

**Blaser** · **01-12-08, 02:14 PM**

Ilkka, Bryan and Sonnie,

Thank you for these words of encouragement

....I am now editing my posts.

**Blaser** · **01-12-08, 04:15 PM**

Even my 1.2 year old daughter can't wait for a big screen

**Prof.** · **01-12-08, 10:18 PM**

Quote:

blaser wrote:

Room Colours:

You can see the colours in the photos. The sidewall are yellow and ceiling is white. With a 102" screen I don't know if the PQ will be affected by the white ceiling ...I was thinking of changing the colour to brown...but I might wait to see if I really need to do that.

Ideally the ceiling and walls should be a darker colour..and yes, the white ceiling will reflect light from the projector..

Quote:

blaser wrote:

While there was never an agreement between the big names of this industry on whether the front wall (behind the subs) should be insulated or not, I do not know if it should be insulated.

If you're building a screenwall, then it's best to cover the front wall behind it with at least 1" thick insulation..If not the whole wall, then at least behind the screen

Quote:

blaser wrote:

- Should I add some insulation on the rear wall (below the upcoming rack/bookshelf)?

Wouldn't hurt..

**bpape** · **01-12-08, 10:43 PM**

If that's going to be approx the final setup, then you'll need some absorbtion directly beside the speakers for reflections and also on the face of the sub as it's acting like a wall in terms of SBIR and muddying things up.

Bryan

**Blaser** · **01-13-08, 08:43 AM**

Can anybody recognize the insulation material above? What thickness to use?

**Blaser** · **01-13-08, 08:48 AM**

There is another thing I would like to ask about: that's the HDMI cable.
When I bought my Samsung 870 (720p DVD player), it came with 3ft free HDMI cable. Supposing I place the DVD near the projector, will any cable work with the 1.3 version of the projector? Or does it need a special 1.3 cable?

Thank you!

**Blaser** · **01-13-08, 04:30 PM**

I really don't know why...but when I imagine the screen dimensions, I feel I need something bigger than 102" (viewing distance is about 11.15 ft). I am leening more towards a 106" screen, but the viewing angle might exceed 40 degrees

...This is making me wait before I order the screen, really can't decide

From the other side, the fronts will have to go even closer to the walls, and as I have no experience with room treatment, I also do not know if the sound can be OK with absorbtion

**Ilkka** · **01-13-08, 05:13 PM**

I wouldn't go ANY larger than 102". There's only one thing that can ruin up the 'big screen' experience - too large screen!

Especially when you are coming from a 28" 4:3 TV...

**Blaser** · **01-13-08, 05:33 PM**

Many people say that in the first month or so, the big picture is amazing, but most of them wish they had a bigger one shortly after.
Ihave reconsidered my room width and I see a 106" would be only about 2" wider and it fits quite well, and it would have a more imposing appearance.

Anyway, I could still zoom back to 60" if I wanted with a 106 screen

.

I also carefully rechecked for the viewing angle and I obtained about 38 degrees...It is still not that far from THX.

**Ilkka** · **01-13-08, 05:35 PM**

Quote:

blaser wrote:

Anyway, I could still zoom back to 60" if I wanted with a 106 screen

.

Umm, you can't really do it so easily. You don't want to be looking at that white area outside the active image.

**Blaser** · **01-13-08, 05:37 PM**

Well...With the lights out and 102" the white area won't be too much noticeable then

Just concentrate on the movie man

No really, according to what I have read, many regret not to have bought the biggest screen they could fit in the room regardless of viewing distance! Prof where are you??

**Blaser** · **01-13-08, 05:51 PM**

Quote:

Prof. wrote:

If you're building a screenwall, then it's best to cover the front wall behind it with at least 1" thick insulation..If not the whole wall, then at least behind the screen

Actually since the screen is reflective,my guess was quite the opposite. I thought I should insulate all but behind the screen...Am Imissing something?

**Rodny Alvarez** · **01-13-08, 11:31 PM**

I have a 100" screen and I'm sitting at 13ft from it and that's plenty, I would not go any bigger than 102 at that distance!

When you sit to close to the screen its like sitting in the front row of a Tennis game

**Blaser** · **01-14-08, 03:32 PM**

OK Rodny!

But I believe many other will post things like a more envelopping and cinematic experience, and that they wished their projector could have a larger zooming option for a bigger screen... Let's just wait for them.
BTW, 106 diag at 11.15' is only 1.45 times the screen width and not that far from 1.5. And If I just go back a bit less than one feet, it gets me over 1.5 screen width

I am still waiting for Prof and others to shime in

**wbassett** · **01-14-08, 05:10 PM**

I sit around 14' back and we have a 106" screen. Many people go as large as they can at first for that initial wow factor, but find out backing the screen size off some gives a brighter, sharper image but still doesn't take away from the movie theater 'big screen' feeling.

For my room setup and tastes I wouldn't want anything smaller than 100" and no larger than the 106" that I have up currently. If I had to go smaller than that I most likely would have gone with the Mits 73" HDTV at that point. That's my personal preference though.

There is a formula for screen size to seating distance, but I find a lot of people don't follow that to a T and it ends up being what your personal tastes are, but I do agree with not going too big. Nobody likes sitting in the front row at the movies.

**muzz** · **01-14-08, 05:30 PM**

I have 115" screen, and my seating area is about 11'......

Minty.

Only 1 person ever said that it was too big (nope, not going there)...
She also has a bad eye, so she's really looking at it with 1 eye, so I guess it would be a bit tougher to see the whole screen.

Everyone else that has seen it, just loves it...my brother and nephew sure loved watching the Patriots(in HD) on it the other night, and are coming over again this Sunday to watch them again.

I would think 106 would be fine.

Have Fun Ahmed,

m

**Prof.** · **01-14-08, 05:56 PM**

Sorry for taking so long to get back to you...I've had satellite server problems

If you have too large a screen, or you sit too close with a 16:9 AR screen, you will find that your eyes are constantly moving up a down and from side to side, to take in the whole image which becomes very tiring..

Given your situation, I would think that a 106" screen would be suitable , but certainly not any bigger..
I can go wider and sit closer to my screen because I use a 2.37:1 AR Scope screen..

The reflective qualities of the screen material has no bearing on the acoustic treatment that's required.
Placing acoustic material on the front wall (preferably right across the wall) will help to absorb back reflections and standing waves behind the screen and speakers, when using a screenwall..

**Mike P.** · **01-14-08, 06:20 PM**

Quote:

blaser wrote:

There is another thing I would like to ask about: that's the HDMI cable.
When I bought my Samsung 870 (720p DVD player), it came with 3ft free HDMI cable. Supposing I place the DVD near the projector, will any cable work with the 1.3 version of the projector? Or does it need a special 1.3 cable?

Thank you!

The Samsung 870 is not 1.3 capable so any regular HDMI cable will work with your projector.

**bpape** · **01-14-08, 06:55 PM**

Just remember that when designing and laying out a room, seating position is established first. Everything else revolves around that. Closer seating allows a smaller screen to give the same enveloping experience - and also allows better, smoother bottom end response and better surround stage.

Once seating is established, then we can look at proper screen size, where that pushes the speaker locations, and what kind of PJ it will take to fill that screen in terms of both image size and brightness. It all needs to be considered together or you'll constantly be fighting one thing or another.

Bryan

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