The Zinema construction has started!

Once upon a time.....
I was very interested in HT since the first Dolby ProLogic amplifiers came on the market and enabled private people to have the surround experience in their homes! My amplifier was one of the first ProLogic Yamaha devices available in Europe and I watched movies on my small TV set fed from a VHS player with a crappy and cheap 3/2 speaker setup, but I was impressed!

At the time when the first DVD's came available in Europe (around 1999) I upgraded my sound system and bought the best gear I could get for my budget these days - Sony DVP-S7700 DVD player, Yamaha DSP-A1 amplifier and Magnat Vintage 7 Series speakers for a decent 5.1 DD/DTS setup...WOW what a difference!

About the same time I always wanted to add a video projector to my system, but I could never afford to pay these crazy prices the charged back then - so I decided to build my own LCD projector. After more than 2 years of design and development I finally had this unit working with a quality I could enjoy watching movies with it.

So in 2001 my first complete HT was installed in my living room with a DIY 250cm (98) diagonal screen, self developed VGA 3 panel LCD projector, HT-PC running dTV (now called DScaler) and my Yamaha / Magnat audio setup.

In 2002 we planned and built our own house and of course a dedicated HT in the basement was part of it. In September 2002 we moved in, but there was of course no time or money left for the cinema - so it ended up as a storage room. Although I installed my audio system in our new living room, the projector and screen was kept stored in the basement.

In December 2002 the second part of LOTR came to the cinemas and I planned to invite some friends at my house to watch the first part before going to see the second in cinema. Well, the sound was good enough in my living room, but watching LOTR on a 70cm (27) TV set sitting 4m (157) away from it? NO WAY!

So I grabbed my screen and installed it temporary above my TV in the living room, but there was another problem - my self-made projector was fine, but without a hush box way to loud, only VGA and just for this evening a did not want to install it together with my hush box to the ceiling of my living room..but my wife had the solution.she bought me a used Sony VPL-PX 20 projector for Christmas and it arrived just in time 2 days before my planned LOTR session with my friends - saved!

Now guess what.the temporary solution in my living room is still in place, and we have enjoyed it during the past 4 years.
In the meanwhile I have colour corrected and contrast optimized the Sony projector (and it rocks now!), upgraded the HT-PC with new hardware and software, collected and watched over 500 DVD's and had many good ideas for my dedicated HT.


Enough from old stories and let's jump to the Zinema!

As I already mentioned the cinema is located in the basement of our house. The room is 4,5m (177) wide, 4,88m (192) long and 2,32m (91) high - with an extra equipment room in the back. The walls are 30cm (12) thick and made of solid concrete. Also the ceiling and floor is solid concrete. There is no window in there and 2 doors to enter the cinema (plans will follow later). Some might say the dimensions of the room are not ideal, but this was the maximum size I could do and I believe it will be just fine!
As you can image my problem is not to keep the sound inside the room, but to reduce the reflections and reverb time.

For the screen I decided to go for a 2.37:1 constant height setup where the screen is 332 cm (130) wide and 140 cm (55) high with vertical masking for smaller AR.
And YES - I like it LARGE!

There will be 2 rows of seats, the last row on a 30 cm (12) riser providing enough space for 6 people to sit comfortable. The 7.1 speaker setup will be placed behind framed walls - so not a single speaker will be visible. Carpet floor, soffit around the ceiling corners with lights installed. Acoustic treatment on the walls and everything covered with fabric.

Almost everything in this project will be DIY - here is a short list of planned things I will build:

• 332cm x 140cm (maybe curved) screen with electric vertical masking

• 2 main, 1 centre, 2 side surround and 2 back surround speakers, all 7 full range speakers using the same VISATON chassis for optimal sound match

• 1 sub built as transmission line to produce subsonic bass down to 17 Hz for LFE

• Bass traps to handle the low bass problems in this room

• Anamorphic lens for a VC of 33% - prism based

• HT-PC with display and input control built in a small table in front of the first row of seats - for the DVD playback and room control

In the first phase I will use the Yamaha DSP-A1 and only a 5.1 setup together with my Sony VPL-PX 20. Later I will upgrade to a Pre-Amplifier + four 2-channel amps and a native 16:9 projector but this would blow my budget right now.

The planning of the room is done, the speakers are designed and computer simulated for optimal performance. The room acoustics are also simulated including the planned sound treatment but since computer simulations are never 100% accurate I will have to test it during the construction to check if I am going in the right direction - but it will be a good starting point.

Tomorrow I will post some of the acoustic simulation results and some very primitive 3D renders (coming from the sound simulation) of the room - so you will get a better impression how it will look like.

I hope to get some feedback of the community here since I am following this forum now for some years and I have to say this site is the best source of information I have found so far!

Let the construction begin

As promised - here are some design pictures....

This is a top view coming from my acoustic simulation software - it's not a real room design, it includes only important information for the sound simulation.



The front wall be covered bottom to top with 5cm (2") acoustic mat. In the 2 front corners a I will construct bass absorbers using 10cm (4") rigid fibreglass panels.
The soffit is made of a wooden frame and 8mm particle board on it - then covered with fabric.

The ceiling will be covered also with 8mm particle boards, spaced 2cm from the concrete ceiling and the air gab filled with insulation.

On the floor I will use carpet and also on the riser in the back of the room.

For the simulation I did not put any absorbing material on the back and side walls yet - only frame the walls and cover it with fabric. This gives me nice reverb times - but is this true?
When I cover the side and back wall up to the ear position with 5cm acoustic material I will get way to much absorption in the mid/high area. Any comments on that?

Here is the reverb time diagram:


And here the tone colour diagram in relation to a free field setup - dark is good:


And here a primitive 3D view from the front and then from the back:



Comments are welcome!

Thanks arttu for your comment.

Centre Speaker: I have only 62cm in height below the screen - so the speaker will go as high as possible but it's centre (where the tweeter is located) will end up aprox. 40cm above the floor. I am going to tilt it around 10 degrees upwards to fire to the listening position.
Another option would be to use an acoustic transparent screen and place the speaker behind it - but I do not really like this idea...

Wall treatment: The front wall is covered completely with absorbing material to get rid of the early reflection for the LCR sound field - but since most of the space on the front wall is covered with the screen anyway -> reflective again...
Low bass absorbers are placed in the left and right front corner, and 2 more are placed in the back of the room. The ceiling with 8mm particle board and 2cm fibreglass material in the air gab should give some (around 40%) low frequency absorption up to 400 Hz and almost no absorption for mids and highs.

I am not 100% sure of the absorption of high frequencies for the fabric - which will be either direct on the wooden panels or on a frame 5cm away from the concrete wall.

Another question - what is an ideal reverb time over the frequency range for a multi-channel dedicated cinema? Any links for this?

Yes the speakers are big...

But it's like a big car with a huge engine - you can slowly drive every where you want, even uphill without a slight chance that you ever reach the limit of your engine. And of course if you need the power sometimes - just push down your right foot!

I am not going to listen very loud, but I rather like a set of 5 (or 7) matched full range speaker where I can drive them in their linear range even when I need push up the volume a little bit. The sub is only for LFE - so the other speaker need to have a good bass reproduction and the only thing which helps there is volume.

@mbgonzomd: The name is a combination of my name and Cinema

@SteveMo: Thanks for the link

Here are some shots from the room before I started my work.

Front wall


Rear wall with main entrance door - here you can also see the small room where all the technic stuff will be going in


Rear wall and right side wall - this door leads into the party/game room


This weekend I am going to work on the air ventilation installation and hopefully can start the framing of the soffit.

Yesterday I started to work in the room ventilation. Since normally we do not have central AC in our houses here in Austria, I have to solve the problem of air exchange in an acoustic sealed HT room.

Next to the HT is a planned wine cellar and this room has a connection to the outside (I have designed this one already when we built the house). But I did somehow forget the air supply problem of the HT.
The only way to solve that is to run 2 ducts from the cinema through the wine cellar - one blowing the air from the HT to the outside and another sucking air from another room inside the basement and blowing into the HT.

Now the only problem is the 30cm (12") solid concrete wall where I have to make a 20cm x 10cm (8" x 4") hole.

Here I am going to break through - actually I will end up to make it larger...


Well to do that you need THIS:


And then after about 8 hours of hard work - it was done!



Next are the ducts, breakthrough to the equipment room for the wiring and then I can start with the soffit framing.

Damn...you are right! I should call it "The Bunker" instead of Zinema

But to answer your question - yes, here in western Europe we are used to build basements like that in areas where ground water is a problem - so this basement is water proof.

As I said in my first post, I installed a temporary solution 4 years ago in one half of my living room....still there.

The solution is far from being ideal for sound, picture, seating position, etc. - but you get used to it.

Here are some pics....

This is the front wall - Left main speaker, HTPC, equipment rack with my Yamaha DSP-A1, DIY 4:3 250cm (98) diagonal screen (way too high mounted...), center speaker, PS2 and active sub


Right main speaker - Magnat Vintage 7 series


Rear view - Sony VPL-PX20 projector, left and right surround speaker


Here a view of the couch


And some DVD's....


Had some work done in the cinema - ventilation ducts are mounted and I started the framing of the soffit - pics will follow in one or two days when I can show some good progress.

Had some progress during the last days - but would like to spend more time on my HT....but you know - job, family, ......

Here is the design of my soffit construction - inside it will be filled with insulation material.


And here another view


First step of soffit framing is mounted on the walls - the wood strips are screwed on the concrete wall with a thin layer (2mm) of isolation material in between. I hope to solve 2 problems with it - first to prevent vibration noise of the wood mounted on the wall and second maybe some decoupling of the construction against the concrete.

Here is a view of the front wall with the 2 base rows of strips


Here you can see the ducting for the ventilation and some progress on the framing


The air supply will be here in the entrance area - the short wall will be framed and covered completely to hide the duct.


Next steps are to finish the base framing, install all the tubes for the wires, mount the covers on the soffit framing and fill it with insulation.

PS: Please let me know if my images are to big or too much - I could add only links if you prefer

I have a question for the experts with experience here - is it needed to seal every single gap of the soffit to make the whole construction air tight? The last thing I would like to build is large resonator - but I guess very small gaps (less than 1mm) between the construction and the wall for example are not that bad?

The inside of the soffit will be filled with mineral wool - not too much compressed.
Of course I could use for example silicone to seal of the edges to the wall/ceiling but I would rather avoid that if there is no real benefit.

Comments are welcome!

PYD, welcome to the forum! Wish you good luck with your project.

Update: Was working a bit on the soffit framing, building the frame for the screen right now which I will need for first screen tests. I will cover it with simple white fabric for now just for testing because I will need the exact position and dimension for the projection hole in the wall of the equipment room. Further it will help me to decide on the final size of the screen....
The planned screen will be 320cm x 135cm (126" x 53") 2.37:1 with a 5cm (2") black border.
I will add some photos once it is done.

During the last week I was also working on a 3D model of the complete room - I hope I will have some renders in a week or so to post here...looks very good by now!

Any comments on my soffit question? Please....

I finished the base framing of the soffit and also the screen frame.

Next steps: Cover screen frame with white fabric for tests for projector position, install wiring for speakers and lights in the soffit, close soffit and fill it with isolation material.

And here are some shots from tonight....

Well as you can image I do not have a real problem to keep the sound inside the room.....

- The front screen wall will be covered with 1" acoustic mat (like your Linacoustic)
- In the 2 front corners I will install low bass absorbers from floor to ceiling using 4" rigid fibreglass (also some smaller versions in the back of the room)
- The soffit will have only 8mm (1/3 ") boards on top of the framing and will be filled with fibreglass mats - this will take care of low frequencies a bit
- The ceiling is a construction of 8mm particle boards spaced 1" away from the concrete - absorbs around 40% of frequencies up to 200 Hz - reflective above 700 Hz
- The walls will be covered using removable panels covered with fabric - sound treatment can be installed in there
- Since most of the surface of the room is covered with fabric I will add some wood elements to the walls which will help to reflect/diffuse high frequencies a bit. (more to see when my 3D model is 100% done)
- Carpet floor, but with "hard" surface in order to have not too much high frequency absorption

The plan is to build the room, install some basic low frequency absorbers on places I calculated with my simulation software, add all panels to the wall and then measure the frequency response. Then I can fine tune the critical areas since it is easy to remove some panels and add/remove sound treatment.

My first projected image in the HT!

Wraped the screen frame with standard white fabric and projected a 1.78:1 image (Finding Nemo).... First test passed - I like the size of it!

Now I am going to break trough the equipment room wall for the projection hole - projector will be ceiling mounted in the small room together with an anamorphic lens - the "window" to the HT will be closed later with optical AR coated glass.

9 days since my last update - what has been done meanwhile:

- closed the bottom side of the soffit
- installed 180m cables for speakers (bi-wiring all 8 speakers)
- installed 40m cables for lights and screen masking
- almost finished the 3D model of the theatre
- picked up the acoustic insulation for walls and soffit
- created detailed design of the front corner bass absorbers
- experimented with wood stains to get the right match with my fabric
- decided to make screen smaller - changed from 319 wide (125") to 270cm wide (106") after some test with seating position and feedback from my wife....

Here is the first rendered image showing the left front of the room - soffit light is still missing in the model - will come next. The textures of the walls is already using the fabric I have selected for the panels. The columns are not 100% done yet - looking not fancy enough right now.


Here the front wall - soffit construction 80% done - cables installed


Detail of the rear left side of the room


Here are 2 shots of the equipment room - cables will go into channels mounted on wall later


Here is the design of the front corner bass absorbers - I use 10cm (4") rigid mineral wool panels in 2 layers floor to ceiling


And here are the panels - the front side is black covered


Here is the insulation material for the walls - 3cm (1") thick with black cover, the other 3 rolls are for the soffit


Next steps are:
- Fill soffit with insulation
- close front side of soffit
- install front corner bass absorbers
- build front wall framing

I decided to seal all joints of the soffit with silicon to make the whole construction air tight. Since I use only 8mm thick particle boards to close the soffit front and bottom side the construction might help to reduce low frequencies but still reflect the mids and highs - of course the fabric cover will absorb some part of the high frequencies.

More pictures will come next weekend.

Thank you - I always have the impression that there is not enough progress, but that's maybe because the HT is already completely ready designed down to every single detail in my imagination..... just have to be done!


Same here....

PS: 12" solid concrete walls - so NO green glue needed here