The Zinema construction has started! - Page 4

Thanks Mike, feel free to use the column design - that's exactly the reason why we all spend hours of reading and writing in this forum here - share ideas!!
(If you need more details from the column design/building let me know)

Just a little update on the construction - finally I managed to cut all 7 rings for the spot light holes in the soffit. They are 1cm thick and will be used to mount the fabric around the openings. The 1cm thick strip for mounting on the wall side is still missing in this picture....


I did also start to work on the ceiling - using my CAD model of the room I found the areas of the 1st reflection from the LCR speaker, did this for the front and for the rear row. Just to make sure to cover enough area I made the zones 40cm (~16") wide at the full ceiling width. For the rest I mounted 1.8cm (~3/4") thick boards (of course with foam strips) as a framing to the ceiling.


Then I will mount 8mm (~1/4") thick particle boards to the framing to cover the whole front part of the room excluding the reflection areas and the rear part. There will be no insulation between the boards and the ceiling wall - air gap of 1.8cm!


Later I will add 3cm (~1") thick "Akustikfilz" (fibreglass mat) in the reflection zones to absorb the mids/highs there. The rest of the construction should reflect most of the mids/highs but absorb some of the low frequencies (around 30% up to ~300Hz).
I did not build this construction in the rear part of the room since I will loose to much room height (even it is just a few cm) where the riser for the second row is located. The whole ceiling will then be covered with 9 fabric covered frames - 3 in the rear part directly mounted on the ceiling and 6 in the front part.

Thanks Lewis, I guess most of us (including myself) are more reading than writing...

Cara comes with a database of common materials - but you can add new ones and you can also modify existing ones. You do this by defining the absorption curve in very fine steps if you want. Same goes for the speakers - you have a selection of predefined speakers but you can also create new speakers by using the built in speaker editor. Of course when you add your own speaker the results are only as good as your provided information. The predefined speakers use measured data, the new ones will "only" use calculated parameter.

Hope that helped...

Meanwhile I received my amp for the subwoofer - I didn't want put the amplifier module into the subwoofer case so I went the route of an external amp, running with speaker cables (bi-wiring) to the sub.

Here is a picture of the amp and the technical specs:




This together with my Yamaha should give me enough room to adjust the bass management!

I have finished also the plans for the TL. It will be made from 16mm MDF which is already ordered - hope to have time to build it this week...
Since it is going to be hidden behind the rear wall framing I will keep it plain MDF for now - it's going to be an ugly large box but should sound sweet!






continued in next post....

...more pics




Making also a good progress on the room - basic framing is almost done and the carpet should go in this week....I am so excited!

Pictures of the room will follow later this week.

Steve,

I do not know the Danley sub in detail - but I guess it has also 2 drivers. So looking at this picture lets me believe it is also a build as a dual Transmission Line...

Do you have specs of the Danley?

Found the specs of the DTS-20 on the net...very nice!

It uses a single 12" driver - so it is has a single TL.
The dimensions are similar to my design but I am using one 8" and one 10" long excursion driver together in one case (each TL tuned for the specific driver) which should move even more air as a single 12" driver...

Need to build this monster this week, get an SPL meter and run some tests - just waiting for the MDF to be ready to pickup!!!

UPS just delivered my ordered screen fabric!

It's a 1.0 gain 3 layer screen material, white front layer, a very thin fibre glass middle support layer and a black back layer.

It's called Cinetec 1.30 - manufactured in Germany.
Size of fabric - 300 cm x 150 cm
Outside frame dimensions - 296 cm x 128,5 cm
Frame 8 cm wide covered with deep black velvet
Viewing size with frame attached - 270 cm x 112,5 cm - AR 2.40:1

This is going to be a very busy week!

Yesterday I finished the case for my TL-Sub - it's massive!

Here are some pictures of the construction - first a look at the MDF - 4.5m² for a single sub..


I started with the rear, bottom and left side. All glued and screwed together.


Then I built the inner part including the support pieces to give the whole construction enough stiffness.


In the next step I combined the two parts - looking like something interesting already.


Here a closed up of the 180° turn of the line for the 10 driver. The little box on the bottom left side is unused, there I will place the connection terminal.


And here I present the final housing - next I will place this monster on the rear wall behind the framing, add the connection terminal and drivers. I guess I will need a strong helping hand to move this thing - it has around 90kg, 215cm wide, 47cm high and 26cm deep.


I am not going to make it look nice since it is going to be hidden behind the rear wall framing anyway - the only target I have is to make it sound great!!

Next: Finish rear wall framing and add the wooden trim on the riser edges.

Craigo,
thank you - in fact when I started with my cinema design I had also the idea to integrate the subwoofer in the riser....

I wanted to build the Transmission Line inside the riser (like I did in my case now) but decided not to do it. Don't ask me for the exact reason for this discission, but I guess I did not feel too good to have the sub combined with the riser platform. It is more flexible like I have it now and if I have to change the subwoofer case for some reason after testing I do not have to rip apart the whole riser...

Well to build a subwoofer as an TL is not my idea....there are also some different ways to design a Transmission Line. The company producing the drivers provides also plans for building speakers - from there I had the original idea. But I had to redesign the plans since I used different drivers and adapted the sub for my room - so there is not much left from the original plan.

I hope to find time this week to continue working in the HT, I'm really wanting to test drive this baby!

Just finished the real wall framing after placing the sub along the wall.

I put the sub on a 1cm thick hard foam mat (used normally for camping beneath the sleeping bag) to avoid vibrations and to decouple it a little bit from the riser.


The sub case just fits with a 1cm gap in the front and in the back behind the rear wall framing. To avoid that the case is moving and touching the frame or the wall a placed also small strips of the foam to keep it in place.


Here a view of the left side where the 2 TL openings are located


Next: Tomorrow I will start with the wooden trim on the riser edges.

Today I started on the wooden trim on the edges of the riser platform. Cut all pieces and glued them on the riser using a special extra strong glue. Now I will let it harden and tomorrow I'm going to round the outside corners, sand the joints and fill the gaps with liquid wood. Then I will sand it again completely to get a very smooth surface ready to paint.


Close up of the right step. After the wood is painted I will install carpet on the top of the riser, on the 2 steps and on all vertical surfaces. The top surface of the wooden trim and the carpet will be on the same level - so the wood should nicely outline the carpet once finished.

Correct!

I will use 2 layers of a wax based varnish which will give a semi gloss finish when polished - so there will be some structure of the wood visible after painting.

Thanks W00lly,

welcome to the forum - the world of Thousand and One Ideas

Yesterday was a very important day for me - psychologically wise...

Carried the four columns in the garage and sanded them 2 times - didn't want to have the dusty mess in the HT!
Sanded also the wooden trim on the riser.

BUT the most important tasks yesterday: Removed all tools from the HT room and cleaned everything with the vac - took me an hour to do it right. Good that we have a central vac installed in the house (this is not very common in Europe btw) so all the dust was really leaving the room/house!

Today I'm going to close all the small gaps of the columns and riser border with liquid wood and sand it again once hardened.

Next steps: Paint columns and riser edge - then INSTALL THE CARPET!!

I know that and I believe you are absolutely right....but I fear I can not resist!!

Thanks Jason - we are all a big happy family here!

Today I finished filling the gaps with liquid wood and sanding the columns and the riser trim. Of course I had to fill the bigger gaps with several layers of liquid wood and sand it also several times - so it took longer than expected, but is done now!

All my four columns ready to paint:


And here the detail of the right step of the riser, also ready to paint:


Next: Apply first layer of varnish