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Momo's Media Wall
Early 2007 we (my wife ) decided our 20+ year old living room furniture had had it. We ordered new stuff. So I had a really good excuse to also invest into AV and replace the 25-year old 17-inch Philips TV and mini stereo.
I had dreamed some time already about a nice HTPC. The Hush silent PC's was what I had in mind. Add a PC surround system and a PC monitor and done.
The monitor indeed I have now. A beautiful Dell 3007 30-inch LCD. I just don't like those TV's with all the useless cabinett surface around, and speakers I don't use anyway. I am still very satisfied with the monitor choice.
Speakers is a different matter. As soon as you dive into it a little bit, you find that the PC stuff just does not deliver the right audio quality. So the dream of having only that HTPC and no other electronic boxes in the living room was gone. And then the xyl wants as little equipment visible in the living room as possible ...
So the idea came up to hide the whole stuff behind a wall.
The sitting corner of the living room ends in a 3.20m x 2.20m wall, with 13cm wooden beams in front of it left, right and on top. So the idea was born to close this space by 10mm plasterboard, and use the remaining 320 x 220 x 12 ccm space for AV: The mentioned monitor, speakers, HTPC, preamp, amp. And light for the living room, by the way, would also be nice.
There should be as little AV clutter visible in the living room as possible: I think I have achieved this. Not a single wire, cable, or box is visible, only the screen and the speaker covers, flat in the wall. Outside of it only a (RF) remote control for the family and wireless keyboard/mouse for the more advanced users.
I was not so naive as to assume once assembled I wouldn't need to touch the electronics any more. So I needed a way to open the wall. But I didn't want visible doors. The front should just be a wall, covered by woodchip wall paper as the rest of the living room.
Inspired by the interior of a Japanese Hotel (in LA actually), we came to the idea of closing part of the wall by Japanese-style paper panels (may the Japanese please excuse my crude imitation of their traditional handcraft). We like the resulting look, and since the panels are held only by magnets, I can remove them in two seconds.
Since I have only 11 cm between the wall and the shoji, I needed a very flat PC, still featuring a good graphics card, and silent operation. After looking around I decided I have to build it myself. I got me a nice Asus motherboard, a standard boxed Core2Duo (the fan is typically running at about 800rpm, practically silent) a passive nVidia 8600 graphics card, a silent power supply, and two 2.5 inch disks (in Raid0 configuration).
Because of the height limitation, I could not put the graphics card just into the PCIe slot, but had to mount it in parallel to the motherboard, connected by a riser card. To hold the stuff together and for mounting it onto the wall, I used two aluminium sheets, as shown in the pictures below. (A thought behind that was originally to use passive CPU cooling, with a heat pipe connecting the CPU to the aluminium sheet. But I did not find the right components to achieve this.)
The whole idea of the wall was co-developed with a friend who is a hobby high-end loudspeaker designer. He recommended the drivers (as mentioned in the component list below) and the layout for me, and it worked great.
For the same reasons as mentioned with the HTPC above, and once in DYI mode, I decided to build the audio amp myself, too. And I think I have now an excellent solution.
Of course I wanted to use the S/PDIF digital audio output of the PC (integrated into the motherboard). You typically connect it to a "A/V receiver". Again a big box that can do a lot of stuff I don't need (like video switching). It may contain also power amps (or you need another box), and then you typically route the amplified audio through a crude analog crossover network to the loudspeakers.
Luckily, I found the dcx2496 mentioned below. It does S/PDIF decoding, digital crossover (including all sorts of equalization etc), D/A conversion and pre-amplification for up to 6 channels. I use only 4, for left and right tweeter and woofer. All contained in a 1U 19-inch unit that I mounted in the right shoji compartment.
I struggled some time with the connection between the S/PDIF RCA-type output of the PC and the XLR AES/EBU (spdif compatible) input of the dcx2496. Here is what I finally used: RCA-BNC adapter; BNC coax cable from the left the the right shoji compartment; Neutrik NADITBNC-M adapter; short XLR cable to the dcx2496.
The tweeters are highly efficient and need not much power. I use the much-appraised Sonic Impact T-amp (or rather, the board contained in this cheap amp). It is a class D digital amplifier with excellent performance.
The woofers need some more power. I found great amps made by a small Spanish shop: Coolamp. Also of class-D type, they provide 400W each, with minimal standby dissipation, high efficiency, and excellent audio performance.
I mounted the amps (together with a switched PSU from Coldamp and an old laptop PSU for the t-amp) on another aluminium sheet, and mounted them in the right shoji compartment.
I will report on measured audio performance later ... will be excellent ...
We also needed better light in the living room, so why not also add that? So I added Philips low-profile Pentura light strips along the sides of the shoji compartments. A total of 400 watts of fluorescent light, enough for all situations needing a lot of light in the room. I added a 60-watt incandescent bulb to each side for comfortable home-theatre backlight.
Of course, also the light installation is completely in the wall, meaning no switches. So I needed remote control. I decided for the FS20 system (Conrad Electronics). With one remote I can switch the different lights, the amp, a pair of power outlets behind the sofa, and the PC.
For the PC on/off I added a small relay allowing me to completely power-off the PC and to restart it. (I will add some details of this later).
My Wifi base station also found it's place in the wall.
Well, the whole thing, as you can imagine, took some time to create. But now I have a fantastic solution. At least the basis of it. The remaining challenges are mainly on the software side. Understanding the details of MediaPortal will still take me a while. I still want the server to shut down automatically and be woken up by the clients. The X10 remote does not yet work as it should. And then of course I am waiting for MediaPortal 2 ...
In the basement there is a simple server, with a couple of DVB-S cards, and ethernet connection to the home network.
In the living room the Media Wall. And the other 4 PCs of the family members also have MP installed. Works nicely even wireless on a laptop.
- Case: none: motherboard mounted on aluminium sheet, screwed to he wall, covered by Shoji
- Mainboard: ASUS P5KR
- CPU: Core2duo E6600
- RAM: 2x 1024MB Corsair
- PSU: Deltatronic fanless
- Videocard: Asus EN8600GT Silent 512MB
- HDD: 2x WD 80 GB Sata in Raid0
- Soundcard: onboard, S/PDIF
- OS and Apps: Vista Ultimate + MP
- Remote: X10 (not working well yet)
- Display: Dell 3007WFP (30-inch LCD)
- Pre-amp: Loudspeaker mgmt system Ultradrive Pro DCX 2496 (www.behringer.com/dcx2496)
- Tweeter amps: Tripath board ripped out of a Sonic Impact T-amp
- Woofer amps: 2x Coldamp BP4078 400W class D amplifiers (www.coldamp.com)
- Tweeters: 2x Boehlender Graebener Neo 8
- Woofers: 2x SLS8, with 50 litres of damped air in an unusual form factor for each of them
- other: (cables, connectors, adapters, rc, light ...)
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