Over a year after it began, the whole-house-audio project is complete. 4 rooms around the house can now be filled with the sound of any of (currently) 4 audio devices thanks to a mixture of hardware and software.

The project had a slightly rocky start, with a prototype not functioning at all and partly destroyed amplifier (which was thankfully fixable by replacing a couple of components). A software alternative was considered at one point, to avoid too much expensive hardware. The hardware solution proved to be less complex and more likely to work.

The living room, dining room, kitchen and master bedroom are host to a pair of speakers each, connected to matching 240W rack-mounted amplifiers housed in my home-made full-height 19″ rack cabinet. The cables that carry the audio signals to the speakers were installed along with 24 runs of CAT5 before moving into the house.

The audio is routed to the amplifiers via an 8×8 VAMS-0808 AV matrix switcher, which allows the 8 outputs to take their inputs from any of the 8 available sources. Only 4 of each are currently in use, so there’s plenty of room for expansion.

4 audio sources are connected via simple custom-altered CAT5 cables, which simply transmit line-level signals over the existing twisted pair infrastructure installed in the house. These sources are currently the DAB radio in the kitchen, the TV in the living room, the computer in the dining room (for playing CDs) and a second DAB radio in the master bedroom.

I’ve written the software to control it all using .Net (C# of course), running on mono on linux. There are four components to this:

1. To control the matrix switcher, I have written a library which communicates with the VAMS-0808 via an RS232 serial connection. The software can perform any of the operations that can be performed via the front panel of the device, apart from switching power on and off.
2. The amplifiers are connected to an APC AP9212 MasterSwitch Power Distribution Unit which was bought with this project in mind. Controlling this is slightly less straightforward and not quite as elegant. The library that I’ve written for this communicates through the telnet interface of the MasterSwitch to turn devices on and off.
3. Combining these two libraries is a simple web server which presents an equally simple XML-based web service. The service allows room inputs to be changed and switches the amplifiers on and off as necessary. This runs on a low-power disk-less computer running Ubuntu, hidden within the rack cabinet.
4. A touchscreen web interface acts as a front-end to the entire system. The simple menu system uses iUi for a clean touchscreen-friendly design. As with the web server this runs on a low-power machine, although this one has a small hard disk and runs Windows due to technical issues with the touchscreen.

There is currently just the one controller front-end, located in the dining room. To listen to the kitchen radio, for example, all that is necessary is to select the ‘Kitchen DAB Radio’ option from the main menu, then select which of the 4 rooms to play it through – or all of them if you are going to be wondering around most of the house.

Future extensions

Thanks to building the web interface with iUi, the system is compatible with the iPod Touch and iPhone, so they can instantly act as frontends for audio control. A second fixed controller may be added in the master bedroom in time, if there’s enough money available. Each front-end costs about £200 in hardware, depending on what bargains can be found on eBay.

The matrix switcher supports both audio and video. Only the audio channels are used at the moment, so there is the very real possibility of using the remaining 4 output zones to connect to TVs around the house and adding some AV sources. This way it’s instantly converted into a whole-house-AV system. The video signals can be carried over the twisted pair CAT5 cables like the audio, but will require a little more hardware to preserve quality. This hardware is relatively expensive, although savings can be made by building the equivalents by hand. Following the tradition of this project, that’s probably what I’ll do. I have done it before while I was at university and it works beautifully.

The audio system that I’m building requires 2 low-power computers: 1 for the touchscreen controller (not using an iPod Touch for the moment) and 1 to act as a webserver and serial-console server.

Once again eBay has come to the rescue, and by searching for ‘geode’ – a low-power processor for Thin Clients & Small Form Factor (SFF) PCs – I found the 2 machines that I needed. These are the specs:

magnesium (the black one)

• 800 MHz Geode
• 256 MB RAM
• 6 GB CF drive
• Onboard graphics, audio, serial, parallel, USB & 10/100 ethernet

£70 + P&P

potassium (the grey one)

• 300 MHz Geode
• 256 MB RAM
• 6 GB 2.5″ IDE drive
• Onboard graphics, audio, serial x2, parallel, USB & 10/100 ethernet

£35 + P&P

Magnesium is used as the client machine, and potassium runs a custom-made webserver and the control software for the VAMS-0808 Matrix Switcher.

Both came pre-installed with Puppy Linux, a lightweight distribution designed for low-power machines such as these. It runs surprisingly quickly, but to make it easier for me to maintain I decided to install Ubuntu.

On such slow computers it took many hours to get Ubuntu installed on magnesium alone. I initially installed to the CF drive that came with the machine. However I found it to be quite slow, so I followed a guide for running Ubuntu via network boot and removed the CF disk. I did the same for potassium. Both booted off of the fileserver, boron.

Unfortunately during installation, I found that the slower of the machines has a tendancy to overheat causing the machine to hang. To get Ubuntu installed I had to remove the case. This has now been rectified by installing a blower to get at least some air circulating. This is the only fan in either of the machines. Magnesium gets quite hot but has never crashed because of it. It also sits in a cooler environment, and is much better engineered.

Sadly I’ve been forced to install Windows XP on magnesium purely because I couldn’t get the touchscreen to work under linux despite spending more than a day trying to. While it was detected, and it detected touches, the calibration was completely off and there was no way to configure it. Rather than waste any more time I decided to switch to Windows and everything has worked beautifuly since then. To accomplish this I’ve had to reinstall the CF disk since as far as I know XP Pro can’t do diskless booting.

Shots of these computers in use and more information on their roles to come soon.

• Digital terrestrial, received through a suitable TV antenna (DVB-T)
• Cable, in most cases through Virgin Media (DVB-C)
• Sky (DVB-S)
• Freesat (DVB-S/DVB-S2)

My MythTV installation is currently solely using a dual-tuner DVB-T receiver to record TV. However we are right on the edge of the closest transmitter’s reach with no usable overlap with any other transmitter, so at best our signal is spotty.

As spring progressed and the trees regained their leaves our signal has gotten weaker and weaker to the point that about 90% of recordings fail due to a lack of a signal lock or a very weak signal producing something that’s unwatchable.

The TVs in the house cope slightly better, but still suffer a lot from a broken signal. With digital being all-or-nothing compared to analogue’s degrees of static snow, it’s either you can watch something or you can’t… unless we change to the analogue tuners in the TVs, which we often have to.

We are being forced to consider alternatives, either to back up terrestrial or replace it completely.

I’m keen to keep to things which can be used legally with MythTV, which would rule out Sky and Virgin Media which essentially bind you to using their hardware. The benefits of those two services however is that they have a more complete selection of channels as well as the option to upgrade to significant bonus content, compared to the one remaining alternative – Freesat.

Freesat was launched recently by a collaboration between the BBC and ITV. Most of the transmissions are in Standard Definition (SD) with a small sprinkling of High Definition (HD) services. More channels are expected to sign up, but at the moment there’s all of the UK BBC and ITV channels plus Channel 4 but at the moment no Channel 5 (who seem to insist on transmitting encrypted signals). Also there are none of the UKTV-owned channels including Dave.

Freesat is transmitted unencrypted over DVB-S & DVB-S2, both of which can be received by a computer using an appropriate satellite receiver card. Naturally I’ve been keeping my eye out on eBay for such cards, and there are usually a few on at a time. I’ve not bought any just yet and I won’t until a decision is made for sure that we’re going for Freesat rather than the next alternative, cable.

DVB-S2 is used for carrying HD programmes. It is relatively new, so although there are PCI cards out there cable of receiving the transmissions, the software for Linux hasn’t caught up yet. MythTV is in the early stages of including support, and some basic drivers are available. The cards come with software for Windows, but that’s not much use for a distributed MythTV-based PVR. I’m hoping that at least I can get DVB-S working for recording and such, then upgrade to DVB-S2 when it’s reliable. In the meantime HDTV can be watched on a normal set-top box.

Before Freesat came on the scene, as already mentioned the next alternative was cable from Virgin. In my investigations it quickly became apparent that connecting a DVB-C card (a rare thing in the UK) to Virgin’s cable network was not a good idea since it would almost guarantee disconnection of all services including my 20 meg broadband.

To keep within the T&Cs of that means using the analogue output from the V or V+ box, connecting it to a capture card and then doing digital->analogue->digital conversion. The result of this would be relatively low-quality video and audio, at a limited resolution (SD only). An IR transmitter would need to be used to control channel changing, and since it uses the only externally-available tuner you couldn’t watch one channel on TV and let another record on the same box. It’s certainly not an elegant way of doing things.

If we were to go for Sky, a similar thing would probably have to happen, although with a little work it may be possible to get a PCI DVB-S card to work with it, provided it had support for a decoder card so that the signal could be decrypted.

In the likely event that we decide to go for Freesat, the cheapest solution would be to do a complete self-install. However the easiest solution would be to pay for installation of a single-room service. We will need a 4 room service however, so the plan is currently to pay for a single room installation at £80, then buy a quad LNB and run the 3 other cables ourselves. That way we don’t have to worry about getting the correct size dish, mounting and positioning it. Apparently there’s some satellite-grade coax around somewhere that should do the job.

There will probably be 2 tuners in a machine that will do the recording (possibly boron) and the other 2 runs will go to the living room and the master bedroom.

Naturally there will be photos and such if/when the project takes place.

Yesterday I completed and successfully tested the control software for the audio system. The software works with the matrix switcher and the APC MasterSwitch remote control PDU to allow the audio output devices around the house (TV, radio, CD player etc.) to route their sound to any of the 4 audio zones.

I’m now waiting on some more purchases from eBay to arrive before I can finish the system off. On the way is a small touch-screen monitor and a low-power mini ITX computer to connect it to. This will function as the controller and will probably sit in the dining room at the centre of the house. I’ve not gone for an iPod just yet, since a small mobile device has the possibility of getting lost or damaged more readily than a fixed controller. I’m looking out for a cheap 2nd hand one on eBay though.

Although I had got the software working yesterday, I foolishly installed some updates for Ubuntu and now the serial ports have disappeared again. Rather than battle to get the ports to show up and behave I’ve gone a little more eBay crazy and bought a second thin-client-like low power PC which will run the matrix control software and possibly the web server for the front-end control interface.

The other remaining tasks include creating some more cables and positioning and attaching the speakers for zone 4, the master bedroom.

Full details of the setup, with a video, will hopefully be posted in the next few weeks.

The speakers for zone 2, the dining room, have been installed without much of an issue. They sound pretty good after a test of zones 1, 2 & 3 using the DAB radio in the kitchen. The left-hand speaker helps to hide the cable route from the pantry to the dining room & kitchen.

One of the things that has been lacking in my bedroom is a TV. I can watch recorded TV programs, DVDs and other videos on my PC, but not at the same time as relaxing on my bed. While I had a week off work I was looking around the Dabs website and ventured across a real bargain of a TV (now discontinued). It supports full 1080p HDTV as well as being a relatively huge 37″ all for just £539. I couldn’t pass this by, so I spent a while doing investigation work and finally decided to take the plunge and buy the thoroughly indulgent item.

When I designed the rack, the idea was that I would eventually get an LCD TV and it would be mounted to the side of the rack. However, it now contains so much equipment that the weight has become a bit of a concern. To avoid problems with the rack castors collapsing under the load – or even the floor of my bedroom doing the same – I decided to mount it in a more traditional location, on the wall at the foot of my bed (though I had to turn my bed around to make it the foot).

Now I needed something decent to connect it to, with the ability to run MythTV and watch video at possibly 1080p resolution. Boron used to live in a HTPC case, but it started getting a little crowded and warm and with the construction of my rack the innards were moved to a 19″ case. That meant that I’ve had a spare high-quality case lying around doing nothing for a while. Now I had the opportunity to bring it back into service.

The Core 2 Duo in my gaming machine has done nothing but impress with its performance and cool running, so I knew what I wanted to base this new machine around. The E7200 2.53GHz was the cheapest Core 2 available on Dabs, so into the basket it went. I wasn’t too bothered about having a high-spec for the rest of the system, and indeed it needs to be farily quiet and cool so for graphics I went with the Asustek Radeon HD3450 256MB and a cheap-but-capable Gigabyte motherboard.

The processor ended up getting swapped for the slightly slower one in aluminium, so I got a small upgrade for gaming at the same time. For the OS I’m currently experimenting with MythBuntu for amd64. I’ve also taken another look at LinuxMCE, which I might give a go some time.

The new machine was named barium, and sits fairly neatly under my bedside table.

Audio zone 3 is the kitchen. This is one of the rooms that has not been decorated yet, so I can afford to do things without much consideration for any damage to the paintwork and I’m not constrained by the current styling. In the end I opted for some cheap Bose-clone speakers to hang high on the wall down the far end of the room, partially hidden by a supporting beam.

Unfortunately they arrived a little smashed up, but a little glue fixed them.

As with the data cabling, the trunking for the speaker cables will probably be removed when the time comes to decorate the kitchen, and the cables will be run into the plaster.

There are 4 audio zones in the house, each requiring it’s own amplifier and pair of speakers. I’ve just purchased the last of the amplifiers, which completes the selection of hardware that’s necessary within the cabinet. I took the opportunity to rearrange the order of things in the rack a little to tidy things up.