Posts Tagged ‘HDMI’

What cabling should be installed when building?

Monday, August 31st, 2009

Legion Enterprises can precable your new home for all of the things discussed below, or if you prefer to do it yourself can supply everything you need at competitive prices.

By far the easiest time to install any cabling in a house is when it is at the framing stage of being built, with the roof and exterior cladding on, but before any insulation etc is put up. Of course, the problem is in knowing what cables you’ll need in the future for things that haven’t been invented yet. Often though, even what you need now isn’t done correctly if you leave it up to the electrician that’s doing the rest of the house. Even if you don’t terminate the cables, you know they will be there if you need them, and in the long run it can save many expensive hours running them once the house is finished, or the unsightly scenario of external cabling.

It pays to run all your cables to one location, preferably fairly central in the house to minimise signal degredation over long distances. This hub location could be in a cupboard, garage or ceiling space, but preferably somewhere reasonably accessable. You can purchase the likes of a Hills Home Hub or Hubbell enclosure which can utilise modular type distribution units, or simply screw your splitters etc onto a board. You will usually need a double power point installed too. From here cables will run to your TV aerial and/or satellite dish, all your TV outlets, Sky decoders, phone and data jacks, infrared repeaters and anything else you need. You can house your router etc for your internet in the hub as well, though consideration of wireless signals is required.

All cables should be labeled at both ends
. There is nothing worse for an installer than getting to a job and finding there are 20 or more cables with no idea of which one goes to where. Labels can be as simple as white electrical tape with the name of the room written on it. Make sure the labels aren’t right at the end of the cable or they will be cut off when the cable is terminated – 150mm from the end is pretty safe.

As a bare minimum we recommend that you have the necessary cables installed for a Sky decoder (including a phone jack) in the lounge and the dining room as well as to reticulate it to other rooms in the house. Standard TV points should be installed to the lounge, dining and master bedroom if not to the other bedrooms too.

With Sky’s MySky HDi decoders fast becoming the standard Sky decoder, and the introduction of Skys quad LNB, there is a need for more coax cables to be installed. Each HDi decoder (or position where one may be installed) should be configured with dual coax feeds for the dish, an aerial and return feed, as well as a phone jack.

Wall mounted flatscreen TVs seem to cause people a few problems. Firstly ask your builder to put extra timber in the wall to fix the TV mount to. A 10″x2″ between two studs at the height you think you want the TV centred at is ideal (often there is an offcut from a beam lying around), but even a 4″x2″ is better than nothing. Make a note (and take photos) of where it is! As far as cabling for a wall mounted TV goes, you’ll need to decide where you will have any AV equipment (DVD players, Sky and Freeview decoders, home theatre receivers etc) and run, as a minimum, HDMI and RF cables. You’ll also need a power point for the TV. Modern high end Home Theatre (HT) receivers can take just about any video signal, and upscale it to HDMI, so you would only need the one HDMI cable to cover most bases, and the RF cable to feed UHF signals to a TV with Freeview in. If you don’t have a fancy HT receiver, or none at all, you will need more cables. For a more basic receiver component and composite video cables are usually needed. If you don’t have a HT receiver at all, you’ll also need stereo audio for both of those cables. The HDMI cable will be needed in the future, so don’t leave it out even if you don’t need it now. If doesn’t hurt to put in a length of Cat5e (or Cat6) from the TV to where your AV equipment will be housed, as well as one back to the hub location. The Cat5e can be used for phone, data, infrared, as well as a number of other things.

Projectors aren’t overly common but they can certainly be a great addition to your Home Theatre setup. Cabling for them is fairly straight forward. Have the electrician install a power point on the ceiling (check your projector’s specs for the optimum distance from the screen), and the builder add timber in line with the centre of the screen for the mount. Modern projectors will take an HDMI feed, and that may be all you need. Others may need component or S-Video (you may want to put one or both of these in to keep your input options open).

Data cabling is to some degree becoming more redundant with wireless technology improving all the time, but there are many scenarios where it is still very useful. With more wireless products available, there is more chance of interference, which may not stop it from working, but it may cause speed degredations – correctly installed wired cable is virtually immune from interference. Speeds are still much better through cable – 1000Mb/s compared to 320Mb/s. More and more devices are becoming internet ready too, MySky decoders, TIVO, game consoles, TVs etc, and many of these need to be hard wired, or use expensive wireless adapters. Use of Media Centre type PCs is also on the rise as an alternative to TIVO type boxes. Consider installing data cabling to any Sky points, main TV locations, and the study. Wireless can then be used for any laptops and other portable equipment.

Infrared repeaters allow the use your remote away from where the actual device is housed. This may be as simple as changing the Sky channel from another room, or you may want all your Home Theatre equipment out of sight in a cupboard. As with data cabling, it can be done wirelessly, but there are often interference problems, and it usually costs more to get extra receivers than to use a multiroom wired system. Most wired systems will use Cat5e cabling, with a receiver by each TV, and transmitters at the equipment end. The unit itself is generally installed in your hub.

Surround sound speaker cabling is often overlooked, despite a large percentage of people now having a surround setup of some sort. The cabling you install will depend largely on your choice of speakers. Small satellite speakers can be installed up in the corners of your room, and don’t require a heavy gauge cable. These usually don’t need to be terminated at a wall socket at the speaker end as the speaker is often mounted right over where the cable emerges through the wall. Larger floorstanding speakers will require larger cable of at least 1.5mm or you may lose clarity in the lower frequencies and are often terminated to a wallplate.

The Great HDMI Cable Scam

Friday, March 13th, 2009

For many years now, when buying Home Theatre equipment the sales people have tried to talk you into buying expensive cable and interconnects. Things now seem to be coming to a head with many retailers selling very expensive HDMI and Toslink audio cables.

In the past there has been a noticeable difference in picture and audio quality when using a very cheap analogue cable, and a more expensive analogue cable, though the difference between say a decent $50 cable and a $500 cable is usually negligible to the average joe, compared to the difference between a $5 cable, and the $50 one. One of the reasons here being that there aren’t standards in place for the analogue cables of yesteryear. Many cheaper AV cables don’t even use coaxial cable for the video signals. Higher grades of cable usually use plenty of copper, often oxygen free (retarding the formation of copper oxides which affect the signals passing through them), the correct type of cabling for the job, and good quality connectors on the ends.

With the new generation of digital cables, there are standards which the manufacturers should be adhering to. As long as those standards are met, then the signal will get through. Cheap HDMI and digital audio cables generally perform just as well as the expensive ones. Certainly there are quality differences in areas like strain relief at the connector and the overall appearance and feel of the cable, but as with the analogue cables mentioned earlier, there is very little difference even in that once you get past a certain point.

Things like fancy braided cloth coverings, super thick insulation and even gold plated connectors have no bearing on the way an HDMI cable will perform (in fact we’ve found the more expensive, thick cables are very rigid and often hard to feed through cabinets and get plugged in, and the bulky connectors used can interfere with plugging something into the next socket). There have been a number of studies conducted that give conclusive evidence to back up what has been written here. Choice’s results speak for themselves, and there are many more you can find on Google if you feel the desire.

We’ve come across many people who have been convinced when buying new TVs and other equipment that they need to spend hundreds of dollars on cables to get the best out of it. One of the more well known cable manufacturers sells a 5 ’speeds’ of HDMI cables, despite there only being 2 standards, justifying the need for higher speed requirements by talking about future technologies, and comparing their best cables with ‘the worst cable that I’ve ever seen’ on their website. The standard speed cables, and any before version 1.3 are fine for Freeview (assuming they are built to spec), as it doesn’t exceed 1080i which these cables are tested to. Version 1.3 and later high speed cables are tested to, and beyond, 1080p specs used in PS3 consoles and Bluray DVD players. Don’t be confused by the version 1.3, 1.3a and 1.3b numbers as they have no impact on consumers.

We don’t suggest you go with the cheapest cable you can possibly find as the build quality does factor, but certainly don’t be sucked in by the sales pitch of ‘Ultra Speed’ or the like $300 cables.

Other reading

hdmi.com – A lot of information about the HDMI specs, requirements etc.
Mauricio Freitas blog post – a Kiwi blogger, the comments make for interesting reading too.
Unethical cable comparison – An example of an unfortunately common practice of comparing an expensive HMDI cable, against a completely different and outdated analogue format cable, or different length HDMI
A forum post from a broadcast engineer – The difference between digital HDMI signal and analogue signals in extremely easy to understand terms.

Do I need a High Definition TV to use Freeview HD?

Tuesday, January 13th, 2009

No, your older TV will still receive the pictures and audio for all channels from a Freeview HD decoder, but they will be in Standard Definition (SD). Chances are they’ll still look a lot sharper than the analogue pictures you’ve been used to, though they’ll pale in comparison to HD pictures. All Freeview HD decoders are equipped with connections that can be used with your older TVs, though there may be a very few that don’t have RF outputs (the type of socket used by your TV for the aerial), so if your TV is really old and doesn’t have any AV inputs (coloured RCA sockets), make sure the decoder has an RF output.

The Freeview approved decoders will output HD only from an HDMI socket, but other non-approved decoders may also output HD on component. Component is capable of HD pictures up to 1080i (which is as high as Freeview goes), the RCA sockets on the TV are often labelled Y, Pb and Pr, and are coloured red, green and blue. Audio is transmitted separately via two RCA sockets coloured red and white (or occasionally black). Note that not all component inputs on TVs are created equal, more often than not, they are not capable of HD pictures, but check the manual as you may have one of the ones that does.

When the time comes and you do upgrade your TV to an HD capable TV, it’s simply a case of plugging in an HDMI cable (usually supplied with the decoder), and you’ll be up and running in High Definition.