See the CHOICE guide to digital TV for a good background on what's new and our video on home theatre audio basics.
Upscaling converts one video format to another of a higher resolution. The CIBs on test that support this feature attempt to improve the standard 576i picture of a DVD movie and upscale the image to 1080p.
The arrival of Blu-ray and 3D Blu-ray movies is making big demands on all parts of a home theatre setup. The HDMI standard of 1.4 has been introduced to help provide a framework to ensure there are no bottlenecks between the player, AV receiver, and the TV when moving those large amounts of information.
AV/lip sync allows for the difference in video and sound processing in some home theatre setups, which is responsible for a lack of “lip sync”. This potentially off-putting effect can be more pronounced when mixing analog, such as component video with digital audio from the same DVD player. All models on test have this feature.
Wireless rear speakers
Wireless rear speakers are useful if you can’t get cabling to the back or your room; the Panasonic, Samsung LG and Sony models offer wireless speakers, although you'll still need a power outlet nearby.
Standard speaker connections
Standard speaker connections allow you to upgrade your speakers if you want better sound than the standard speakers included in most CIBs. In models with non-standard connections, this task is more difficult.
Automatic calibration with microphone
Automatic calibration with microphone is a great help when setting up a system, using the microphone to take an acoustic map of the room and making the appropriate adjustments in the speaker delays to give you the best possible sound for your room. However, some units may not recognise all the speakers and adjustments may need to be made manually.
Network connectivity is becoming a regular feature of Blu-ray players, as internet connectivity is now part of the latest Blu-ray standard. Access to YouTube, Picasa and other social network applications is available on systems with a LAN (Ethernet) connection. DLNA means the home theatre system can also operate media such as video, images and audio on other DLNA devices on your home network.
An FM radio tuner is included in all the models on test, with an AM/FM tuner for the models without a DVD/BD player. None of the units incorporates a Digital Audio Broadcast (DAB+) radio.
Digital audio without video can be delivered via either an optical (TOSLINK) or a coaxial (RCA) cable if you don't use HDMI. It doesn't matter which you use, so long as the receiver and the device to be attached have the same type of connector. All models on test have at least one of each.
HDMI (High Definition Multimedia Interface)
HDMI is a digital connection via a single cord that does everything for both sound and vision. It's very handy, provides excellent quality sound and vision, and saves clutter. Version 1.3a means it can deal with a DVD or Blu-ray disc, while HDMI version 1.4 may be needed if you want the full effect of the latest 3D Blu-ray movies. All these units have a single HDMI output for a direct connection to a TV, while some models have multiple HDMI inputs to accommodate devices such as games consoles and media players.
It’s impossible to measure sound quality objectively in a store, but you can rely on your own hearing to a large degree. Take along a CD or DVD to play with music you know well, and don’t be afraid to turn it up loud. Even though you may rarely listen to music at high volume, it will be very disappointing if the product you buy can’t hack it when you throw a party.
Listen for smooth transitions from low to high notes. Low notes shouldn’t be boomy or have only one tone, while highs shouldn’t be harsh or screechy. If the store has a listening room, ask for the speakers to be placed in roughly the sort of configuration they’re likely to be in your room. Where it’s not possible to hear the system before you take it home, get the store to agree that you can bring it back if you’re unhappy with the sound.
If you’re looking for a system with a BD player, check it can handle all the music and video formats you’re likely to play, and supports all the regions you’re likely to buy DVDs from. If you have need for a particular format, it’s a good idea to take a disc to the store to make sure it will play.
Check the connections you’ll need to hook up to your TV. If the system needs separate power for the subwoofer or rear speaker, do you have enough power points? Check all the connectors and cables needed are included; they were in most of the boxed products on test.
Display and controls
Display and controls on the main unit should also be easy to understand and use so you can still use the system should you misplace the remote.
6.1 and 7.1 systems
The idea behind these systems is that extra speakers improve the system’s ability to localise sounds and smooth transitions as sounds move around the room. This may be the case, but movies are mixed for 5.1 surround sound and extra speakers won't necessarily improve the quality of the sound.
Wall mounts can make it easier to place the speakers where they're most effective in the room.
Subwoofers are bulky objects that sit on the floor, but they may not be as robust as they look. Downward firing models have the speaker facing the floor with a relatively small opening at the bottom. This might offer some protection if you have pets who like sharpening their claws on fabric, or children who may push sharp items or their fingers into a forward-facing speaker.
How we test
Our tester sets up each system so the front speakers are 2.1m, centre speakers are 2.4m and the surround speakers are 1.4m from the listener and at head height. Any non-tower speakers are placed on speaker stands near head height. He positions the subwoofer on the floor close to the right front speaker. Three expert panellists then appraise the sound quality when playing stereo sound, DVD surround-sound music, and a DVD surround-sound movie sequence. Among other things, they listen for:
- fidelity - how accurately the speakers can reproduce the content
- how well the subwoofer deals with low frequencies, and
- whether there's a seamless crossover from the speakers to the subwoofer at lower frequencies.
They move around to check the size of the sweet spot (where the sound balances and sounds best), and assess the ability of the system to localise individual sounds so they appear to be coming from a particular direction.
Our tester carries out frequency response tests to show the system’s ability to produce tones across the spectrum of human hearing (from 20Hz to 20kHz). We look at the linearity of the response and how they perform at the top end. Failure to produce tones evenly can result in unpleasant sounds or even loss of some frequencies. The results of this test may be less relevant than our listening panel results, because these tests are carried out at volumes that are at the limits of the speakers’ ability to produce sounds with minimal distortion.
Maximum output level (MOL)
Within the soundroom (a sound floor of 20dB) we connect each of one of the front speakers, surround speakers, the centre and sub to our reference amplifier at a time. The amplifier is fed a calibrated signal by our test suite. We place a calibrated sound meter at a distance of 250mm from each speaker. The sound meter provides input to the test suite. The test suite produces a tone sweep of approximately 150Hz to 20kHz and measures sound pressure level and total harmonic distortion. We know the maximum sound pressure level at 250mm and 3% total harmonic distortion and therefore can calculate the maximum listening distance at that same distortion level. We use a multimeter at the speaker to measure the voltage applied to the speaker. Using the voltage measured and the resistance in ohms stated on the speaker, we calculate the current.
Ease of use
The tester looks at the front panel display and controls, onscreen displays where applicable, ease of setting up and whether the documentation supplied is clear and useful. The power used in standby mode or equivalent (when it’s been turned off by the remote control but is still connected to the power) is measured using specially calibrated meters – the less power used, the better. To see how well systems with Blu-ray players can handle a BD with imperfections, the tester plays our specially-made test disc in each system with a BD player.
Our tester looks at how well the sizing, spacing, colour-coding, and grouping of the keys helps the user distinguish between one operation and another. He also looks at the size of the print on each key and whether any keys are illuminated when operating in low light conditions. The remote should have all the necessary functions for using the system so the user doesn't need to keep getting up to change settings.
DVD and Blu-ray evaluation is carried out by our tester, Scott O'Keefe. We test the load times of each model three times to verify how long it takes for the player to begin displaying content.
Standby power is measured by connecting the AV receivers to a regulated power supply and power meter, and records standby energy consumption.