|How We Tested|
|Our test PC was an AMD Athlon 64 FX 53 with 1 GB of Corsair dual-channel DDR RAM. The sound card was a Creative Audigy 2 Platinum, and the hard disk, a 120 GB SATA.
We put the speakers through an exhaustive test process, including multiple music-specific tests, a Game Test, and of course, a Movie Test.
The Game Test consisted of running the d3_c17_12 demo-a benchmark-with all the audio settings set to maximum quality. For the DVD Movie Test, we used the Fast and Furious clip from our DTS sampler.
The DTS sampler disk is a widely-used disk for demonstrating home theatre system capabilities. It contains very high-quality songs and movie clips in 5.1 surround sound format.
On the music front, the process was divided into CD Audio, MP3 and DVD Audio. The CD and MP3 tests were further divided into English and Hindi, which were then divided into instrumental tracks and vocal-specific tracks.
The DVD audio was rated on bass, treble, and vocal reproduction based on a DTS sampler disk. The songs we used were Eric Clapton's Broken Hearted and Sheila Nicholas's Faith.
For the English Audio CD Test, the vocal-specific track we used was I'm Ready by Bryan Adams; this was chosen because there is very little electronic equipment used in the song, and was performed live. The instrumental track we used was Sadness I by Enigma, because of the variety of instruments the song uses.
In the Hindi Audio CD test, we used a rendition by Pandit Bhimsen Joshi for the vocals, and Pandit Ravi Shankar's Sitar recital for the instrumental test.
In the MP3 test, the tests were performed just as above, with Dido's Don't Leave Home being used for the English vocals and Sadness I by Enigma for the instrumental music test.
In the Hindi Music test, we used the song Mitwa from Lagaan, and Strings' Anjaane Kyon for the vocals and instrumental tests respectively. All MP3 files were encoded at 192 Kbps.
Apart from these, we also tested the speakers by playing specific frequency files, from as low a range as 30 Hz all the way to 15 KHz.
We then specifically tested the bass and treble strengths of the audio systems at various volume levels using THX-certified bass and treble files.
|Root Mean Square (RMS): The sustained power in watts that an amplifier can output at any given time.
Peak Music Power Output (PMPO): The maximum power that an amplifier can output over a short period of time.
Frequency Response: The range of frequencies that the device is set to operate within.
Dolby Digital 5.1 (Dolby AC-3): Developed by Dolby, this system has five discrete sound channels in addition to Low Frequency Effects (LFE) that are directed to the subwoofer.
Dolby Pro Logic: An older standard, this packs in information for a centre and surround channel in the regular stereo channel. Essentially, there are no discrete left and right channels for the rear or surround speakers.
Dolby Pro Logic II: Audio encoded with Pro Logic II carries five channels of sound in a traditional two-channel stereo audio signal, which is then decoded back to five speakers using a Dolby Surround Pro Logic II decoder. This technology can be used on any console that does not support Dolby Digital 5.1. The advantages of using it in game applications include minimal latency, full frequency range, compatibility with existing cables, and backwards compatibility with mono, stereo and legacy Dolby Surround Pro Logic equipment.
DTS: Short for Digital Theatre Systems, this is a standard invented by Steven Speilberg, and made its debut in Jurassic Park. It uses a sampling frequency of 96 KHz with 24 bits allocated to each of the six channels. Collector's edition DVD movies normally feature two soundtracks featuring both Dolby 5.1, and DTS.
Dolby Digital EX and DTS ES: These are comparatively new standards that add an additional channel-the rear centre channel-and is implemented in 6.1 speakers. Both standards implement the rear channel in a similar way. For Dolby Digital EX, a special Dolby Pro Logic decoder is added to the surround channels, creating a rear centre channel. This decoding method first came to light with the theatrical release of Star Wars Episode 1. For DTS ES, an additional rear centre channel is supplemented to the two surround channels.
Dolby Pro Logic IIx: This is a spanking- new technology developed by Dolby Laboratories and is the first and only technology to process native stereo or 5.1 signals into 6.1 or 7.1 channel output. Different modes such as Movie, Music and Game are available with this technology, with the Music mode featuring additional user controls such as Dolby centre width, Dolby panorama, and Dolby dimension.
THX: This is an abbreviation for 'Tomlinson Holman's eXperiment'. It's not a surround sound standard, but a seal of approval that is granted to audio equipment and theatres that meet its standards. This standard is further divided into THX Select (for installations up to 2000 cubic feet) and THX Ultra (for between 2000 ands 3000 cubic feet).
S/PDIF: Sony/Philips Digital Interface; a standard audio file transfer format. Developed jointly by Sony and Philips corporations, S/PDIF allows the transfer of digital audio signals from one device to another without having to be converted first to an analogue format. Maintaining the viability of a digital signal prevents the quality of the signal from degrading when it is converted to analogue.
|How Speakers Work|
|To understand how speakers work, you need to first understand how sound works. At the very basic level, an object produces sound by vibrating the air particles around it. These in turn vibrate those next to them, and so on, until the sound reaches you.
The speaker translates electrical signals into sound by creating the requisite vibrations. Depending on the accuracy of the vibrations that are produced, we classify the speakers as good or bad!
The sound from a speaker is produced using one or more drivers. The driver produces sound by vibrating a diaphragm.
The diaphragm, which is conical in shape, can be made up of plastic, metal, and even paper! In fact, you can make basic (but bad-sounding) speakers from everyday chart paper!
The narrow end of the diaphragm is then connected to something called the voice coil. This coil is then placed in the magnetic field of a permanent magnet.
When you pass a current through this coil, it turns into an electric magnet, and will have the properties of a regular magnet-but unlike a regular magnet, on reversing the flow of current, the polarity of the magnet changes.
Now when we alternate the current flow in the coil, it keeps changing the magnetic forces between the coil and the permanent magnet. This moves the coil back and forth-due to attraction and repulsion-and moves the diaphragm along with it.
This movement of the speaker cone vibrates the air around it leading to sound production.
|Creative 6.1 6600|
|The lone ranger in the 6.1 category, the speaker has a very decent set of features, though we do wish it had a few more controls on the remote, akin to the Logitech Z5300, which lets you control everything you can think of!
The setup was fairly straight-forward (you start feeling that way after installing and un-installing 25 odd speaker systems!). The bass was trademark creative-the thumping of bomb explosions will have you running for cover. In fact, the bass is so powerful that it made CDs and other assorted items lying on our desks vibrate! The overall audio experience of these speakers was extremely impressive, though not quite exceptional.
The movie surround experience and sound clarity was really good, and when watching a clip where glass shatters, we could make out where every little piece of shattered glass fell.
In the music department, these speakers gave us really good results so long as there were only a few instruments and a little electronic mixing, but once we started running the Enigma songs, we found these speakers to be slightly low in clarity and individual sound reproduction. Also, the speakers had trouble reproducing the lower frequencies. The low frequency reproduction was better at lower volumes, but then you want your music loud, don't you?
We don't mean to imply that these speakers are bad, but we are saying that they could have been better. Then again, for just Rs 7,500, they are a steal for those who want a budgeted 6.1 audio experience.