Multimedia - Published on Wednesday, 26 October 2005 17:15 Written by tokig
One of the biggest news about X-Fi is Creatives technology that tries to improve existing recordings. The technology is called 24 bit Crystalizer and that means a few things. Mainly it is about upscaling the sound from its original format to 24 bit/96 KHz. Merely a raw upscale of the bit depth is not enough and the X-Fi-chip has to work hard when trying to figure out how it should “recreate” lost dynamics. This is achieved because the chip analyzes the sound it is feed in real-time and then tries to figure out where more dynamic is needed and how it should “recreate” it. Recreate is not the right word; because nothing is really recreated, rather new information is being added.
hen it comes to the frequency range, there is even less to be gained when a raw upscale is performed and from what we’ve understood, the chip doesn’t try to “recreate” sounds outside the original frequency range.
Another thing with the Crystalizer technology is that the sound is upscaled before it reaches the mixer and before EQ and other effects are applied. The advantage we gain here is that the effects can be applied with greater mathematical precision; which in principle means lesser round offs and truncates of data in the sound stream. Upscaling sound to 24 bit before you mix it is a custom that many studio technicians are aware of regardless if the result is a 24 bit sound stream or a 16 bit sound stream on e.g. a CD. Depending on what type of effects you apply, more precision can be gained if the frequency range is opened up to 96 KHz.
Crystalizer is looking for a sound with fast transients, in other words, sound that emerges fast, “spikes” and then disappears just as fast. Drums in music or gunshots in a game or a movie are the simplest examples. 16 bit sounds with well marked transients are often those that have to suffer the most and the Crystalizer aims to “recreate” some of the dynamic the original sound had. Because the Crystalizer works foremost with strong transients, the chip also makes sure the function is applied proportional to untreated sounds. The Crystalizer analyzes the sound data in a frequency range in order to separate different sounds that are heard at the same time. Therefore the technology is able to apply effects on a drum without noticeably changing the bass rhythm. This is achieved by treating the sound in a frequency range rather than just applying the effect on the whole soundtrack.
In order to give you a visual of what happens to the sound, you can look at the picture below:
As one quickly realizes, pronounced events in the sound picture are enhanced by the Crystalizer, while week fluctuating ambient sounds and constant background sounds remain rather unchanged. At the same time the strong transients are not allowed to “run amok” when compared to their originals. On paper, the end result is more clearly defined sounds while at the same time, the original recordings characteristic soundtrack is retained. With the users own preferences, the effect is also adjustable in 20 steps and it can off course be turned off completely if you don’t like any changes to the original.
But enough theory: To give you an image of what the 24 bit Crystalizer does practically, we have listened to/watched a handful of CDs, movies and other sound sources. To give you a more balanced view, we’ve had our loved ones making a blind test. Of course the music and movie choices reflect the writer’s personal taste and opinion and I apologize if your favorite genre isn’t represented. Also, the opinions of the 24 bit Crystalizer is highly personal, which you will understand when you read the blind tests. To make it all more interesting, we’ve tested it with music and sounds in lots of different formats.
Everything from MP3s with low bit rate, WMA with lossless compression, to DTS-soundtracks and traditional CDs. We have also tested the function in a couple of games.
Before each test I will reset the settings of the Crystalizer to the Off-mode and when it is turned on we will begin with an initial setting of 50%. Then we will search for a setting that is “just right”.
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