Sound Blaster X-Fi

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Sound Blaster X-Fi XtremeMusic

Sound Blaster X-Fi is a PCI sound card from Creative Technology. It is an add-on board for PCs.

1 Overview
- 1.1 Criticism
2 X-Fi features
3 Current X-Fi line-up
4 See also
5 References
6 External links

[edit] Overview

The X-Fi (for "Extreme Fidelity") was released in August 2005 and was initially released in XtremeMusic, Platinum, Fatal1ty FPS, and Elite Pro configurations. Three additional models were added in October 2006; the X-Fi 'XtremeGamer', X-Fi 'Xtreme Audio' and the X-Fi 'Xtreme Gamer Fatal1ty Pro'. The 'XtremeGamer Fatal1ty Pro' is a mainstream gaming model which is identical to the high-end gaming Fatal1ty FPS but lacks the additional I/O box and remote control accessories; the 'XtremeGamer' is a model optimized for gaming which lacks the I/O extensibility of the higher end X-Fi models; the 'Xtreme Audio', despite the "X-Fi" label, is the only product in the X-Fi line not using the X-Fi chip (CA20K1)[1] but an older chip similar to the Audigy SE and SB Live! cards (CA0160-WBTLF)[2] and thus lacks the hardware acceleration of 3D sound and EAX sound effects, gaming and content creation features and the I/O extensibility of all the other X-Fi models. Creative also released an external solution (named x-mod) in November 2006 which is listed in the same catagory as the rest of the X-Fi lineup, but is only a stereo device, and lacks the specifications of the internal offerings.

The 130 nm EMU20K1 audio chip operates at 400 MHz and has 51 million transistors. The computational power of this processor, i.e. its performance, is estimated as 10,000 MIPS (million instructions per second), which is actually about 24 times higher than the estimated performance of its predecessor—the Audigy processor. It is interesting to note that the processor’s computational power is optimized for the work mode selected in the software. With the X-Fi's "Active Modal Architecture" (AMA), the user can choose one of three optimization modes (Gaming, Entertainment, and Creation), each of which enables a different combination of the features of the chipset. The Xtreme Audio model lacks the EMU20K1 chip and thus only supports the "Entertainment" mode via software emulation, while all other models support all three modes. X-Fi models that support "Gaming" mode use EAX 5.0, which supports up to 128 3D-positioned voices with up to four effects applied to each. The X-Fi, at its release, offered some of the most powerful mixing capabilities available, and made it a powerful entry-level card for home musicians.

The audio processor on X-Fi was by far the most powerful at its time of release, offering an extremely robust sample rate conversion (SRC) engine in addition to enhanced internal sound channel routing options and greater 3D audio enhancement capabilities. A significant portion of the audio processing unit was devoted to this resampling engine. The SRC engine was far more capable than previous Creative sound card offerings, a limitation that had been a major thorn in Creative's side. Most digital audio is sampled at 44.1 kHz, a standard no doubt related to CD Digital Audio, while sound cards were often designed to process audio at 48 kHz. So, the 44.1 kHz audio must be resampled to 48 kHz (Creative's previous cards' DSPs operated at 48 kHz) for the audio DSP to be able to process and affect it. A poor resampling implementation introduces artifacts into the audio which can be heard, and measured as higher intermodulation distortion, within higher frequencies (generally 16 kHz and up). X-Fi's resampling engine produces a near-lossless-quality result, far exceeding any known audio card DSP available at the time of release. This functionality is used not only for simple audio playback, but for several other features of the card such as the "Crystalizer".

The 20K1 chip is able to utilize a significant amount of RAM to store sound effects for faster and improved processing, just like the previous E-mu 10K-series and E-mu 8000. This feature, dubbed X-RAM by Creative and found on the higher-end models in the X-Fi line (the Elite Pro, Fatal1ty and XTremeGamer Fatal1ty Pro Series), is claimed to offer quality improvement through audio processing capability enhancement, in addition to further reduction in host system CPU overhead.

In 2007 Consumer Electronics Show, Creative Technology unveiled PCI Express x1 and ExpressCard/54 versions of Sound Blaster X-Fi Xtreme Audio.[3]

[edit] Criticism

The X-Fi-series has been criticized for the way it has been marketed. This criticism mostly centered on the optional "Crystalizer" functionality—a DSP function which colored the sound in an attempt to improve perceived quality. Creative claimed that this Crystalizer DSP could generate 24-bit resolution from audio recorded at 16-bit, a claim which is mathematically and logically impossible (although one could say that by doing it in a 24-bit domain, you are in fact creating 24-bit audio). In fact, Crystalizer is similar to the countless plugins that are available for digital audio players. Since the technology is proprietary, Creative has not released a great deal of information into the technical workings; only to describe it as a "signal-dependent, dynamic EQ"[4], where as other testing has determined it's closer to a multiband compressor. Whether or not the effect is beneficial is a qualitative measurement unique to each individual, and depends on the type of audio being played back.

As of March 2007, there has been no Linux support; Linux users are unable to generate any sound from the card. Creative, on May 18th, 2006 issued a statement that a closed-source Linux driver that works with the Advanced Linux Sound Architecture will be available in the second quarter of 2007.

The entry-level model of the X-Fi series, the Sound Blaster X-Fi Xtreme Audio, does not actually use the X-Fi chipset but is actually a rebranded Audigy SE, as it uses the same family of chips (CA0160-WDTBF), and even the same drivers. Thus, not only is all of the X-Fi related processing done in software, but it also lacks basic hardware acceleration just the like SB Live! 24 bit, the Audigy SE and other budget Soundblaster models. This is further confirmed by its not using the same drivers as the rest of the X-Fi family, its not being recognized as X-Fi capable hardware by some modern games, and even in the similarity of the card's profile to the older Live! and value Audigy series, as well as user reports of it slowing down applications and games. [5][6][7].

[edit] X-Fi features

The Sound Blaster X-Fi presents the following features, which are usually implemented with the aid of the X-Fi DSP or in software, in the Xtreme Audio model

24-bit Crystalizer

Creative Labs states that its primary function is to "restore portions of the sound which were lost during compression", something mathematically impossible. In practice, the Crystalizer is a dedicated, dynamic graphic equalizer. The main function of the Crystalizer is to enhance low and high frequencies to create a more puncy sound experience which can often be lost during compression. Other functions include modifying a certain range of frequencies in order to achieve better perceived sound quality on a wider array of equipment such as headphones and speakers, and also to digitally increase the volume by about 3db. The Crystalizer emphasis can be adjusted between 0-100% when enabled, however even at 0% the audio is still processed partially. As a consequence of enabling the Crystalizer, the original signal is altered, and whether the result improves upon it is purely a matter of perception and can depend on the type of audio being played.

CMSS-3D

This feature is intended for both headphones and speakers. CMSS-3D consists of 3 settings depending upon what equipment is used. With 2 speakers, CMSS-3DVirtual can be enabled for virtual 3D audio. If surround sound speakers are used, CMSS-3DSurround can upmix stereo sources up to 7:1 channels. There is also CMSS-3DHeadphone for virtual 3D audio when using headphones. Whether the results are desireable can depend upon speaker equipment and personal preference.

EAX Effects

Environment Audio Extensions is designed to be enabled by game developers within a game to enhance the "simulated-reality" the user is modifying. There are also 8 build-in effects which can be applied by the user to the audio.

This is Smart Volume Management. It is a compressor or normalizer that tries to keep the volumes of various audio sources equal. It does alter the original recording so it may or may not be a desired option. It can be useful depending upon what audio is being played, or if two audio sources are being played at once.

Graphic Equalizer

This function divides music into ten frequency bands, which can be adjusted using the sliders. The EQ, like the 24-bit Crystalizer, is a DSP. Enabling the check box for the EQ, even if the sliders are at 0.0, will cause the input signal to be processed by the DSP and will therefore decrease sound quality because of inevitable approximation errors when operating a tranformation from the time domain to the frequency domain.

The Mixer

There are multiple volume adjustments for different inputs and outputs on the system. The master volume affects all of these settings. If a single source is too loud or distorted it should be turned down using the appropriate mixer. The default and recommended value is 50% for all sources, which actually equates to a 0 dB amplification, while a 100% value causes a 6 dB amplification.

Dolby Digital Bitstream Out

This setting controls the DD sound decoder.

DTS Bitstream Out

This setting is the same as Dolby Digital Bitstream Out, only with DTS sound instead.

[edit] Current X-Fi line-up

X-Fi Elite Pro
X-Fi Fatal1ty (also known as: X-Fi Fatal1ty FPS / X-Fi Fatal1ty Edition / X-Fi Platinum Fatal1ty Champion)
X-Fi XtremeGamer Fatal1ty Pro Series (added in October 2006)
X-Fi Platinum
X-Fi XtremeMusic
X-Fi XtremeGamer (added in October 2006)
X-Fi Xtreme Audio (added in October 2006)
X-Fi Digital Audio (added in October 2006)