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 "", a technology that claims to improve the clarity of digital music through digital analysis (supported by all X-Fi models, including the Xtreme Audio and X-Mod). 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. Since its release X-Fi has caused several unsolved problems with sound glitches on various motherboards. Creative Labs states that the primary function of the is to "restore portions of the sound which were lost during compression". The "compression" that is meant here is not the digital file-size reduction achieved by digital audio data compression technologies like for example mp3. Rather, the idea is to reverse the effects of dynamic range compression, an analog technique that was and is used during the production of most 1990s and newer Audio CDs (with the exception of some classical music recordings) to make them sound louder at the same volume level setting, as it was found that subjectively louder CDs get more airplay and sell better. To achieve this loudness without introducing strong distortion, points in the signal where the volume reaches a maximum are compressed (which means in this case: reduced in volume), then the whole signal is multiplied by a factor so that the maximum volume is reached again. After this, the music as a whole is louder than it was before, but the maximum volume points (mostly transients) are not as pronounced as they were before. Since this whole process is done before the final Audio CD is recorded, its effect is equally present in uncompressed audio files created from such a CD, in lossless compressed audio made from the CD, as well as in lossy compressed audio from that same CD. Transients are typically found in percussive sounds, in plosive consonants of voice recordings, and during the first few milliseconds (the so-called attack phase) of non-percussive