Soundblaster X-Fi XtremeMusic

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RMAA continued

Rightmark Audio Analyzer 5.5 Continued
The Numbers Continue...

THD + Noise (at -3 dB FS):

Total Harmonic Distortion is defined as "a signal, the ratio of (a) the sum of the powers of all harmonic frequencies above the fundamental frequency to (b) the power of the fundamental frequency."  When a soundcard processes a signal, the output is an amplified version of the input signal plus any distortion that is created during the processes.  Even though some signal processors may add very little distortion to the output, there is always some present.  In the case of the numbers below, the closer the value is to zero, the less distortion and the more accurate the reproduced signal is.

     

Soundblaster X-Fi XtremeMusic - THD + Noise (-3dB FS)

Test Setting

24bit/96kHz

  Left / Right
THD, % 0.0019, 0.0020
THD + Noise, % 0.0060, 0.0063
THD + Noise(A-weighted), % 0.0027, 0.0028

 

Integrated Intel High Definition - THD + Noise (-3dB FS)

Test Setting

24bit/96kHz

  Left / Right
THD, % 0.0270, 0.1102
THD + Noise, % 2.0282, 2.9231
THD + Noise(A-weighted), % 0.0379, 0.1445

As expected, the X-Fi XtremeMusic walks away relatively uncontested. Although the Intel solution did relatively well, the X-Fi trounced its scores by a sizeable margin. Overall, the X-Fi has less distortion and produces a much more accurate signal.


Intermodulation Distortion:

IMD is the "nonlinear distortion in a system or transducer, characterised by the appearance in the output of frequencies equal to the sums and differences of integral multiples of the two or more component frequencies present in the input waveform." Basically this means that when two signals at difference frequencies are produced simultaneously, additional signals at other frequencies and amplitudes are created.  These new signals are found at the sum, and difference, of the two original frequencies.

So, if the original signals where 2 kHz and 8 kHz, IMD would create two additional signals at 10 kHz ( 2 + 8 = 10) and 6 kHz (8 – 2 = 6).  Of course, it would be too simple of it ended there.  Each of these new signals caused by IMD is able to cascade off of each other and create more IMD of their own. Obviously, this means many other frequencies will be created, thus causing a huge mess of distortion.

Just like the other tests, a lower value signifies less amounts of IMD, thus a better overall sound quality.

     

Soundblaster X-Fi XtremeMusic - Intermodulation Distortion

Test Setting

24bit/96kHz

  Response
IMD + Noise, % 0.0075, 0.0078
IMD + Noise (A-weighted), % 0.0031, 0.0032

 

Integrated Intel High Definition - Intermodulation Distortion

Test Setting

24bit/96kHz

  Response
IMD + Noise, % 0.2733, 1.2742
IMD + Noise (A-weighted), % 0.0815, 0.3108

As was the case with THD, the Creative X-Fi XtremeMusic dominated this test. Here, the card again saw a profound advantage with a much cleaner signal as a result. Although lesser quality speakers might hide some of the inherent noise on the Intel solution, a high end pair of speakers will clearly illustrate the limitations the integrated solution has compared to the X-Fi XtremeMusic.


Stereo Crosstalk:

Stereo Crosstalk is when "undesired signals or sounds, as of voices, in a telephone or other communications device as a result of coupling between transmission circuits."  In the case of the soundcard, it is when a signal that is meant for the left channel, ends up being partially outputted on the right (or vice versa).  Subsequently, this disrupts the stereo imaging and overall sound field.  Obviously in this case, the less crosstalk (lower the value) the better.

     

Soundblaster X-Fi XtremeMusic - Stereo Crosstalk

Test Setting

24bit/96kHz

  L->R / R->L
Crosstalk at 100Hz, dB -92, -91
Crosstalk at 1kHz, dB -95, -95
Crosstalk at 10kHz, dB -83, -91

 

Integrated Intel High Definition - Stereo Crosstalk

Test Setting

24bit/96kHz

  L->R / R->L
Crosstalk at 100Hz, dB -47, -38
Crosstalk at 1kHz, dB -67, -58
Crosstalk at 10kHz, dB -74, -62

Somewhat curiously, we see the Intel solution emerging as the victor with far less Stereo Crosstalk. The standard audio patch cable likely didn't aid the card in this test. Do yourselves a favor and ensure you use high-quality cables to take this variable out of the picture altogether and ensure your audio quality is as high as possible. Surprisingly enough, no audible artifacts from this apparent crosstalk appeared during listening tests. This is yet another example of a time when numbers help, but a personal test is necessary to formulate a final decision.

Tags:  music, X-Fi, sound, Xtreme, XT, eme

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