Philips PSC724 Ultimate Edge

Rightmark Audio Analyzer 5.3 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.

Philips - 16bit/48kHz	Philips - 24bit/48kHz	Philips - 24bit/96kHz	Philips - 24bit/192kHz

SB Audigy 2 ZS - 16bit/48kHz	SB Audigy 2 ZS - 24bit/48kHz	SB Audigy 2 ZS - 24bit/96kHz

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.

Philips - 16bit/48kHz	Philips - 24bit/48kHz	Philips - 24bit/96kHz	Philips - 24bit/192kHz

SB Audigy 2 ZS - 16bit/48kHz	SB Audigy 2 ZS - 24bit/48kHz	SB Audigy 2 ZS - 24bit/96kHz

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.

Philips - 16bit/48kHz	Philips - 24bit/48kHz	Philips - 24bit/96kHz	Philips - 24bit/192kHz
SB Audigy 2 ZS - 16bit/48kHz	SB Audigy 2 ZS - 24bit/48kHz	SB Audigy 2 ZS - 24bit/96kHz