X-fi SRC digitally attenuates, RMAA results shown

tschanrm · Jul 28, 2006, 02:06 AM

Here's some in depth RMAA results. This is with a clean install of the latest X-fi drivers. Recording was done with a Yamaha DP-U50 soundcard, using X-fi's audio creation mode. It appears that Audio Creation (not bitperfect), Game Mode, and Entertainment mode give the same results in 48khz and 44-->48khz.

*Side note: at 16 bit, X-fi's resampling algorithm is near lossless in both bitperfect and non-bitperfect mode, so I did not post results.

24 bit, 48 khz native:

Not Bitperfect mode
Noise - 112 dBA
Dynamic Range -112 dBA
THD - .0001 %
IMD - .0007 %
Crosstalk - 112 dB

Bitperfect mode
Noise -145 dBA
Dynamic Range -133 dBA
THD - .0000 %
IMD - .0002 %
Crosstalk - 145 dB

24 bit, 44khz resampled to 48khz:

Not Bitperfect mode
Noise - 112 dBA
Dynamic Range -112 dBA
THD - .0001 %
IMD - .0007 %
Crosstalk - 113 dB

Bitperfect mode
Noise -141 dBA
Dynamic Range -132 dBA
THD - .0001 %
IMD - .0002 %
Crosstalk - 140 dB

Looking at the visual graphs, it becomes obvious that X-fi digitally attenuates in non bitperfect mode. Take a look for yourself, green and white overlap identically on the line peaks:

24 bit, 44khz-->48khz :

IMD Graphs (click to enlarge):

THD Graphs (click to enlarge):

I posted this over at Head-Fi, but did not get really get any response.

Anyway, can somebody else please confirm my results? I know a lot of people on this forum have an X-fi, and performing this quick RMAA test could show whether or not the X-fi truly digitally attenuates when not in bitperfect mode. For now I would say stick to bitperfect mode at all times unless you are doing gaming.

Jul 28, 2006, 02:06 AM	#1
tschanrm DriverHeaven Newbie Join Date: Mar 2006 Posts: 5 Rep Power: 0	X-fi SRC digitally attenuates, RMAA results shown Here's some in depth RMAA results. This is with a clean install of the latest X-fi drivers. Recording was done with a Yamaha DP-U50 soundcard, using X-fi's audio creation mode. It appears that Audio Creation (not bitperfect), Game Mode, and Entertainment mode give the same results in 48khz and 44-->48khz. *Side note: at 16 bit, X-fi's resampling algorithm is near lossless in both bitperfect and non-bitperfect mode, so I did not post results. 24 bit, 48 khz native: Not Bitperfect mode Noise - 112 dBA Dynamic Range -112 dBA THD - .0001 % IMD - .0007 % Crosstalk - 112 dB Bitperfect mode Noise -145 dBA Dynamic Range -133 dBA THD - .0000 % IMD - .0002 % Crosstalk - 145 dB 24 bit, 44khz resampled to 48khz: Not Bitperfect mode Noise - 112 dBA Dynamic Range -112 dBA THD - .0001 % IMD - .0007 % Crosstalk - 113 dB Bitperfect mode Noise -141 dBA Dynamic Range -132 dBA THD - .0001 % IMD - .0002 % Crosstalk - 140 dB Looking at the visual graphs, it becomes obvious that X-fi digitally attenuates in non bitperfect mode. Take a look for yourself, green and white overlap identically on the line peaks: 24 bit, 44khz-->48khz : IMD Graphs (click to enlarge): THD Graphs (click to enlarge): I posted this over at Head-Fi, but did not get really get any response. Anyway, can somebody else please confirm my results? I know a lot of people on this forum have an X-fi, and performing this quick RMAA test could show whether or not the X-fi truly digitally attenuates when not in bitperfect mode. For now I would say stick to bitperfect mode at all times unless you are doing gaming.