Greetings to Rob and the list!
I've been lurking for a while but now I'd like some advice. For the lack of money for a 24/96 card, I just bought a Hercules (ex Guillemot) Game Theatre XP 6.1 card, which features the Crystal CS4630 DSP with 18-bit ADC and 20-bit DAC. (It's the same chip as the Videologic Sonic Fury, and the Turtle Beach Santacruz)
Using Mad I can listen to music when I set Mad's resolution in both 24 and 32 bits, when the output plugin is either wave out (Winamp critical update installed). With the directx output plug, I get white noise in both 24 and 32 bits.
Question 1 is: Is there a way to certify that the resulting sound is taking advantage of the 20 bit resolution of the card and that it's not just a dithered to 16 bits sound ? (provided of course that the card's drivers do actually support these 20 bits of the ADC...)
Question 2 is: Does anybody know of any DSP music enhancer Winamp plug that would support more than 16 bits ? The ones I tried did not work. I know some of you have 24/96 cards and so I expect you might use DSP plugins.
Thanks in advance for any tips!
By the way, and for your information, Terratec will soon produce a new budget card, the DMX 6fire LT priced below 150 euros. It's a full 5.1 channel 24/96 card (all channels being 5.1) with the same specs as the existing 6fire but without the breakout box - a definite best buy. Amazon.de and computeruniverse.com already offer it as a preorder. Of course i'm not in any way affiliated to these companies, it's just that this will be my next card - cheaper than any 24/96 stereo channel card, even Terratec's.
Needless to say, since the time I left the list some months ago, I have recommended Mad to some 100+ people who use it daily. Moreover, Mad is used some 10 hours per day on my PC... Long live MAD !
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Unorthodox Behaviour wrote:
Greetings to Rob and the list!
I've been lurking for a while but now I'd like some advice. For the lack of money for a 24/96 card, I just bought a Hercules (ex Guillemot) Game Theatre XP 6.1 card, which features the Crystal CS4630 DSP with 18-bit ADC and 20-bit DAC. (It's the same chip as the Videologic Sonic Fury, and the Turtle Beach Santacruz)
...
Question 1 is: Is there a way to certify that the resulting sound is taking advantage of the 20 bit resolution of the card and that it's not just a dithered to 16 bits sound ? (provided of course that the card's drivers do actually support these 20 bits of the ADC...)
Unfortunately, if it's a 20-bit DAC and you feed it 24 bits of data, the 4 least signifigant bits just get chopped off which is not desirable. I would venture to guess that 16 bits with MAD's dithering would be better than 24 bits with the last 4 being ignored.
Ian
Ian Scott ian@polpo.org wrote:
Unfortunately, if it's a 20-bit DAC and you feed it 24 bits of data, the 4 least signifigant bits just get chopped off which is not desirable. I would venture to guess that 16 bits with MAD's dithering would be better than 24 bits with the last 4 being ignored.
A slightly strange thing to venture....
Truncating 24bit data after 20 bits would give an effective 19.5 bits, _across the entire frequency range_.
Dithering is about generating a more accurate average value over a range of samples. For example, alternating between two consecutive 16bit values would give an average half way between them i.e. 17bits effective resolution, but only for signals upto 1/4 of the sampling frequency.
To get an effective 20bit output from 16bit samples + dither, you must limit your signals to 1/32 of the sampling frequency (ie 1.4 kHz for 44.1 kHz sampling frequency).
The maths may be slightly more complex than I have made it out to be, but I think the end result is the same: a true 19.5bit output is likely to far superior to 16bit output + dither for almost all types of music.
Andre --
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Dear Ian,
Thanks for the fast reply !
My limited knowledge of digital electronics allows me to venture that these 20 bits would be better than even correctly dithered 16 bits, because I'll still gain 4 more bits that were previously not accessible with my old 16 bit hardware. In other words, I hope to get 19 accurate bits, and a 20th bit that will be a result of truncation and not dithering. As I see it, this is an improvement over a properly dithered 16th bit. But let's wait and see what the experts will say :)
UB
--- Ian Scott ian@polpo.org wrote:
Unfortunately, if it's a 20-bit DAC and you feed it 24 bits of data, the 4 least signifigant bits just get chopped off which is not desirable. I would venture to guess that 16 bits with MAD's dithering would be better than 24 bits with the last 4 being ignored.
Ian
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Andre -
Ian Scott -
Unorthodox Behaviour