X-Fi and the Elite Pro: SoundBlaster's Return to Greatness
by Derek Wilson on August 30, 2005 11:59 AM EST- Posted in
- Smartphones
- Mobile
X-Fi Processing Elements: Exploring the SRC
Sample rate conversion is one of the causes of poor audio reproduction in current sound cards. So, why make such a big deal out of sample rate conversion on the X-Fi? This time, Creative has implemented an SRC that generates very low noise and distortion, and the Audio Ring allows data that doesn't require sample rate conversion to bypass the step altogether. For the conversion of a 997Hz signal from 44.1kHz to 48kHz, the SRC demonstrated -136dB THD+N and +/- 0.00025dB pass-band ripple. Creative says that this is 300 times the quality of the SRC step in previous generation SoundBlaster products. These excellent results allow data to be passed multiple times through the SRC without any significant distortion of the data, making the SRC a key part in effects processing.Pitch shifting can now easily be done on the SRC. Multitasking the sample rate conversion hardware for effects further allows creative to justify the efforts that they put into its development. One thing that Creative says can be dynamically applied to sound in realtime through the SRC is the Doppler effect. This could allow game designers, for instance, to apply a Doppler effect to all moving sound in a scene relatively easily. Sound synthesis can also use the SRC to change the pitch of a sound easily. The SRC also fits into 3D audio processing.
In pro audio applications, the SRC can be used to avoid the necessity of an external clock for syncing audio signals. Synchronized audio is still possible on X-Fi, but audio from multiple sources can be mixed with very good results using the SRC. As we have said before though, applications that do not require sample rate conversion will be able to bypass the SRC all together.
In order to create such a high quality SRC, Creative created a three-step hybrid filter. First, the sample rate is linearly increased by a factor of 2 using fairly simple math - no complex filters are needed for this step. The next stop along the way to sample rate conversion is a poly-phase FIR filter that up-samples its input to 2*(desired_sample_rate / original_sample_rate). This gives us data with a sample rate that is 4 times the desired sample rate. The final step is to reduce the sample rate by a factor of four (which is also an easy computation). Aside from increasing the quality of the sample rate conversion, increasing the sample rate to 4x the desired final rate also serves as an effective anti-imaging filter. The highest frequency that can be represented in sampled digital audio is half the sample rate (as per Nyquist). Imaging is a "ghost" of the audio signal in the range between the sample rate and half the sample rate. Assisting with anti-imaging is a by-product of the X-Fi SRC.
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NovaPolice - Wednesday, August 31, 2005 - link
Yeah, I'm somewhat curious as to how the crystalizer does in comparison to Qsound's methods, Qsizzle, Qrumble, and Qexpander, which I have enjoyed for a while. Probably the best candidate for comparison would be the envy24(with-some-tricks)-based PSC724 Ultimate Edge. Of course.... that thing only costs 30 bucks at outpost, and philips is kinda bad at releasing drivers.I wish Qsound Labs would create some kind of hardware chip. Some kind of alternative to the various successions to EAX. Their expander kicks ass.
Or it would be nice to see something with Creative's hardware power combined with Qsound's algorithms.
flexy - Tuesday, August 30, 2005 - link
>>>i highly doubt it. Better save your money and invest in better speakers [if not already]..this is really all bunk. ALL they can sell is features and irrelevant addons/gadgets/specs...specs which are only relevant MAYBE for hardcore pro-musicians. But then i dont know any pro-musician who does his recordings on a creative card :)
>>>
Btw, i also highly, highly doubt that for listeining to music/mp3s etc. people will notice a difference (towards the better) with a VERY old AWE32/64 card compared to any of the newest cards out right now. I remember actually that years agomy AWE64 had this certain "punch" to her which i liked...and i cant even necessarely say that for listening to music my current Audigy2 is noticeable "better"...but then this is a long time ago :)
Anyway...leave 'em the fun to sell their products with dumb marketing terms....and as stated elsewhere...hope that the OEM/lower end cards will be much cheaper. (For what it's worth)
Calin - Wednesday, August 31, 2005 - link
I found also that my Creative Sound Blaster 16 (ISA card, with 2x4W amplifier on card) sounded more "musical" (let's say I consider it better sounding) than the newer Audigy 2 gamerCalin
Wellsoul2 - Tuesday, August 30, 2005 - link
I went from SBLIVE to Chaintech VIAEnvy to Audigy 2 ZS.It would be nice to have a card good in games and music.
Subjectively I think the Audigy 2 ZS better with MP3's and games than
the Envy Card.
Also I've found that the software makes a big difference.
Anyone notice that Itunes free player sounds much better than Windows Media Player or
Creative Player? (With any audio Card)
I really liked the ViaEnvy sound but it really won't do games well.
flexy - Tuesday, August 30, 2005 - link
i never use the creative software, neither do i use itunes.If i want to have highest quality sound then i use foobar2000 with kernel streaming or foobar/winamp with direct asio (plugin) output. I dont think there's anything better right now (in terms of player/output/quality)
Parak - Tuesday, August 30, 2005 - link
Seconded, would love to see a matchup of this card versus Envy24 solutions.imaheadcase - Tuesday, August 30, 2005 - link
"Creative informed us that cards should be shipping as of last week, but we still can't find them online or in stores. Even Creative's own site lists the X-Fi line up as pre-order. We will have to check into the availability of these parts as we certainly don't want the recently ATI disease (“paperlaunchitis”) to spread to the rest of the computer industry. "Actully you can order it on creative site, I see you can do it as i type this. Also can purchase it at Best Buy, they have dozens of them on display. There are 3 online retailors that have it listed. Was this artical typed out a week ago or something? lol
I will sum of this card for everyone: Wait a few months, and you can get it for a little over $50 for cheaper one. The high end card are pretty much same as cheaper one, you just get some extra CRAP with it. Pretty much %90 of the stuff on card is useless to the average user. This is essentially a Audigy 5 card...go go marketing from creative :P
HardwareD00d - Wednesday, August 31, 2005 - link
I saw an X-Fi card in Best Buy last week (Phoenix AZ, US) Looked pretty neat and I had just heard of them, so I was surprised to see it on the shelf so soon.missleman - Tuesday, August 30, 2005 - link
All that mumbo jumbo doesn't look like it will have any real use for me.HardwareD00d - Wednesday, August 31, 2005 - link
Tom's Hardware seemed to really like this card. They were much more impressed by the sound than Anand was.http://www.tomshardware.com/consumer/20050818/inde...">http://www.tomshardware.com/consumer/20050818/inde...