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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DerekWilson - Wednesday, August 31, 2005 - link
we'll try itReflex - Wednesday, August 31, 2005 - link
Well said, SDA. And yes, I also appreciate the maturity of AT editors. I do feel a disclaimer needs to be added to the article, that said they could easily have overreacted(as THG editors tend to).Reflex - Wednesday, August 31, 2005 - link
Derek - The concern I have is that your review, as it stands, is a ringing endorsement for a product in a market you do not fully understand. The users who rely upon Anandtech as their only source for this type of reccomendation are likely to purchase something like this, even though there are a wide variety of competitive solutions out there for a quarter of the price. I feel you should at the least post a disclaimer that your audio review process is a work in progress and make it very clear that you do not fully understand the market that the X-Fi is being marketed to, nor have adequate experience with competitive audio solutions.More damaging, from my perspective, is the fact that Creative has not pledged to support future standards or alternative OS's. On a $400 product it should not be obsolete in the 14 months between today and the release of Windows Vista. You need to at the least get a solid statement on whether or not the X-Fi will support the new audio standard natively, or if they intend to only support it in legacy interfaces. This is a sound card, not a video card, a user should not expect to have to upgrade in a little over a year.
PenGun - Tuesday, August 30, 2005 - link
Try an M-Audio Audiophile 24/96. I used to run a TB Pinnacle which seriously kicked ass on all creative products including all the audigys I ran into.The M-Audio Audiphile is better. A very sweet card pushing the limits of what is possible with a switching power supply.
After what creative did to Carmack there is no way I will ever buy their stuff again. As they continually make crap as far as I can tell, it's no problem.
My card goes directly to Kimber braided, RCAs on the Audiophile, then to my Sonic Frontier's factory modded (mostly voltage control cicuits) SFL-1 Signiture preamp. From there we go to a pair of SFM-75 monoblocks, again not stock, running Svetlyna 6550B power tubes. That goes, biwired, on Tara Time and Space cables to a pair of BMW Matrix 1 speakers.
I do have a revealing system eh' ;).
PenGun
Eskimooo - Tuesday, August 30, 2005 - link
would that be any good for games, too?PenGun - Tuesday, August 30, 2005 - link
It's pretty awesome actually. No hardware acceleration of course, but it's not a problem on my new Athy 64.PenGun
Eskimooo - Wednesday, August 31, 2005 - link
hold on, no non-Cretaive card does EAX 3,4,5 at present...So it may sound awesome but you do not get max out of the gameDoes this card produce surround sound over the headphones? Call it gimmicks, but I'd be much interested in that. For practical space reasons and occasional nite gaming.
PenGun - Wednesday, August 31, 2005 - link
Sound is what I care about. Positional audio in games is really not much more use than stereo. We can meet somewhere and see who walks away ... ;). Nexuiz is open source Quake,Quake2,Quake3 on steroids. Fun is back in deathmatch.I wonder why my account disapeared, I just recreated it but that is kinda strange.
PenGun
blckgrffn - Tuesday, August 30, 2005 - link
Where is it, dammit?!?!I guess I was unaware that the Intel solution had this ability. It may make sense to get a board featuring this ability to hook it up to my receiver, I can't believe creative can't figure out that we would really like to hook up a high quality card via a digital cable...
segagenesis - Tuesday, August 30, 2005 - link
This is exactly why I got the HDA X-Mystique 7.1. I believe it is a licensing issue that Creative does not wish to bother with, or does not care to bother with. It's not a perfect card (minor control panel issues) but it does exactly what I want, and has great audio qualiy.It may not be as super ultra quality as this new card, but I would rather enjoy the fact it has DD 5.1 Live. The review kind of says it anyways, he mentions that using existing hardware compared... *ahem* this new "extreme" sound card doesnt really make an audible difference. If your onboard 5.1 sounds ok to you, why even bother upgrading?
One thing that I find troubling is that game performance is slightly less with the X-Fi and considering Creative's lack of promtness with driver updates I would feel worried about optimizations.
The last Creative card I owned was a SBLive! 5.1 and I don't really miss the brand.