New Features, Possibilities, and Modes

The main new audio processing features of the X-Fi line are the 24-bit Crystallizer and CMSS-3D. These features, as well as the onboard RAM and the three modes of operation (gaming, entertainment, and creation) will be explored in this section. We know what each of these features is and the basic principles on which they operate. While we could make a much more thorough analysis of the quality of these features, if we had some actual math to go on, it is understandable that Creative would want to protect their investment by keeping the intimate details of the architecture private. What we do know should be enough to go on for now.

The 24-bit Crystallizer

The 24-bit Crystallizer takes 16-bit audio and tries to add dynamic range to the audio signal. If we were to convert our 16-bit audio stream to 24-bits, we could essentially do so by adding 8 zeros to the least significant end of each sample. It becomes clear that the highest value that a sample can take on is much less than the highest value possible with 24-bit audio. Likewise, on the low end, the audio stream isn't capable of representing values between zero and 256. The basis of the 24-bit Crystallizer is to fill in these least significant bits with meaningful data and thus, expand the dynamic range of the audio. What, exactly, is meaningful data in the least significant bits? We're glad that you asked.

Audio engineers are big fans of compression. Applying compression to a sound decreases the dynamic range of a sound in order to preserve the loudest and quietest parts without clipping or burying the subtleties in noise. This is very necessary to make good use of 16-bit audio, as things like whispering over a snare hit are not easily representable otherwise. Knowing the basic manner in which audio engineers go about applying effects to sounds, Creative can try to reverse-engineer the process to add more data where it seems necessary.

Details on the technique are fuzzy at best, but we do have some information. The algorithm doesn't simply expand the audio signal; it looks for recognizable patterns in frequency and time and applies algorithms that fill in the data where necessary. For instance, the X-Fi hardware is able to detect something like a kick drum hit and use the sound and proportionally weighted, transient, low-frequency data to boost the impact of the event.

The algorithms focus on the energy flux in different frequency bands in order to localize the impact of the effect. This means that things like snare and symbol hits, the plucking of strings on an acoustic guitar, the slapping of a string on a bass, and gunshots in games should all become more distinct. Each sound will be enhanced according to its energy flux, frequency, and waveform. Creative states that this can even help clean up the high end on MP3 encoded files. What this doesn't enhance quite as well are quiet subtleties in the audio signal.

CMSS-3D

For 5.1 sources played on headphones with CMSS-3D, Creative uses HRTF (Head Related Transfer Functions) to virtualize the position of each audio channel around the listener. This technique is augmented with simulated environmental reflections, which attempt to improve the externalization of sound to the listener. These environmental effects are more subtle than the Dolby Headphone effects and are meant to convey a listening environment that matches the recording rather than one that fits the room in which the listener is sitting.

When enabled for 3D virtualization with two speakers, the methods used are similar to that of the headphone implementation. Rather than adding environmental reflections, this CMSS-3D mode includes a cross-talk canceller to make sure that signals from one speaker are not destructively combined with signals from the other at the listening sweet spot. Unfortunately, there is still a sweet spot for listening to audio in this mode, but settings like speaker angle are easily adjustable.

Probably the best use for CMSS-3D has nothing to do with two speaker setups. Getting the most out of a 7.1 channel audio setup is much easier with CMSS-3D. We still don't recommend using CMSS-3D for stereo sources, but for listening to 5.1 audio, CMSS-3D will do a good job of fitting the 5.1 sound to 8 channels. For creating a multi-channel environment with a two-channel source (if we absolutely must), our favorite solution is still Sonic Focus' implementation on Intel hardware. It's a shame that they won't open up their software for other hardware.

64MB onboard RAM

The top two models in the X-Fi series feature 64MB of SDRAM on the sound card itself. This feature is called X-RAM, but that isn't a technical term. X-RAM is a marketing name given to maintain the X- moniker of the card itself. This RAM is supposedly included to enhance the performance of games. Until games are written to take advantage of this feature, we will have to simply accept the possibility for performance improvement.

Creative has shown us some numbers that they have run using UT2K4 and a special patch that allows for playing over 100 voices at a time (currently only 30 are supported in the game), as well as uploading uncompressed sound files to the onboard memory. The numbers show a pretty big performance improvement when X-RAM is enabled in this case. Unfortunately, we don't know how real world this test is. Without having the patch to test ourselves, we can't really know what's going on. If we are more than tripling the number of concurrent voices, we would hope to see some sort of quality improvement as well. A performance improvement for a feature that isn't necessary is a useless test.

We really need to spend more time with games that currently support X-Fi to see if we can find a case where the extra RAM affects performance. Our best guess is that we won't see real impact from this feature until developers realize that they can target the Creative solution to deliver a higher quality audio experience. Playing audio with higher sample rates, adding voices, using uncompressed audio to save CPU overhead, and freeing system RAM for other uses should be quite attractive to audio designers.

3 Modes of Operation

The final major feature is the inclusion of three distinct modes of operation. This feature is necessary because of the complexity and flexibility of the Audio Ring architecture. Tradeoffs are necessary for every type of audio application, but a configuration that can switch between modes depending on the task at hand could be a major development in the "one size fits all" audio department. These are the features of the different modes.

Gaming Entertainment Creation
Video Game Frame-Rate: YES NO NO
Hardware 3D Audio Processing: YES NO OPTIONAL
Environmental Effects: YES OPTIONAL OPTIONAL
High-Resolution Audio Playback: NO YES YES
Audio Enhancement Processing: NO YES OPTIONAL
2-Channel to Multi-Channel Up-Mix: OPTIONAL YES NO
Multi-Channel Audio Recording: NO NO YES
Hardware MIDI Playback: NO OPTIONAL YES
Hardware Effects: YES YES OPTIONAL
Sample-Synchronized Record and Playback: NO NO YES
Low Audio-Streaming Latency: NO NO YES
Bit-Accurate Audio Capable: NO OPTIONAL YES

Professional recording requires low latency, especially when using ASIO drivers. Therefore, it makes sense that Creative would implement a mode targeted at getting audio in and out of the Audio Ring as fast as possible. Effects possible in Creation mode are limited to those that can be performed very quickly, and audio comes through the chain as unmessed as possible. Less than 2ms latencies are possible in this mode. Again, our only complaint with the Elite Pro as a professional solution is its lack of balanced I/O.

Entertainment mode focuses on the music and movie experience. Options for enhancing both stereo and surround sources are pushed to the foreground and features like the 24-bit Crystallizer and CMSS-3D will likely be heavily used in this mode.

Gaming mode is optimized for creating a multitude of hardware accelerated voices and processing them to create the best real-time 3D that audio developers can throw at it. With up to 127 3D + EAX voices, extremely complex effects are possible. Under this mode, X-RAM can be used to assist in the storage and playback of audio files.

X-Fi Processing Elements: The Quartet DSP SoundBlaster X-Fi Elite Pro
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  • SDA - Tuesday, August 30, 2005 - link

    >>Why do you post opinion like that and give no example? What is the point? >>
    Well, gee, I don't know. Why do you post your own opinion? Because we both like to post our opinions, of course. Everyone here does, else their posts wouldn't be there.

    I agree that it's only fair to provide examples, so I have done so in my post. Beyond that, some general rules before buying ANYTHING:

    - Determine what measurements and features you should be looking for. For example, with a CPU or GPU, you'd know you'd want to look for benchmarks in applications that you find yourself using most often, and what features you wanted or needed for those applications (SSE3? Multiple cores?). With a PSU, you would look for power quality (as determined by rail sag under load, AC ripple on all rails under load, etc.), ability to supply a given amount of power over a long period, whatever features you needed (modular cables? no fan?), component quality, and preferably a large amount of samples (there is often a great difference in quality from PSU to PSU from the same manufacturer).

    - See if you can obtain some background knowledge in that field. It's a pain, I know, but it can come in really handy if you don't know what sources to trust or what features to look for. For power supplies, that means getting some basic power-specific EE knowledge (or asking an EE, heh); for CPUs or GPUs, that means trying to understand a little about how these processors work, what specific attributes are valuable in the applications you use, and how performance can be affected by the rest of the system.

    - Find resources that you trust. You can identify these by whether or not the reviews or analyses in these resources take into account relevant measurements and features, and by how knowledgeable the reviewer seems in a specific area. A video card review that only does AquaMark and 3DMark should not be trusted (and the site or person that does it should be regarded with some suspicion in that field), and neither should a power supply review where the reviewer does not once mention ripple or do anything more than check the rails under light load with a Windows utility.

    - Consider bias. This is not relevant at AT, where I at least trust the editors, but it is very important with some guy that spent a big chunk of money buying something. Of course someone who spent $500 on the latest and greatest processor is going to say that they like it, unless something is horribly wrong. How often do you hear people say that they think their stereos sound bad, that their computers are overpriced, that the PSU that they bought doesn't use the components they would expect at its price point? Now, I grant you, rational people do buy things BECAUSE they feel they are good choices, but there is almost always a significant degree of personal bias with some personal item.
    (bias is also relevant when considering smaller or less trustworthy sites that may rely on manufacturers' goodwill, including but not limited to THG.)


    A little long, I know, but maybe what little I know can help you with future purchases. If not, you don't have to read it, heh.
  • Eskimooo - Wednesday, August 31, 2005 - link

    thanks for that. Much appreciated. Well, I did quite a research and virtually all reviews I came across including digit-life appreciate technology behind X-Fi. Most reviewers like even this much doubted Crystallizer feature, which is not obligatory and adjustable anyway.I do not believe Creative is so powerfull to exercise pressure on all the reviewers. So if both RMAA etc tests and subjective tests give positive results this card is probobly good and I think I am going to buy it
  • Eskimooo - Tuesday, August 30, 2005 - link

    previous one posted to early, sorry. So my final question to all who listened to music using the X-Fi card and can compare it to other sound cards: Is there anything that would give more better features at the same quality level and at the same price? Please do not reply on Audigy or Live because X-Fi is a completely different card.
  • DerekWilson - Tuesday, August 30, 2005 - link

    It depends on what you are looking for, but in most cases I will have to disagree with you.

    The Gina 3G sells for $350 and does not off the quality of the X-Fi Elite Pro. Features include hardware 3D audio buffers, filters, and effects. Again Pro cards fall short (especially for gaming).

    In fact, the only thing that I would give as an advantage of similarly priced professional audio solutions is balanced audio. This is a big advantage if the user intends to setup a completely balanced audio chain.

    If I had to guess at a product that would best the X-Fi in terms of quality, I would have to point to the LynxTWO-B ... For which you would easily spend more than twice what the X-Fi Elite Pro costs. If you know of a pro card that you feel fits your claim, please point it out to us and we will do a comparison.

    From what we have seen, your prescott/athlon64 comparison doesn't make much sense. If you take away the non-pro qualifier, we would still maintain that the X-Fi Elite Pro is the best sound card for any application at it's price point (unless you need balanced I/O). If you include no upper limit on price, then we will have to wait for our LynxTwo comparison before we shoot our mouths off too much.

    So to recap, pro audio cards at the same price point or below offer fewer features, equivalent or lower sound quality, and similar recording capabilities (with the exception of balanced I/O).
  • SDA - Tuesday, August 30, 2005 - link

    >>The Gina 3G sells for $350 and does not off the quality of the X-Fi Elite Pro. Features include hardware 3D audio buffers, filters, and effects. Again Pro cards fall short (especially for gaming). >>
    I never said anything about gaming, unless you're interested in recording gaming sessions. Anyway, you're relying on a logical fallacy-- specifically, a hasty generalization. More specifically, that the Gina 3G (a small sample) is representative of all pro audio cards in its price bracket.


    >>If you know of a pro card that you feel fits your claim, please point it out to us and we will do a comparison. >>
    Well, the E-MU 1212m is a rather capable card at half that price. The 1820 and 1820m are also capable pro cards. (Yes, I'm aware what E-MU is. The issue is capability for the price, not who owns what.) The Delta 1010LT is also an option, I guess, though it's a little dated now. There are also external options... Edirol equipment was fairly popular here last I checked (prefer separates, so I'm not entirely up-to-date). You're welcome to do your own research, of course-- that would be a good idea if you're going to make statements about what's the best.


    >>From what we have seen, your prescott/athlon64 comparison doesn't make much sense. If you take away the non-pro qualifier, we would still maintain that the X-Fi Elite Pro is the best sound card for any application at it's price point (unless you need balanced I/O). If you include no upper limit on price, then we will have to wait for our LynxTwo comparison before we shoot our mouths off too much.

    So to recap, pro audio cards at the same price point or below offer fewer features, equivalent or lower sound quality, and similar recording capabilities (with the exception of balanced I/O).>>
    The comparison was solely to illustrate the issue of specialized comparisons. If you are willing to remove the "non-pro" qualifier, it is irrelevant.

    I appreciate that the fine folks at AnandTech often have experience with as many as three or four different sound cards, but I must ask: exactly how many pro sound cards have you tested and reviewed? I don't mean "read the specs of", I don't even mean "measured the noise floor of", I mean given a full, comprehensive test. I sincerely doubt it is a very high number, and that you have and are utilizing the proper measurement equipment (and again, simple audio quality measurements say nothing but that everything out there today has obscenely good measurements).

    Why do I doubt that? Well, ffs, you didn't even recognize the "24-bit Crystallizer" for what it was, relying instead on Creative's description that it clears up the high end and adds dynamic range. Someone who can't recognize a crude equalization's effect on the sound and who then regards said equalizer as a noteworthy feature is not someone I am inclined to trust for statements about professional audio.

    If you're curious now about the Crystallizer, you might want to read Digit-Life's significantly better review, linked below.
    http://www.digit-life.com/articles2/multimedia/cre...">http://www.digit-life.com/articles2/multimedia/cre...
  • yacoub - Wednesday, August 31, 2005 - link

    "I appreciate that the fine folks at AnandTech often have experience with as many as three or four different sound cards, but I must ask: exactly how many pro sound cards have you tested and reviewed? I don't mean "read the specs of", I don't even mean "measured the noise floor of", I mean given a full, comprehensive test. I sincerely doubt it is a very high number, and that you have and are utilizing the proper measurement equipment (and again, simple audio quality measurements say nothing but that everything out there today has obscenely good measurements).

    Why do I doubt that? Well, ffs, you didn't even recognize the "24-bit Crystallizer" for what it was, relying instead on Creative's description that it clears up the high end and adds dynamic range. Someone who can't recognize a crude equalization's effect on the sound and who then regards said equalizer as a noteworthy feature is not someone I am inclined to trust for statements about professional audio. "

    Well this is what happens when you have a PC hardware review site in the day and age where the hardware is running out of 'hot new features' and starting to overlap with professional grade equipment in order to justify the pricing.

    It's also what happens when you get a review site reaching out into random other areas like digital cameras - realms where there are other sites that exist solely to do such reviews and will obviously do them to a much finer degree. As you get into the realm of professional audio products with the features of PC hardware audio products, it necessitates one of two things: Delving into the field of pro audio equipment to a large degree, or not making comparisons to items in a field one isn't highly knowledgeable about. :)
  • yacoub - Wednesday, August 31, 2005 - link

    Ah, I see you say as much here:

    "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. "

    Very well put!
  • DerekWilson - Wednesday, August 31, 2005 - link

    We've played with a few different cards extensively, in cluding the TerraTec EWS88 MT the M-Audio Delta 1010 and the EMU 1212 ... We didn't run any RMAA tests on them, as they were used for listening and recording. From our experience, I can say I'd rather have the X-Fi Elite Pro for a non-balanced setup. Currently I have an external ADC for converting balanced line-ins to ADAT and run digital audio to the computer and I use the Gina 3G for recording the ADAT signal.

    Regaurdless of our experience, we haven't done indepth electrical analysis of these parts yet. It is our intention to test other consumer, semi-pro and pro cards and compare them. We drew our assessment of the X-Fi from our experience with hardware and the in-depth tests we have done so far.

    As far as the Crystallizer goes, we are talking about more than one effect if Digit-Life is correct. Yes, there's equalization, but that's not all. I wasn't expecting multiband compression to be added which (as digit-life points out) decreases the dynamic range of the original signal. We will certainly be speaking with Creative about this (there are other things that could be going on that an RMAA test doesn't determine), and if our analysis leads us to the same conclusion we will certainly have some things to say about it. We certainly noticed the general increase in dB level though ... If I didn't mention it, when comparing crystallizer audio with unmodified audio we decreased the volume to match.

    On top of that, the word noteworthy carries a positive connotation. If you mean only to say that we noted the Crystallizer as a feature and tested it, that's fine. Beyond that, our assessment was that the crystallizer had limited application to some audio sources that were already subpar. I would say we were not wrong.

    At the same time, we are still finding our way in PC audio. We recognize we have some room for improvement and appreciate any direction and help we can get. We will expand our coverage to include indepth signal analysis on features like the Crystallizer. There are difficulties in going down this route, and it is hard to correctly talk about the value of psychoacoustic functions or environmental effects from such analysis. We haven't gone there yet because it is like opening a can of worms. Any suggestions are welcome.

    Thanks very much for taking the time to bring all of these issues to our attention.

    Derek Wilson
  • SDA - Wednesday, August 31, 2005 - link

    Why, jooc, would you rather have the Elite Pro? Just what listening equipment are you using (I'd really like to know this part), and what tests have you performed with them (other than introductory spec measurement)?

    Noteworthy does carry positive connotations, but then the fact that your review sees it as a feature that can be useful for some does mean to me that you've classified it as a noteworthy feature when, in reality, it is utterly useless (anything that can benefit from it can benefit from a better, simpler software EQ that you can carry with you from card to card).

    I tend to agree with Reflex here. I understand and appreciate that you guys are trying, and you'll notice I haven't made any stupid accusations about bias, but the fact is that this is an unqualified endorsement. If you're still finding your way in PC audio, you should be a little more cautious about making sweeping general statements.
  • DerekWilson - Wednesday, August 31, 2005 - link

    I would rather have an Elite Pro because I also like to play games and movies as well as record and listen to music. I do to perfer my external ADC for recording, and would probably rely on it instead of the soundcard itself.

    For listening, I generally stick with my Sony MDR-7509 headset. I also have the Sennheiser HD580 that I use to audition sound hardware. The reason I stick with the Sony gear for general listening is due to my environment. I can turn everything off when I need to do a noise test or listen closely to something, but the lab with all the computers and workstations running is not a quiet environment. I realize that open air headests will reproduce (especially) the low end in a more appropraite manner, so I do listen with them, but I know the sound a little better on the MDR-7509s as I've been using them for a long time.

    I am planning on picking up the HD650 as I've heard great things about them.

    The tests I've performed with them include recording and editing audio on them. I've used each of the solutions I mentioned in my home rig before I moved to lightpipe. I'm definitely not saying they don't get the job done well. And if that's all you want a sound card for, then I'd certainly go with one of those solutions over the X-Fi. Likewise, if all you are doing is stereo audio listening then one of the other solutions is still a better choice.

    The advantage of the X-Fi (and I'm sorry if I didn't make this clear in the article) is that it is capable of high quality recording, high quality playback, EAX 2+ with 127 voices, has lots of analog and digital I/O, and generally meets any requirement anyone could have from a consumer or semi-pro sound card (except, again, balanced I/O). But $400 is still too much to pay for this solutioin.

    Doing something like a double blind subjective study on audio is difficult. People that don't know how to listen won't be any help because even if they hear a difference they won't know how to describe it very well. People who do know what they are talking about are hard to come by in volume. Don't get me wrong, we'd love to do something like this. But we just don't have any idea how to work out the logistics. Suggestions are welcome.

    Also, I appreciate the suggestion to avoid general statements about the goodness of something. It is a good suggestion even in cases where we know everything about everything in detail. There are always surprises and erring on the side of caution is the best way to go. We will be more careful in the future.

    Derek Wilson

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