I doubt many audiophiles will take this over a good quality external dac.

It's not for audiophiles, it's for movie/htpc enthusiasts.

Thank you for reviewing audio products on silentpcreview, but this time I strongly disagree with your conclusion "Extremely high output level".

A maximum output level of 2Vrms (6dBV) is the standard output level of red-book CD players.

Maybe you have confused nominal levels with maximum levels? The difference between these two levels is called the headroom. It allows for handling signals with a high crest factor (peak to rms ratio) such as music. The nominal consumer output level is -10dBV. Thus the CD-player format allows for 16dB of headroom above the nominal level, which corresponds pretty well with the crest factor of many types of music and speech.

Most professional and semi-professional audio equipment that handles consumer levels (-10dBV nominal) specify their maximum output levels as well. Both the EMU 1616m and the M-Audio Audiophile 192 specifies 6dBV maximum so the Xonar falls in line with these products.

If the Xonar has a maximum output level of 10dBV with a 0dBFS sine wave, then this is only 4dB above the CD player standard, hardly extreme. If you want to put the Xonar in a more positive light you might say that it provides 20dB of headroom above the -10dBV consumer output level standard, and thus allows for signals with a high crest factor to pass through undistorted.

I suggest that you remove the statement about extreme output levels from your conclusion and rewrite the paragraph about audio levels so as not to confuse other readers on this, I admit, confusing subject.

A good reference on all things pro and semi-pro audio:
http://www.rane.com/digi-dic.html
http://www.rane.com/library.html#rnotes

Best regards,
OJG

Is there a comparison with that rmaa test and the onboard sound available on many mbs?




/me shows his total lack of knowledge on audio decoding here...


it did make me want to dl Tusk though, so thanks.
and what you discribed for pink floyd, isn't that just exactly how it was recorded, seperately? that album is tweaked to perfection afaik.

Great card but 200-290$ ?! You can buy very good DAC for that money, or even a nice home cinema amp...

I think there is a mistake in the review. It states that the Xonar is the only way to get protected high resolution audio formats over HDMI on a PC, but the Radeon 48x0 cards can do it as well. As such, no sound card is required at all and the 48x0 cards also do full hardware decoding of the video, and you can use any software you like including Media Player Classic and Vista Media Centre.

For music, get a cheap Via based card with bit-perfect digital output like the sub £10 Chaintech AV-710. Then get an external DAC.

I think the Xonar cards are really only going to be of interest to gamers. If you want full hardware acceleration of 3D sound in games you had to buy a Creative card, with their dodgy bloated drivers and dire support, until Asus came along. I hear it's pretty good for gaming (no pun intended.)

hmm, 250 for xonar, another 100 for hd-dvd blu-ray combo, another 300 (at least!) for case and interior. hmm, ive got ep-35 for 200, a ps3 (remember, it also plays games) for 400. so for 600 i have a fully legal, non problematic, upgradeable (sony wont let its flagship br player to die or be not up to date) solution to play my hddvd and br collection. its a shame that there is no easy, not so expensive, plug and play solution for bitstream sound from hidef media from htpc.

Wow, what a great article! Not only is it the most detailed technical article of this sound card ever written, but Devon Cooke even manages to put the card in perspective with the insanity of an entertainment industry that would spur a market for such a card. The many hyperlink references are greatly appreciated.

Does the Asus version of TMT work on 64-bit Vista versions? The last time I checked, Arcsoft still treated 64-bit Vista owners like lepers and their TMT software is 32-bit Vista and XP only.

+1

In addition, DVD supports high-bit-rate formats, such as 24-bit at 96KHz. A quick example from Chesky's website:

Even if I know the answer, why just why didn't you test bit-perfect S/PDIF playback? I didn't see any testing of Dolby Digital or Dolby ProLogic either! For HTPC users it is important to know this stuff. I know of some sound cards which have problems passing through Dolby Digital audio or can not handle ProLogic encoded tracks well (for example, high pitched noise on front channels).

At any case this sound card is all but crap. For the money though one could get these: http://www.logitech.com/index.cfm/speak ... 4&cl=us,en

...and those Logitech speakers can handle Dolby Digital and DTS decoding in hardware so all you need is hookup that integrated audio controller through S/PDIF. That Asus is overpriced. It's a bit schocking though that SPCR made an article of a sound card... I mean, there isn't much in a sound card that could cause noise. Also in case you need to know which sound cards have excellent audio output then look around and make sure you get to know every chipset on the market, the VIA Envy24, the C-Media CMI8788 Oxygen HD, etc...

Apparently bit-perfect works with ASIO4ALL. Not sure about DD or ProLogic pass-through, but the cheap VIA Envy24 cards support it and I'd be surprised if the Xonar didn't.

To be honest though anyone using bit-perfect output won't be interested in this card. There are much cheaper cards that do bit-perfect via digital out, and even the legendary Chaintech AV-710 has a pretty good DAC for analogue.

My current HTPC system is an Athlon X2 4200 running on a 780g mobo with built in Radeon 3200 graphics. Full hardware video decoding for effortless playback of HD video, and for less than £120 including the case. I could easily add a Radeon 4850 for full TrueHD sound pass-through and it would still cost less than the Xonar.

PS. Nice review, as always, plenty of detail.

I think the extra power connector is for a +5VDC supply, which PCI-E is missing over PCI (other PCI-E Xonar cards also have them, however the PCI cards do not).

Thanks for pointing out my mistake. I was aware of the 18 / 20 dB standards for headroom, but I hadn't realized that this is designed into equipment; I use them as a means of setting reference *input* levels into digital recording equipment (I'm in North America, so I use 20 dB). My confusion comes because I was not aware the same standard is used for going the other way (i.e. going digital->analogue instead of analogue->digital). Put in other words, I had assumed that 0dBFS was the reference level that should correspond to the analogue reference level of -10 dBV.

As a side note, I don't think we should consider the Xonar "pro" audio equipment; it seems pretty consumer oriented to me, and I would expect it to interface with equipment that is not up to pro standards.

In light of what I now know, I still think the audio levels are high, but perhaps not disasterously high. My reasoning is this:

- Most digital equipment is designed so that 0dBFS = reference level +20dB, allowing for 20dB of headroom
- Our 1 kHz test tone had peaks at -3.2dBFS, and yielded an output voltage of 2.26VRMS, or +7dBV.
- Normalizing the test tone to 0dBFS would bring the output to ~+10dBV.
- This means that the maximum possible *peak* voltage should be +13dBV, based on the known 3 dB crest factor for sine waves.
- +13dBV is 23dB above the consumer line level of -10dBV, yielding a "headroom" of 23 dB, or 3 dB higher than the standard 20 dB.

I must admit that I would expect a *lower* amount of headroom to be advantageous for a digital output device, since having a high headroom in the first link of the signal chain effectively requires that every other device in the signal chain have a headroom that exceeds the first.

I'm pretty sure electronics aren't designed this way, but I would consider an appropriate output level for DACs to be 0dBFS = +12 dB above reference. Why? Because nearly all digital sources are normalized to 0 dBFS, and 12 dB is a fairly commonly used rule of thumb for average crest factor in music and speech (I dispute your 16 dB number). This makes more sense to me than duplicating the 20 dB headroom used when going analogue->digital, since it brings the reference levels back to where they should be, with the average RMS levels at 0VU (assuming no dastardly loudness war compression).

Anyway, I'll be correcting the article now that you've pointed out my mistake.

As far as I know the 48x0 series is capable of outputting these formats as downsampled PCM after they have been decoded, but not bitstreaming. I cite the many posts on AVS forum in my support, as they seemed pretty sure it could not do it (this is why there is a 150 page thread in support of the HDAV).

I second your vote for the AV-710 and an external DAC though. I've been using the AV-710 in my own HTPC for years, though I'm still saving for that DAC.

Because I'm not interesting in doing a review that does nothing but verify that features are working correctly. I'm all for verifying specifications, since these are often fudged and it can be helpful to have them tested in standardized ways, but I don't see the point in verifying features. It's boring to test and boring to read about.

I did wade through all 153 pages the HDAV1.3 thread on AVS forums ... they did a much more thorough job of feature verification than I could hope to do, and I cited all of the anomalies that they found (with a few minor exceptions that have already been fixed ... I believe decoding one of the Dolby formats may have been one of them).

In addition, decoding any of these formats is a software task that doesn't actually involve the hardware itself ... and if you get different software, you can overcome any bugs in the included TMT software. DD Live and DTS interactive are exceptions, since these are hardware accelerated *encoders*, but these are simply not in the scope of the review. Sorry, but we can't examine everything.

Then you are reviewing wrong. Please concentrate in other PC peripherals and leave sound cards alone. You guys just don't have enough expertise in the audio field. **

** I know you have great instruments in your lab, but what sound card did you review before the Xonar? Nice review, but any good review would have verified that all features work as expected. Any good review would focus on audio fidelity, not on verifying specifications.

Software task, bulls**t. If this was intended to be a review that should entice HTPC users then why didn't you test out a *real* A/V receiver with Dolby Digital / DTS decoding? True hardware, no matter what brand, is always better than crappy software. Who in the world would use software based Dolby Digital Decoding anyway, if they are serious about audio?

You should have tested Dolby Digital Live as well and test the audio output in addition with a professional quality headphone amplifier and possibly Grado headphones. Or connect the sound card directly to studio monitors and compare it to a reference sound card, preferably a Layla3G or other high end professional sound card.

Respecting all points, the review is incomplete. It was good though but if you want to live up with the SPCR quality of reviews then test more than just the specifications. As an example when you guys review HDDs then you also measure airborne acoustics and vibrations from which NONE are mentioned in ANY documents of the manufacturer(s). Still in the frame of "verifying specifications" ???

Leave the audio field unless you are serious about it.

What is it about audio that attracts foul-mouthed snarky bozos? LodeHacker you are way out of line. This is not some scummy dive -- You don't have a clue about fair discussion in this forum.

incorrect. many (all?) HDD manufacturers include decibel measurements, e.g.:

http://www.westerndigital.com/en/produc ... anguage=en

Agree.



Not quite correct. dBV always refers to rms voltage, so the maximum output would still be 10dBV=3.2Vrms while the peak voltage of the sinewave would be 4.4V (3.2*sqrt(2)).

The headroom is measured as the difference between the nominal and maximum level in dB so it becomes 20dB.



I agree that it requires that the rest of the chain has the same headroom as the first part, but I see this as an good thing. If the soundcard as the source is the weakest link in the chain, then you wouldn't be able to take advantage of possibly well designed electronics further down the chain.


This crest factor varies a lot between different types of music. Classical and metal being on opposite sides of the spectrum.



Thank you, I'm glad you're not too proud to admit a honest mistake.

Best regards
OJG

They did devote a rather lengthy passage to audio fidelity.



Because that's what this soundcard is supposed to do. That's why it has a daughterboard and costs 250 Bucks. It's meant to replace an external A/V receiver. Using one would defeat the purpose of this card (unless you're into the DTS-MA and Dolby TrueHD shenanigans).



Why? You have just admitted that "audiophiles" such as yourself, who spent lots of money on "professional" equipment would never buy the Asus card in first place. SPCR reviews are not intended to reassure you that your investments in your audio equipment were justified, they are meant to help people, who might really be considering to buy product make up their minds.

I looked at the full RMAA results and discovered an anomaly: the frequency-response curves extend past Nyquist! Any ideas about what's really happening here?

On further investigation, that appears to be correct, sort of. The 4800s can output 8 channel LPCM, so can output the decoded DTS-HD. However, PowerDVD current down-samples as there is no API in Windows for Protected Audio Path (PAP). The Xonar uses the proprietary Cyberlink software to implement PAP.

So, if you want DTS-HD bit-perfect on a 4800 you have a few options. You can use eac3to to decode it without any down-sampling, or rip it with any other software for similar results. Alternatively, you can wait for Microsoft to come up with an API.

You only get DTS-HD or TrueHD with the Total Media Theatre software, it does not work with Media Centre or MPC-HC etc even with the Xonar, unless you rip

This is completely faulty reasoning, given that almost all hardware produced these days has some firmware component, and obviously just about anything is better than "crappy software" (duh), and it is trivial to make a cheap, crappy hardware-based codec implementation (plenty exist). It is difficult to purchase a piece of consumer electronics these days that doesn't contain software, and anything that involves audio decoding is almost certain to have it implemented at least partially in software. I say this as someone who's day job involves AV codecs in an embedded environment.

"True hardware" (what does this even mean?) is not always "better" (what does this even mean?) than software, nor does this statement make any sense whatsoever.




Personally, I'd like it if SPCR left the audio field if for no other reason than the hostile, illogical and snide people who tend to reside there.

Funny how we can discuss a video card on FPS in this game or that but sound causes such a commotion because it’s not so easily quantifiable for most people. Audio measurements are not like FPS and everything sounds different in your house than it did in the store. We have a hard time mixing computer/tv/audio. They are incompatible formats being forced together and it’s about time.

I don’t expect the Xonar to deliver magic for 250. I do, however, expect it to work with Vista 64 and all the options to function correctly. It is meant to be fiddled with (replaceable op amps), a work in progress, just like the HTPC market. It must fill a broad market segment with screwy Hollywood requirements from lawyers who have no clue in what it takes to make it work. It is a jack of all trades master of none.

The HTPC is not quite ready for primetime when compared to quality off the shelf single purpose consumer electronics. HTPCs have compatibility bugs (software and hardware) that most consumer electronics don’t. First /early adopters have always been guinea pigs.

Thanks for the article I hope you will do more.

PS Go to a high end A/V store and get a benchmark for your eyes and ears.

No, sorry.

I would speculate that it's possible to make Nyquist calculations outside of the domain that Nyquist is valid (i.e. 1/2 sample rate), but I really have no idea. Or perhaps the graphing library is extrapolating the curve beyond the test data in order to keep test data comparable across multiple sample rates.

Given that this card is the price of a standalone Blu-Ray player, I can't see much of a market. Is having everything in one case really that important to people? By leaving a optical drive out of your HTPC, you can go with a much smaller case. I'd rather have the super small HTPC and standalone Blu-Ray player stacked on top of each other in the same footprint as a fat HTPC case and without all the headaches of PAP and other DRM nonsense. Meanwhile, to really enjoy HTPC goodness, shouldn't you be ripping your disks, anyway? Isn't that why people are slavering over the 2TB GP drives? I'm sure there are a few hundred people really into this Xonar solution (at least 1 per page of the AVSForum thread), but for the rest of us, meh! I don't think this one was really worth a review. A blog post noting the ridiculousness of PAP and pointing people to the AVSF thread would have been good enough. But then again, I read the whole review, so who am I to complain . . ?

At risk of feeding the troll, I will respond to this.

Sorry, there is no way you can defend this statement. I am the reviewer, ergo, I get to decide what goes in the review. You are welcome to tell me whether or not you find it useful, but I suggest you do so in less inflammatory language. You have a very twisted idea of what we do at SPCR if you think the review was intended "to entice HTPC users". My review gives my opinion of the product, no more, no less. If you want a review that gives you reasons to buy a particular product, go find a review site that rewrites PR shill and considers "feature verification" more important than an analysis of whether the product might actually be useful or well designed.

I don't know where you got the idea that I think *only* specifications matter ... verifying specs was a very small part of my review. In fact, the only attention I paid to them was in the context of evaluating fidelity.

I will admit quite openly that neither I nor anyone else at SPCR has ever reviewed a sound card, but if you think that means we lack knowledge of audio you are sorely mistaken. I make my living as a sound recordist in the film industry, and Mike built and tested speakers long before SPCR ever started.

On the subject of decoding Dolby Digital / DTS, you are simply dead wrong. Both of these formats are codecs, and there is only one correct way of decoding them. This is true whether the underlying logic is implemented in software or hardware. With respect to audio fidelity all DD / DTS decoders are 100% equal no matter how they are implemented.

To the best of my knowledge *all* PC-based decoding of these formats is in software, since a hardware approach would require a standardized API that, as far as I know, does not exist (not to mention the added cost of adding such hardware). I suppose there could be a few specific hardware / software combos that use a proprietary API, but I see no reason for such a combo to exist.

Your suggestion that we test the card with headphones is somewhere between laughable and confused, as is your preference for Grado cans without specifying any particular model. Headphones are not an accurate way of evaluating audio quality, especially when the card isn't even designed to support them. No audio engineer would ever mix audio on headphones because they don't give an accurate idea of how the audio sounds *in a room* (not to mention the complete lack of stereo imaging). A good engineer might listen to the audio on headphones after mixing if the target system is expected to involve headphones, but he would never mix on them. The same goes for testing.

Your suggestion of using studio monitors does have merit because they tend to have well known performance characteristics, and if we had access to a studio, we probably would have gone that route. And, if we had experience with any other high end cards, we would have used them as a reference. However, I can assure you that Mike's custom-built speakers are of good enough quality to distinguish fine differences in the signal chain. They have the added advantage of being part of a system that I am intimately familiar with. Our A/B test comparing the card's digital output to the analogue output did a good job of comparing the Xonar with a sound system that is of very good quality. This is true regardless of the fact that you've never heard it and can't compare it to products you are familiar with.



I don't think you have to worry about any more sound card reviews from me. I'm too busy with my career as a location recordist to contribute regularly to SPCR.

What do you suggest?

I must admit I am hesitant to get involved on an audiophile level because I truly believe what I said when I suggested skipping the test results. Even if it is possible to qualify or quantify differences between various high end gear, past a certain point I don't think the differences matter. For the most part, that differences are so small that it's impossible to tell which is "better" even when you can verify that the difference exists. I don't see the point of blind ABX testing because if you have to blindfold yourself to verify that you can hear a difference, the difference isn't big enough to worry about. It would not surprise me to learn that differences in the mood of the listener, variation from mastering studio to mastering studio, the preferences of the engineer, and differences in room acoustics have a greater impact on the sound than the playback electronics.

Speakers may be an exception to this rule, but for the most part, consumer gear of a decent quality level is more than good enough to reproduce audio cleanly without major distortion. Perhaps this is audiophile heresy, but what matters is whether or not the emotional content gets through, not whether the signal is so detailed you can hear the woman at the back of the theatre cough.

In fact, I would argue that one of the reasons vinyl remains so popular is because it blurs the audio in a way that hides flaws in the mix and mastering process. Real music is not perfectly distinct ... multiple instruments should (usually) gel together into a single song in such a way that you hear the song, not the instruments, and the relentless pursuit of clarity and detail can destroy this illusion, especially on pop recordings where all the instruments are close-miked. Live music inherently lacks the ultra-clear precision of studio recordings, and I think a little blur helps bring studio recordings closer to the experience of live audio.

The Pink Floyd recordings I mentioned are a perfect example of this; the greater detail afforded by Xonar made the tracks seem less musical. I spent my time picking the mix into its individual components rather than enjoying the music. I should add that I prefer listening to this album on vinyl precisely because I can feel the "groove" better than the clearer CD masters.

Sorry for the rant ... I really would like to know what's out there in the way of high end benchmarks.

Agreed. I didn't mean to suggest otherwise, though looking back at what I wrote I can see that I did imply it. I mention 12 dB because it is often used as a rule of thumb for converting VU readings into p-p readings.

Based on what I have read elsewhere and on conversations with experienced people I trust, I have drawn the following conclusions. Tell me if you agree:

- There is no universally agreed on standard for what 0dBFS means in terms of voltage.
- The 0dBFS = +6dBV (+2Vrms) "CD" standard that you mention has been informally adopted by most consumer level devices that output via RCA jacks.
- The "reference" line level of -10 dBV is essentially meaningless for consumer-level digital equipment because none of these devices contain VU meters, and what matters is peak voltage, not average audio levels.

I think I will use +2Vrms as the reference (maximum) level that I expect the Xonar to comply to. I am aware that having extra headroom is not entirely a bad thing, but I don't feel it's uncontroversially a good thing either. There's no question that the card clipped the inputs on my (not low end) Yamaha receiver. The speaker test audio (and several "Windows" sounds) were heavily distorted during playback.