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Print 39 comment(s) - last by shortylickens.. on Apr 3 at 8:46 PM


Xonar EMI shield concept

Xonar D2K at CeBIT, image courtesy of VR-Zone
ASUS readies its upcoming Xonar D2 and Xonar D2K PCI and PCIe x1 sound cards

ASUS last week at CeBIT demonstrated its upcoming Xonar-series sound cards. The upcoming Xonar-series spawns two variants, the D2 and D2K in PCI and PCIe x1 interfaces. Dolby Digital Live and DTS Connect multi-channel audio encoding technologies are available for digital multi-channel audio. The Xonar-series also features 7.1-channel analog outputs for those that prefer analog to digital.

Early reports claim the ASUS Xonar-series feature an Analog Devices audio DSP, however, ADI denies any involvement in the sound card.

“I checked with our sales team and there is not an ADI part in this unit,” said Sandra Perry, product line manager, SoundMAX, DSP Division.

ASUS also touts Dolby Pro Logic IIx, Dolby Virtual Speaker and Dolby Virtual Headphone technologies for multi-channel upconverting and surround sound with stereo speakers and headphones. ASUS rates the Xonar-series with an 118dB playback and 115dB recording signal-to-noise ratios. The upcoming Xonar-series sound cards support 24-bit/192 KHz playback and recording resolutions and ASIO 2.0 as well.

ASUS internal testing reveals the Xonar-series is capable of low total harmonic distortion rates. The Xonar-series has 0.000006% THD on all eight analog outputs and the single line input, between the frequencies of 20Hz to 20 kHz. ASUS also equips the Xonar-series with an EMI shield and touts it provides “stable audio quality.”



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RE: Wow
By exdeath on 3/23/2007 3:37:43 PM , Rating: 6
Someone tried to convince me that a dedicated high end DVD player is far better than the DVD drive I use in my HTPC, because of the cheap PC ribbon cables, noisy power supply, interference, software decoding, etc.

How do you explain to someone like that the concept of DIGITAL...

A stream of bits decoded off a disc over a 50 cent SATA cable translates to 128 0 0 and send over a $5 HDMI cable translates to 128 0 0 on the display device at that exact pixel, the same exact way a $2000 DVD player.

What do those people think is inside their $2000 DVD players? With a HTPC I have the advantage of altering the codecs, etc., I'm not locked into a black box with pre-configured hardwired firmware. HD upscaling? Cleaner decoding? Buffering layer changes? Region compatibility? All things that can be done in software 100 times better than a dedicated box.

People that like to by expensive electronics are having a hard time justifying the cost difference in the digital domain. With analog signals, cables and things like that can make or break a good AV system. With digital you can use a $5 HDMI cable that is 50 feet long as long as it works. About the only thing to gain by paying for expensive digital cables is longer runs.

The signal can be distorted to hell and back on the shittiest cable possible, and as long as the threshold between a '1' and a '0' is preserved, it will look just as good as a $1000 cable on the same screen.


RE: Wow
By mendocinosummit on 3/23/2007 4:08:21 PM , Rating: 2
$5 HDMI cable, wow, I would like to know were your buying yours at. I do agree with you though.


RE: Wow
By paesan on 3/24/2007 8:05:27 AM , Rating: 2
Try monoprice.com and you will find hdmi cables that cheap. I have many including a 25' running from my pc to the tv.


RE: Wow
By digitaldreamer on 3/23/2007 4:26:55 PM , Rating: 3
I agree with most of your points regarding digital signal transfer. However, there are differences in the way video upscaling and deinterlacing is done on HTPC and dedicated players.
Most run-of-the-mill PCs don't really offer the quality per-pixel motion-adaptive deinterlacing found in players with Faroudja or Silicon Optic Realta chips, although a lot of that is changing with ATI's and NVIDIA's new GPUs.

regards,
MAJ


RE: Wow
By exdeath on 3/23/2007 4:42:21 PM , Rating: 3
Yeah, but in software, things can be changed and upgraded. I was thinking more a pure software decoder engines more than incomplete hardware offloading in graphics chips. That is all configurable. Personally I have no interest in upscaling DVDs after seeing 1080p with 1:1 mapping so I don't really pay attention to that realm.

But to say a PC DVD drive isn't as accurate in video rendering as the drive in a dedicated videophile player because of a cheap low quality ribbon cable? Come on... 12345 is going to be sitting in a DRAM chip as 12345 somewhere and fed to a TMDS transmitter all the same.

That is the whole point of digital after all =D


RE: Wow
By Comdrpopnfresh on 3/23/2007 4:29:19 PM , Rating: 1
There is really no such thing as a digital circuit. Digital circuitry is just analog- with brackets of voltages cordoned off as 0's and 1's. If the air has static, or the cable runs too long and experiences voltage drop, or the internal wires are not balance and properly shielded from one another- there can be inductance which changes the voltage values above of below their norm and changes your 0 and 1.


RE: Wow
By exdeath on 3/23/2007 4:58:55 PM , Rating: 4
Yes, the signal can be garbled off the board, but as long as those 'brackets' are maintained the signal goes through 100% accurate. It's all or nothing, the only requirement is that the cable be at least good enough quality and low resistance enough that the weak low voltage signal can be picked up on the other end.

If 5 volts is the minimum threshold to be a '1' and you send 0010 in pulses of 0.5 0.5 5.5 0.5 and you get a noise on the line and end up with 0.6 0.7 6.9 0.3 , in digital its still 0010 despite the noise. This is why digital systems have been used in computers from day one.

Thats not exactly how the signal is encoded in digital but it gets the point across. Any signal is analog by definition of the word 'signal' but the encoding method is digital and there is a threshold between a '1' and a '0' along with things like error correction, checksums, differential transmission to cancel mutual noise, etc. Things you don't have with raw analog.

On a analog transmission if you get noise like that, you just shifted all your hues, saturation, etc. and you can't get consistent result, esp. with the way color is encoded as phase and frequency. With digital everything is just evenly spaced strobes at a fixed frequency with a fixed amplitude.

With digital, the color grey is still 128 128 128 even with moderate signal noise as the digital encoding scheme can still pick up the swings even with significant noise. With analog you dont even know there is noise to begin with, you just end up with 135 123 140 on the other end instead of 128 128 128.

I'm simplifying it alot, but thats the basic idea.

The biggest problem with digital HDMI cables is impedance mismatching where you have connectors, couplers, etc.


RE: Wow
By DragonMaster0 on 3/23/2007 10:50:53 PM , Rating: 2
Actually, with HDMI/DVI you're right, there's no difference.

The only difference with the cables might be that a $5 one will not last long, and a $25 one with minimal gold plating will. The other thing is that jitter might be present, but every TVs pass the data input through a signal processor, which corrects the signal.

With analog signals, power supply noise, DAC quality, etc. matters a lot more(Not to the point of buying a $2000 player tho. Get a $150 player, get $40 worth of better quality components, replace the ones in the player with those, and you have what a hundreds worth more player is).

SPDIF is a digital signal, but might not always give the greatest quality, but that depends of the source and receiver. Jitter might affect the SPDIF decoder and audio DACs, as they're hardware(and synchronous, data comes in and out) and do not necessarily understand clearly an unclear signal. A software DSP would correct it(It has time to work on the signal), but not every receivers work with one.

Here, the computer has an advantage. For example, the computer doesn't read the DVD in real-time, so it has time to re-read the data if it's been misread. To the opposite, a standalone DVD player running at 1x has to do everything in real time, and will use hardware-dependant error correction, and the data on the disc isn't re-read a second time.

It's the same thing through all the computer : The data is asynchronous, it's sent in packets, and re-sent and corrected if it's not valid, so, with a computer, you're sure that the data read by the laser is the same going to the PCI and PCI-Ex buses to your sound card and video card(Unless there's processing somewhere between). An overly scratched disc is the only thing that could get the data wrong.

Then, it's up to the sound and video card to do the async to sync digital job(They're the only things that can get the sound worse). For DVI/HDMI, it's up to the TV to be good. For the sound, the sound card might play with the sound quality, and a good external sound card is preferred to a not-high-end receiver(Simply for the way the stream is handled between the SPDIF or I2S stream transmitter and receiver).

OK, compared to the computer, a $2000 player does every thing in sync and in real-time and doesn't take the time to correct everything. It's DVD drive is running at 1x, forget error correction, and the signal that comes in is coming out instantly. Every of the ICs in the player could be affected by jitter, as well as the signals between components as they are not asynchronous packets.

BTW, I've been talking about jitter for a while, it's important because if the signal shape is not as square and synchronized as possible, the reciever might not know immediatly if the bit received is switched or kept to 1 or 0, it might hesitate and cause errors in the output it will give. A system working in real-time is going to be affected by this as it's directly affected by the input signal. DSPs and computers process data in software and not in sync, so they have the time to receive the data correctly and handle it the same way.


RE: Wow
By shortylickens on 4/3/2007 8:46:47 PM , Rating: 2
Thats what I try to tell people all the time and they never listen.
It only needs to be able to distinguish between a 1 and a 0.
Maybe I should print out your speech and hand it the next person I see trying to act smarter than they are.


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