[JohnnyGoTime]

Hi everyone, total noob here but I've been reading audio threads on this site & others for a few days so I can try to ask an intelligent question...I will give you my scenario and am hoping somebody can give an answer which helps me understand a bit deeper than "sound card beats onboard audio every time".
 
I just built a Win8 cpu and will use it for 50% games, 50% music.
I will be alternating between 5.1 surround & Samson SR850 headphones (using the headphones slightly more often.)
I don't have the surround speakers yet, but when I get them they will be sub $200.
My onboard audio is Realtek ALC1150 (Sabertooth Z87 mobo).
 
After a bunch of reading, I'm happy to buy the Xonar DXG (because it's cheap and PCI-E with generally glowing reviews.)
 
But the question gnawing at me is: *why* will this Xonar be a step-up from the onboard audio? I think the following factors are the big ones, please let me know what categories I've missed.
 
** SNR **
Realtek 1150: 115dB 
Xonar DGX: 100db (headphones) or 105db (speakers)
--> Realtek is better?
 
** Impedance **
Headphones impedance: 32ohms (Samson SR850)
Realtek 1150: All I've found is a forum comment which said the Realtek has 2 Ohm output impedance, which is 1/16th that of the headphones.
Xonar DGX: "optimized for 32ohms"
--> Realtek is more than good enough for my headphones?
 
** Freq. Response **
Headphones: 10Hz-30kHz 
Realtek 1150: 40 Hz – 15 kHz,dB +0.02, -0.07 (not sure how to interpret this)  
Xonar DGX: <10Hz to 48kHz (better than human hearing can even detect..?)
-> These Realtek numbers don't seem correct, but I couldn't find otherwise. But if they are, then this is an area where the 1150 isn't able to use the full range available to the headphones.
 
** THD **
Realtek 1150: 0.0043 
Xonar DGX: 0.0025
--> From what I've read, the Realtek number here is low enough that I won't ever be able to tell the difference..?
 
In sum, what are some good reasons to go with a sound card such as Xonar DGX when I have a Realtek 1150?
Thanks for reading this long post!

 

[MajorError]

I'll say this right up front:  I don't even use a sound card...
 
Probably the biggest reason to move to a dedicated sound card is interference.  The on-board audio circuitry is packed into the system's southbridge, along with a host of other functions.  http://en.wikipedia.org/wiki/Southbridge_(computing)
There's only so much that can be done to shield those circuits from the others on the chip, so there's a very good possibility that you'll be able to, quite literally, hear the bits flowing (if you turn the volume up.)  Even with an internal card, it's still possible to pick up this interference.  If I had to guess, in this case I'd place the blame on the general nature of the PC power supply.
 
Before I went to external DACs & amps, I had my AKG K701s connected through my old (underpowered) Creative X-Fi (fatality something-or-other with the front panel kit,) and was still able to hear the interference, just not as badly as on-board sound.

 

[PurpleAngel]

   "sound card beats on-board audio every time".
I just built a Win8 cpu and will use it for 50% games, 50% music.
I will be alternating between 5.1 surround & Samson SR850 headphones 
My on-board audio is Realtek ALC1150 (Sabertooth Z87 mobo).
After a bunch of reading, I'm happy to buy the Xonar DXG (because it's cheap and PCI-E with generally glowing reviews.)
But the question gnawing at me is: *why* will this Xonar be a step-up from the on-board audio? I think the following factors are the big ones, please let me know what categories I've missed.
** Impedance **
Headphones impedance: 32ohms (Samson SR850)
Realtek 1150: All I've found is a forum comment which said the Realtek has 2 Ohm output impedance, which is 1/16th that of the headphones.
Xonar DGX: "optimized for 32ohms"
--> Realtek is more than good enough for my headphones?
In sum, what are some good reasons to go with a sound card such as Xonar DGX when I have a Realtek 1150?
Thanks for reading this long post!

Motherboard on-board audio gets better every year
Your comparing a really low costing sound card to the latest motherboard on-board audio chip-set.
Your also using a low cost ($50) headphone (SR850), so it's not really worth it to spend more then the $35 you might spend for the DGX, for trying to improve audio quality.
 
Where did you see that the Realtek 1150 has only a 2-Ohm output impedance, does not sound right, but I will investigate.
 
You can always hold off buying an add-on internal sound card, maybe save up for the Sound Blaster Z (SB1500), $100, sound card.

 

[stv014]

Originally Posted by JohnnyGoTime /img/forum/go_quote.gif
 
** SNR **
Realtek 1150: 115dB 
Xonar DGX: 100db (headphones) or 105db (speakers)
--> Realtek is better?

 
115 dB is what the Realtek chip itself is capable of in a "perfect" implementation, but in reality on most motherboards it will be worse because of the already mentioned interference issues. With an internal card, at least you have a reasonable chance of not getting any audible interference (it depends on the PC and how well the card is designed, for example I do not get interference in my machine with any of the cards I have, which is unfortunately not the case for the onboard audio).
 
So, you need to try and find it out yourself: if you do not hear any noise while playing a silent WAV file, even under system activity, then you are lucky and your onboard audio is fine as far as noise is concerned.
 

Originally Posted by JohnnyGoTime /img/forum/go_quote.gif
 
** Impedance **
Headphones impedance: 32ohms (Samson SR850)
Realtek 1150: All I've found is a forum comment which said the Realtek has 2 Ohm output impedance, which is 1/16th that of the headphones.
Xonar DGX: "optimized for 32ohms"
--> Realtek is more than good enough for my headphones?

 
The Xonar can probably output a few dB higher voltage into high impedance headphones, but its headphone output otherwise might not be that great. It probably has at least 10 Ω output impedance, and the DRV601 chip used on it (originally designed for line out applications) has relatively high distortion driving low impedance loads.
 
With the Realtek, it again depends on the implementation, which is often not good. While the ALC1150 alone does in fact have an output impedance of only 2 Ω, and can drive low impedance loads with lower distortion than the DRV601, motherboard manufacturers tend to add serial resistors up to 75 Ω. Another frequent problem with onboard headphone outputs is that they are often AC coupled with small (for example, 100 uF) capacitors that degrade the bass response.
 

Originally Posted by JohnnyGoTime /img/forum/go_quote.gif
 
** Freq. Response **
Headphones: 10Hz-30kHz 
Realtek 1150: 40 Hz – 15 kHz,dB +0.02, -0.07 (not sure how to interpret this)  
Xonar DGX: <10Hz to 48kHz (better than human hearing can even detect..?)
-> These Realtek numbers don't seem correct, but I couldn't find otherwise. But if they are, then this is an area where the 1150 isn't able to use the full range available to the headphones.

 
The frequency response specs can only be correctly interpreted if dB tolerances are also specified (as they are for the Realtek). For the Xonar DGX, it is probably -3 dB. In the case of headphones, you can usually ignore the manufacturer's specified frequency response, and check some independent measurements instead (InnerFidelity etc.).
 
In any case, the ALC1150 by itself is unlikely to have any significant frequency response problems, and the limiting factor is again the implementation. Low frequency roll-off is caused by undersized output capacitors on the motherboard, and with a headphone load, high output impedance (up to 75 + 2 = 77 Ω if you are unlucky) causes further frequency response and even distortion issues.
 

Originally Posted by JohnnyGoTime /img/forum/go_quote.gif
 
** THD **
Realtek 1150: 0.0043 
Xonar DGX: 0.0025

 
Note that these are for the line output. With a headphone load, it will be much higher, but probably still lower than that of the headphone itself, except maybe in the case of the Xonar DGX in the high frequency range with high quality headphones that need a relatively high amount of current. On a blog where various devices have been measured with high end gear, the Xonar U3 (similar output stage to the DGX) had about 0.1% distortion at 3 kHz when driving a 33 Ω load at 0 dBu level. In the case of the Realtek chip, much of the distortion will come from the interaction with the output impedance (if it is high), and possibly also from the output capacitors (if they are too small) in the bass range.
 

Originally Posted by JohnnyGoTime /img/forum/go_quote.gif
 
In sum, what are some good reasons to go with a sound card such as Xonar DGX when I have a Realtek 1150?

 
To summarize the above, the sound card can be better or worse depending on how well the Realtek ALC1150 is implemented on your particular motherboard, so it is not possible to give a definite answer without actually measuring it (and even then it can depend on the rest of the PC, the power supply, GPU, etc.). The Xonar is a relatively safe bet in the sense that it is better than the (unfortunately common) bad onboard audio implementations.

 

[JohnnyGoTime]

  Motherboard on-board audio gets better every year
Your comparing a really low costing sound card to the latest motherboard on-board audio chip-set.

 
That really hits the nail on the head, I think.

As far as onboard audio goes, I've got a good one so I probably won't see much benefit from a cheap card, and I'm not ready ready to take the plunge for a more expensive sound card yet.
So I will just try the headphones for now and go from there. Thanks!

 

[JohnnyGoTime]

[deleted]

 

[JohnnyGoTime]

  To summarize the above, the sound card can be better or worse depending on how well the Realtek ALC1150 is implemented on your particular motherboard, so it is not possible to give a definite answer without actually measuring it (and even then it can depend on the rest of the PC, the power supply, GPU, etc.). The Xonar is a relatively safe bet in the sense that it is better than the (unfortunately common) bad onboard audio implementations.

 
Argh, reply-fail...was trying to say this to stv014:
 
Wow, that's exactly the kind of explanation I was hoping for!
 
This will take me awhile to digest, so I wanted to say thanks right away for all of this effort, and I'll come back with followup questions if I have them.
 
Great job stv014!!

 

[happycamperjack]

You guys should check out the new motherboards from Asrock such as Asrock Z87 Killer. It has EMI shielding for the Realtek 1150, and a amp to drive 600ohm headphone!! What's crazy is that the board only cost around $130 right now. So there you have it! 7.1 for the gamers, and 600ohm stereo for the audiophiles. 

 

[NamelessPFG]

You completely overlooked the fact that the Xonar DGX would give you Dolby Headphone and DS3DGX, the latter of which I would expect to work much better than Realtek's 3DSoundBack.
 
Considering that most Realtek drivers bundled with motherboards are rather basic in their functionality and haven't licensed any virtual surround tech, it's a very important distinction if you don't want to mess around with installing modified Realtek drivers bundled with X-Fi MB/MB2/MB3 software packages.
 
Also, as everyone has stated, Realtek's quoting best-case-scenario figures, and most motherboard manufacturers will wind up botching something in their implementations to the point of making it sound awful. *glances at a Gigabyte GA-P35-DS3P which has very audible noise if set to headphone mode in the drivers, even from the rear output*

 

[happycamperjack]

I'm listening to it right now, I don't hear any noise at all! 7.1 or front stereo(drive up to 600ohm headphones). I'm completely blown away! I'm an absolute realtek hater before this. Their minuscule noise drove me nuts! But I'm telling you man, you gotta try this. Asrock's EMI shielding and PCB shielding are amazing. 
 
As for upmixing, it supports DTS NeoC. Not too shabby.
 
I think this is the first series of motherboard ever made that has amazing sound for both 7.1 (gaming) AND stereo (music). And it's cheaper than a DAC! You gotta give it a try man.

 

[sammi84]

Yeah I have a MSI Z87-G45 motherboard with the Realtek alc1150, and my Schiit Modi DAC just crapped out, so I switched back to the onboard sound, and I can't hear a significant difference. Not an objective measure, but this is my subjective experience. Take it as you will

 

[Darkened]

  Yeah I have a MSI Z87-G45 motherboard with the Realtek alc1150, and my Schiit Modi DAC just crapped out, so I switched back to the onboard sound, and I can't hear a significant difference. Not an objective measure, but this is my subjective experience. Take it as you will

I have the exact same motherboard and I get absolutely zero audible noise. I've been making a fuss about figuring out which amp or dac or amp/dac combo I want to get started off with but if I don't need an amp to power my headphones and I have a pretty good source, do I actually need to get anything?
 
I need to find a place with amps/dacs on display so I can test them out

 

[obsidyen]

Modern computer sound cards, either onboard or separate, have no audible noise. I think, for low impedance headphones such as my Fidelio L2, an external dac/amp is absolutely useless and a waste of money. Realtek 1150 sounds absolutely great with good headphones.

 

[cel4145]

Modern computer sound cards, either onboard or separate, have no audible noise. I think, for low impedance headphones such as my Fidelio L2, an external dac/amp is absolutely useless and a waste of money. Realtek 1150 sounds absolutely great with good headphones.

While it is certainly true that computers have improved significantly over the years in this regard, it's quite impossible to make this claim for all computers. Noise can be a result not just of the sound card or motherboard, but other parts of the hardware configuration as well. And of course, not all sound cards or motherboards are created equal.

And then how much difference an external dac/amp makes is also partially a personal value judgement.

 

[RonaldDumsfeld]

Here is a link to the Realtek product description page for ALC 1150 http://www.realtek.com.tw/products/productsView.aspx?Langid=1&PFid=28&Level=5&Conn=4&ProdID=328
 
You can also download the detailed product datasheet from the same page. Section 9 (~page 72-74) lists the analogue performance in splendid detail.
 
It's pretty damn good. Up to 115 dB SNR on the main DAC  What you would have expected in a high end/professional unit costing $2000+  15 years ago. 10 years ago it would have been project studio quality and cost $500+. Even 5 years ago or less it compares well with boxes costing $150+. Now it comes as a $10 part on expensive motherboards. What's not too like? It even has a 2 Ohm headphone socket output impedance!! Out your heart out Pono!
 
It must be able to meet those specs too. At least using the supplied reference circuit. If it didn't it would get returned. Of course some assemblers will try and skimp on the reference support circuit or make other mistakes but you'd have thought some of them must have got it right? I mean why not? Motherboard sales are falling as people move to smaller devices. Why not include great audio on the board for a few dollars extra and save your customers getting nickel and dimed for after market DAC and head-amps?
 
The idea behind the Microsoft HD audio cert is to deliver transparent audio - and the 1150 not only does that (in theory) it's at least an order of magnitude better than human hearing.