[rahuldagli]

I am currently using onboard realtek sound card with Fischer audio silver bullets IEM. It has low impedence of 18 ohms so I guess it doesn't require much powerful amp to drive. But there is a lot of buzzing noise coming from onboard sound card. So I am looking for an upgrade. Budget is not an issue. I have shortlisted 2 sound cards Asus Xonar dg and Asus Xonar st. I know there is lots of price difference between them. But is xonar st significantly better over xonar dg worth the price?
 
Here's my IEM silver bullets specs:
Frequency range: 12-22000 Hz.
Sensitivity: 102 dB.
Impedance: 18 Ohm.
Input power: 60 mW.

 

[skamp]

Xonars (and most PC soundcards) have high output impedance, which means they can't properly drive low impedance headphones, much less IEMs. You need something that has an ouput impedance of 2 ohms or less, like the FiiO E7 (high quality DAC + integrated amp). Or you can buy a Xonar and plug an amp into them (like the FiiO E5).

I'm sorry I can't recommend more products, because few have their relevant specs listed, and few are independently measured… The sad truth is, few have outputs that can properly drive low impedance headphones.

 

[PurpleAngel]

18-Ohm IEM and Xonar sound card in not a good match.
Better would be the Fiio E10, USB/DAC/Headphone amplifier.
 
If you want surround sound for movies or gaming.
Then get the Xonar DG with the Fiio E11 amplifier.

 

[rahuldagli]

Quote:

Xonars (and most PC soundcards) have high output impedance, which means they can't properly drive low impedance headphones, much less IEMs. You need something that has an ouput impedance of 2 ohms or less, like the FiiO E7 (high quality DAC + integrated amp). Or you can buy a Xonar and plug an amp into them (like the FiiO E5).
I'm sorry I can't recommend more products, because few have their relevant specs listed, and few are independently measured… The sad truth is, few have outputs that can properly drive low impedance headphones.

Do I need amp in reality or DAC is just enough for for low impedance iem?
 

 

[skamp]

If your onboard sound card is noisy, you need an external DAC (or a sound card with proper isolation from PC noise). A DAC serves the same purpose as a sound card.

As for the output impedance issue, you need an amp with < 2 ohm output impedance. You can get a product that's a DAC with an integrated amp. The FiiO E7 and E10 fit the bill. Or you can get a sound card (Xonar or whatever), and a separate amp with the specs I mentionned.

 

[stv014]

I am not sure if this graph is reliable, but if it is correct, then output impedance does not actually make that much difference with these particular IEMs:
 

 
However, they are very sensitive, so a low noise floor is important. In that aspect, almost anything is likely to be an improvement over onboard audio. For low noise, the Xonar D1 would be very good, but it does have 100 Ohm output impedance (which in fact makes the noise even lower, less than 1 uV A-weighted). The DG is cheap and definitely better than the onboard, so it may be a good choice from the sound cards. The Essence ST is an overkill, and noise level is actually not a very strong aspect of its headphone amplifier. For low output impedance, any device made by FiiO with the exception of the E9 would be better than than any of the Xonars; I would recommend the E10 for use with a computer only (not portable).
 

 

[skamp]

That graph only shows the impedance of the IEMs…

 

[stv014]

Quote:

That graph only shows the impedance of the IEMs…

 
Yes, but large impedance variation over the frequency range (such as on the graph below) is the main source of audible changes with different output impedances, and the lack of it also suggests that the driver may not rely much on electrical damping. Of course, low output impedance is still preferred, but it is less likely to make a "night and day" difference.


 

 

[skamp]

In any case, he better buy something that he'll be able to use with different IEMs/headphones, should he decide to buy new ones in the future.

 

[rahuldagli]

Will Fiio e11 + xonar dg be a good combo? Since I have heard that inbuilt sound card have better dac compared to similarly priced usb dac. And I have also read few article where it was mentioned that amp are not at all necessary for IEM's with low impedance since they require less power to drive. Which can be easily driven from ipod or iphone. And adding amp will make no or marginal difference in terms of SQ. Is that true?

 

[PurpleAngel]

Quote:

Will Fiio E11 + Xonar DG be a good combo? Since I have heard that inbuilt sound card have better DAC compared to similarly priced USB DAC. And I have also read few article where it was mentioned that amp are not at all necessary for IEM's with low impedance since they require less power to drive. Which can be easily driven from iPod or iPhone. And adding amp will make no or marginal difference in terms of SQ. Is that true?

I think the Asus Xonar DG + Fiio E11 is a nice combo, I tested that combo about 3 weeks ago with about 5 different headphones.
Motherboards with built-in sound cards usually come with very low cost DACs
Sound cards are considered to have better DACs then what comes in motherboards.
You can send hundreds of dollars for a really great external DAC.
Xonar sound cards come with a high impedance, which is no problem for headphones that are 80-ohms or higher.
I'm fairly sure the Fiio portables work better with 18-Ohm IEM/Headphones.
 
If your will to spend a few more dollars, the Xonar DX/D1 comes with a better DAC then the DG,
The DX/D1 do not power headphones as well as the DG, but the as long as your getting the E11, that really does not matter.