[Gekko12482]

Well, so I am just taking my first steps in the world of audiophiles. I already had a Xonar DG in my pc (used it with a Corsair HS1A), and then I bought a Grado SR60i. And like many others, I immediatly liked them, but after many many hours of breaking in I fell in love with them (but damn, that took like 2 months or something). 90% of the time these things were connected to the Xonar DG. Then I got a new phone, the Sony Xperia Ray. And somehow I liked the sound getting from the phone better then that of my amped soundcard in my pc. I just told myself that could never be true and that the bass I got from the Xonar was the right amount with the right shape. But it kept irritating me for like a month, so I started a little investigation. Now I found out that de output impedance of the Xonar DG is pretty high (around 10-11 Ohms), which appears to be bugging with low impedance headphones... like Grado's indeed.. As an Engineering student I understand the full story of impedances and mass/damping/spring systems. That bass that irritates me looks like the result of having an underdamped system. I know somewhat what DAC's do, and I've got a clue of what amps do, but I have no idea how to solve this. Adjusting the gain in the drivers doesn't seem to improve the sound. I will keep my soundcard anyways, as I'm also a gamer and I need the positioning to be just right (that's what I got the soundcard for in first instance), but I also would like to have my music sound like it should, as that's the reason why I got my Grado's. So now I ask you here how I can fix this problem with the not matching impedances.

 

[stv014]

Have you actually measured the output of the DG ? I do suspect it has high output impedance, but I think the 10 Ohm value mentioned on some forums is simply an assumption based on the ST/STX for which it is known. It would be good to know the real specs, because the manufacturers virtually never release them. The impedance could even be higher, I measured 100 Ohm for the Xonar D1, and that probably also applies to the DX, and maybe the D2 and D2X as well.
 
I am not sure if the "gain" setting has much effect other than changing the maximum output voltage. If you want to fix the high impedance, you probably need a small amplifier like the FiiO E6.
 

 

[Gekko12482]

I have no idea how to measure the output impedance, but if I can I will give it a try. So the solution is 'simple' ("Welcome to head-fi sorry for your wallet"-style), getting an amplifier... Sounds pretty strange to buy an amp for a low-impedance headphone, but oh well, might need it later anyways when the headphone collection grows.

 

[stv014]

Quote:

I have no idea how to measure the output impedance, but if I can I will give it a try. So the solution is 'simple' ("Welcome to head-fi sorry for your wallet"-style), getting an amplifier... Sounds pretty strange to buy an amp for a low-impedance headphone, but oh well, might need it later anyways when the headphone collection grows.

 
Contrary to popular belief, low impedance is actually harder to drive in many aspects, although it obviously needs less voltage for the same power (i.e. a high impedance headphone will generally be quieter from the same source, but low impedance ones are more prone to frequency response irregularities, higher distortion without clipping, and high noise).
 
To measure the output impedance, you basically need some resistiors (something around 100 Ohm should be OK), and measure the voltage output using a simple sine wave test signal with and without the resistor load. From the voltage drop with a known load, the output impedance can be calculated. If you have no multimeter, the line input of the card can be used as well, but you will not be able to test the maximum voltage, and the relatively low input impedance of the card will change the result, although only by a small amount. If you have no resistors, a headphone load with a known impedance is OK as well for getting an approximate output impedance value, at a frequency where it has low reactance. Some possible problems to watch out for: make sure to avoid voltage and current clipping. Multimeters may be inaccurate at very low or high audio frequencies (the specs should include the usable range). At low frequency, a coupling capacitor on the output could affect the result, although if a capacitor is present, then it is also worth measuring, because it can roll off the bass with a low impedance headphone.
 

 

[PurpleAngel]

Trying to game with low impedance (but higher quality) headphones (using a sound card)
is not an easy problem to solve, as most amplifiers that will drive your headphones well do not provide surround sound.
The Fiio E11 might help, you could plug it into the headphone output jack on the E11 and plug the SR60i into the output jack of the E11.
You would need to keep your Xonar DG in "headphone" output mode to be able to use the surround functions for the headphones.
This setup would be called "double amplifying" which might cause extra noise in the signal.
A cmoy headphone amplifier would function the same as the E11.

 

[Gekko12482]

I don't really care about the quality of the sound ingame, I just want some good surround sound (that was the reason the Xonar was bought), but now I also would like to get some better SQ out of my pc when listening to music. So when I need the great SQ I don't need the surround effects, and the opposite way is also true. So the best thing I can do is getting a FiiO E6 or E11 and connect to the onboard sound solution to prevent double amping? (Or just connect it to the Xonar, but use the 2nd setting?)
 
(Someone ever posted) "Doesn't the DG allow one to select between three settings for headphone output?
<32ohms
32~64ohms
>64ohms"
 
(Reply) "The first one is actually a low volume setting, the second a high volume setting, and the third one is a higher gain setting. Output impedance doesn't change."

 

[stv014]

Quote:

So the best thing I can do is getting a FiiO E6 or E11 and connect to the onboard sound solution to prevent double amping?

 
Generally, you want to connect the amplifier to whichever source gives better quality. If the DG is better than onboard audio even with "double amping", then obviously choose that. By the way, the newer onboard chips also have amplified output, it is just not very powerful, and the amplifier (buffer) can be disabled (this increases the output impedance).
 

 

[Gekko12482]

Okay, thank you all for your help, I will get some FiiO amp then very soon
 
(If I meet up with my uncle again, I might do that output impedance measurement, I'll post it of course if it succeeds )

 

[Mr.Sneis]

Not going to lie, the analog out of my DG is not exactly audiophile quality imo; I'm not even sure if it sounds better than my onboard.
 
Go external DAC with amp or all-in-one dac/amp is my best recommendation.
 
I use my DG because I couldn't get the mic out of my onboard to respond; and it's mic performance thus far has been very disappointing.