[morijinal]

Somewhere I remember seeing they are supposed to push 150ohms with the built in amp, but my understanding your post is that they aren't a 150ohm amp?? Sorry, but I am confused.

 

[PurpleAngel]

Quote:

Somewhere I remember seeing they are supposed to push 150ohms with the built in amp, but my understanding your post is that they aren't a 150ohm amp?? Sorry, but I am confused.

Impedance is resistance, measured in Ohms.
The higher the impedance (resistance), the more voltage you need to overcome that resistance.
It is recommended that the Ohm rating of the headphone be at least 8 times the Ohms rating of the headphone output jack.
Otherwise you get problems like bloated bass.
 
I'm not sure the Ohm rating of the headphone jack of the Xonar DG, it might be as low as 10-Ohms, just not sure.
I've used 50-Ohm (HD558) headphones with an Xonar DG ad it sounded fine.
 
Sound card headphone output Ohm ratings.
The Essence STX & ST have 10-Ohm
The Titanium HD is 35-Ohms
The Xonar DX & D1 might have be as high as 100-Ohm
 
I've always guessed A/V receiver's headphone jack have high Ohm ratings, but there is almost zero date on that.
 
About the only headphone amplifiers that have under 10-Ohm rating are external and portable headphone amps.
 
The Xonar DG puts out enough voltage to fairly (decently) drive headphones that are 150-Ohms.
The Xonar DG can barely drive 250-Ohm headphones with the volume maxed out (so not recommended)

 

[morijinal]

Quote:

Impedance is resistance, measured in Ohms.
The higher the impedance (resistance), the more voltage you need to overcome that resistance.
It is recommended that the Ohm rating of the headphone be at least 8 times the Ohms rating of the headphone output jack.
Otherwise you get problems like bloated bass.
 
I'm not sure the Ohm rating of the headphone jack of the Xonar DG, it might be as low as 10-Ohms, just not sure.
I've used 50-Ohm (HD558) headphones with an Xonar DG ad it sounded fine.
 
Sound card headphone output Ohm ratings.
The Essence STX & ST have 10-Ohm
The Titanium HD is 35-Ohms
The Xonar DX & D1 might have be as high as 100-Ohm
 
I've always guessed A/V receiver's headphone jack have high Ohm ratings, but there is almost zero date on that.
 
About the only headphone amplifiers that have under 10-Ohm rating are external and portable headphone amps.
 
The Xonar DG puts out enough voltage to fairly (decently) drive headphones that are 150-Ohms.
The Xonar DG can barely drive 250-Ohm headphones with the volume maxed out (so not recommended)

Very informative. I know on my computer, and with my HD 558 the volume is very responsive. At only 25% it is unbearably loud! They must be doing a good job pushing the 558 because I really enjoy them. I have heard people say the bass on them is crappy, but I don't find it so at all. In fact, if I am playing Battlefield 3 with my headphones plugged into my Onkyo receiver when an explosion goes off near me they shake on my head!

 

[PurpleAngel]

Quote:

Very informative. I know on my computer, and with my HD 558 the volume is very responsive. At only 25% it is unbearably loud! They must be doing a good job pushing the 558 because I really enjoy them. I have heard people say the bass on them is crappy, but I don't find it so at all. In fact, if I am playing Battlefield 3 with my headphones plugged into my Onkyo receiver when an explosion goes off near me they shake on my head!

I do like the over all sound of my HD558, I like to think the bass on it is just right.

 

[morijinal]

I do like the over all sound of my HD558, I like to think the bass on it is just right.

from what I have noticed they really excel at natural bass, like from percussion, cello, or bass guitar. I noticed on a post from you a while back that you foam molded your 558. Did you keep the foam out?

 

[PurpleAngel]

Quote:

from what I have noticed they really excel at natural bass, like from percussion, cello, or bass guitar. I noticed on a post from you a while back that you foam molded your 558. Did you keep the foam out?

Yep, never put the black rubber tape back inside.

 

[cheelayyy]

so looks like i cant get the 558's anymore because the seller doesnt have anymore so any other suggestions? i was thinking about the ad700

 

[cheelayyy]

would the pc350 be good with the xonar soundcard i was looking at

 

[PurpleAngel]

Quote:

Would the pc350 be good with the Xonar sound card i was looking at

Was that the Xonar DG & DGX?
 
The Xonar DG & DGX are maxed out volume wise with 250-Ohm headphones.
So the 150-Ohm PC350 should be ok.

 

[cheelayyy]

okay and i might get the pc360 cause i can grab it for 140 used from dahmart
 

 

[MrMateoHead]

What I think peeps are missing is that the ASUS Xonar offers gain control as well as an impedance selector for the headphone output stage.
 
The higher gain should help with less efficient phones. So, even with the high output impedance, the board should be able to deliver adequate "loudness" into whatever phones are in use. Without knowing the actual current and voltage and what not, however, its hard to know if the board is designed to optimize power into different impedance loads. Given their warning to NOT run low impedance loads if high impedance is selected, I suspect they might alter current delivery. With up to about 1.4 watts of power from the TI Chip, I would think it is a good solution even with the high output impedance.

 

[morijinal]

Quote:

What I think peeps are missing is that the ASUS Xonar offers gain control as well as an impedance selector for the headphone output stage.
 
The higher gain should help with less efficient phones. So, even with the high output impedance, the board should be able to deliver adequate "loudness" into whatever phones are in use. Without knowing the actual current and voltage and what not, however, its hard to know if the board is designed to optimize power into different impedance loads. Given their warning to NOT run low impedance loads if high impedance is selected, I suspect they might alter current delivery. With up to about 1.4 watts of power from the TI Chip, I would think it is a good solution even with the high output impedance.

 
Speaking from personal experience - the Xonar DGX is capable of powering the Sennheiser HD 558 to ear-splitting volume. I am listening to mine right now at 12%, but usually 5%-7% is sufficient. That said, I can crank it up and I get no noticeable distortion.