[milkweg]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif Uhm... I hope you know that the higher the Ohm rating, the EASIER it is for a device to power it. Most devices have a current bottleneck, not voltage, they like driving high impedance loads (and have to work VERY hard to drive low impedance loads)

Yes, lower impedance makes the amp work harder but also sounds louder because there is less resistance to electrical current. On EMU 0404 USB headphone amp I had to turn up the volume knob quite a bit more to get the same loudness with DT990pro compared to the setting I needed to get the same loudness level with HD595. I know about sensitivity of headphones affecting the loudness too but so does impedance.

 

[milkweg]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif 600 Ohm I think...you might wanna check the PDF on the beyer website.

That's impedance rating an not sensitivity. Sensitivity is measured in db. The higher the db the higher the sensitivity, and loudness you will get. Standard DT990pro are 250ohm but there was a 600ohm version at one time. The sensitivity of the DT990pro is: Nominal SPL acc. to IEC 60268-7> 96 dB. SPL = sound pressure level.

 

[Shahrose]

the x-fi sounds average with the DT990 Pro...i used to use that. i would have to say that it drives them to about 60% of their potential. even after you get an amp, the DAC of the x-fi will seriously limit the performance. i would definitely not recommend the X-Fi as a long term source for these headphones. just remember, loudness does not mean the headphone is being driven properly. the drivers won't be in full control and the sound will be muddy, boomy, sibilant, and congested.