Ohms mismatch or other problem?

[kafelnikov]

Hi there,
I am about to order a new pair of headphones and I was wondering if you could help me with a problem I have had for quite some time with my soundcard (Presonus Audiobox USB), I use the audiobox only with my speakers because when I plug my headphones in they sound like total crap (which it doesn't happen when I use them with the integrated realtek soundcard inside my laptop, they sound beautiful there), basicly it sounds like there's a sort of high pass filter that completely ruins the sound, giving it a sort of harsh ''electrical'' quality to it, and losing all bass of course. I had posted about this problem in the presonus forum actually some time ago, this is the thread if you want to read about it: https://forums.presonus.com/viewtopic.php?f=164&t=7100&sid=9a98d2416120eae9ce269236fb9355d7
 
As you can see a guy there suggested me that it was likely a ohm mismatch between my headphone (32 ohm) and the headphone amp of the audiobox (those are the specs of the audiobox headphone amp: 60 mW/Ch @ 60Ω Load)  that caused that hpfilterish sound. I was wondering if you think this is the root of the problem and that if by ordering headphones with a higher ohm impedance than 32 ohm that would solve the problem.
 
thanks for your attention
cheers

 

[NA Blur]

The noise could be coming from the USB interface as many poorly designed USB amp/DACs do not isolate the USB noise. Not having the actual output impedance of the amp/DAC does not help either and I cannot find it on their site. The 60 Ohm number you see is the measured output using a headphone / load that is 60 Ohms and does not tell us about the output impedance.
 
If you have the headphones plugged in and the volume set to zero, no music playing, can you hear the noise?
 
Be sure to check here:
 
http://support.presonus.com/entries/21530545-My-AudioBox-is-producing-or-recording-noise-What-do-I-do-
 
I think the simplest solution is to assume the USB power / grounding is the source of the problem and a powered USB hum should completely cure the issue.

 

[kafelnikov]

Thanks for replying but the problem is not ''noise'', the soundcard is fine, doesn't produce any noise whatsoever. The problem is that the headphones sound like there's a high pass filter applied to them when I use them with it, the bass is pretty much gone. It sounds harsh but not noisy. And the sound signature of the headphone is not harsh at all when used with other sources, they sound great and balanced with other sources. 

 

[NA Blur]

Try uninstalling the driver and then installing it again and see if that helps.