ART USB Dual Pre Audio Interface as Headphone Amp?

[Jcat4]

Hellooo all, long time lurker, first time post..er. I am currently in possession of a pair of KRK kns8400 Headphones and have been using a ART USB Dual Pre Audio Interface that I use for my mic as a headphone amplifier. I was wondering, how bad of an idea is this? Or is it a bad idea? I can't really tell if there is much of a difference between the audio interface and just a raw input from my laptop (desktop is broken, yay RMA's..) other than volume. I checked the specs on the interface and realized the frequency response is 20 Hz to 20K Hz, while my headphones go from 5 Hz to 23K Hz. It seems I am losing a tid bit of sound in those frequencies. I've heard many people say "Well since the human ears can olny pick up 20 Hz to 20K hz, the rest doesn't matter blah blah" while others claim it does?  Sorry to ramble, but my main question is this: Is it a huge loss in SQ, if any at all, to use this Audio Interface as a headphone amp? Thanks!

 

[Jcat4]

bump

 

[Jcat4]

bump

 

[Armaegis]

You're not missing anything in the frequency response. There's no "information" there to lose, and nothing is ever recorded in those extremes anyway. 
 
As a headphone amplifier... meh the specs aren't that great. The gain isn't very high and the output impedance is wretched which will muck with power available and low end response. If you don't know what that means, don't worry about it. The sound via usb might be marginally better than directly off your motherboard, but the amplifier is going to be a limiting factor. 
 
TL;DR... if you aren't using a mic, it'd probably be simpler just to plug directly into the laptop. 

 

[Jcat4]

I kind of get what you're saying. Since my amp is running through usb and even seen by windows as a separate output, does that mean it's technically running as a DAC, too? If so, I suppose that would be better than my onboard laptop soundcard that I really don't know much about. BUT the amp part of it with its low gain is what would essentially screw up the headphones by mucking up the bass response?

TL;DR If the interface sucks, what kind of amplifier would be of recommendation for preferably ~$100?

 

[Armaegis]

Assuming you're outputting through the ART, yes it's being used as a DAC. 
 
Low gain isn't that important unless you have inefficient headphones. For most headphones, low gain is probably preferable. The more important parameters are distortion, high&low rolloff, output impedance, power filtering, etc, I don't know any of those about the ART though. I only know it has a lowish gain and terrible output impedance.
 
As kind of a general rule though, if you're satisfied with the sound, then don't go spending any more needlessly. It's really a big game of diminishing returns. If you'd like a simple budget usb dac/amp, the FiiO e10 is a nice little unit.