If a USB cable doesn't meet the specifications, the result would be 1 of 2 things:
1) the audio is unchanged
2) data errors are introduced, which may or not be audible. if this were a video cable, you would see the errors, because eyes > ears. which is why every HDMI cable is made the same way, you can't ignore the physics of it and just braid wires together.
The possibility of improving the sound never exists, unless the data errors are magical. But I guess that's enough to still need a 3rd possibility.
3) Lost or misinterpreted 0's and 1's result in added bass, added warmth, bigger soundstage, take your pick.
You know what would make a difference...for that kind of money, you could probably get a box that optically or transformer isolates all 4 wires from the computer and reclocks the data, and uses a battery to supply the 5V to the device.