Just recieved my whites jvc400, right out of the box these are lacking some sparcle/highs compared to my coworkes s400 with over a week of use/burn in.
Same thing that i didnt like from my s500 with less than 50hours of burn in, they where lacking some highs and i had to use the treble boost from my ipad.
In any case, $30 bucks is just a bargain and they sound very good.
Also my papertowel mod wore out as they flattened with use,
so I now using those long brown paper towels, folded up long ways , then cut extra length .
Now they are more lifted very nice sounding