Unhappy THL W200S earphone Sound problem

Hello guys 2 days ago i bought this phone from tinydeal.com.After hours of testing i realised that the sounds that comes out of my earphones(sony zs30 music earphones and the stock handsfree earphones) is distorted on high volume .I already disabled music fx and earphone enchacer even via my Bluetooth headset Sony mw600 (a little less).Any suggestions or fixes?