GOOD 6.5' FRONT AND REAR SPEAKERS?

SO I HAVE 2 15' KICKERS L7 WIRED DOWN 2A KICKER ZX2500.1 AMP ON MY INFINITY Q45....I HAVE FRONT AND REAR 6.5' ALPINE TYPE S SPEAKERS (TOTAL 6). THE SPEAKERS ARE NOT LOUD ENOUGH AND CERTAIN SONGS YOU CAN BARELY HEAR VOICE. LONG STORY SHORT I NEED MORE VOCALS...DOES ANYONE KNOW WHAT 6.5' FRONT AND REAR SPEAKERS ALONG WIT AN AMP WILL BE GOOD AND LOUDER FROM WHAT ORIGINALLY I HAVE???.....I REALLY DON'T HAVE A BUDGET, AS LONG AS THE SPEAKERS ARE GOOD ENOUGH AND AMP TO SOUND COO WIT MY SUBS IN ORDER TO HAVE VOICE..