Can Anybody Help?????

Alright. I have 3 kicker cvr's and a kenwood 1800 watt mono amplifier in a 1995 mustang. If i wire the subs to 2.66 ohms the sound quality is great. but ill turn the volume about half way up on my radio, and my battery hand will drop to 8-9 volts everytime the subs hit(even when im driving at 2000 rpms). and if i turn the radio up anymore the amp will quit sending power to the subs. but the amp doesnt cutt off. ill turn the radio back down to about half way and it will cut back on. but if i wire the subs to 6 ohms, i can turn it all the way up and the battery hand wont move. but then again the subs dont hit hard enough to hear the bass. so i guess my question is why when i wire it to 2.66 ohms does it drain my battery. and what can i do to fix it? Any information would be great.  

Because in most all cases, the lower the impedance, the higher the amp output. The higher the amp output, the more the current draw.