is a bigger amp rms going to kill subs

1200 rms into 800rms(pair) 1000 peak  running gain barely on going to kill my subs. Ive heard yes and no but realistically if Im not at 3/4 to  full volume would it hurt and also the amp may not be the full 12oo as the manufact claims.

What kind of amp and what kind of subs?? if both ratings are true you shouldnt have a problem as long as the gain is set properly!!! As long as the sub is not distorting you should be okay running a bigger amp, just make sure you are careful with the gain, bass boost and other settings on the amp, and with the volume, EQ and bass boost and other settings on the HU.

I've found that its far worse to underpower a sub than to overpower one. Just control the volume so you don't distort them.'85 Toy

Actually its fine and usually better to underpower a sub then it is to overpower it. It becomes bad to underpower when you are not getting the volume you want, so you turn up the volume, gain, bass boost, etc, which causes clipping. Heres a really good thread on it: http://www.caraudioforum.com/vbb3/showthread.php?t=212400

SMART use of the volume control and gains makes either "underpowering" or overpowering a moot issue. Amplifier ratings don't damage speakers. Idiotic behavior damages speakers. New Project: 2003 Pathfinder

Amp is a hifonics 1500bd I read in prior posts @ 1 ohm the guy was only getting 1090 or round abouts and I ohm which is what Im going to be running at anyways.

set gains to the level you listen to music right + 2 or 3 on the vol level?

I called Maxxsonics, who makes Hifonics, and spoke to tech support and they told me that their amps ratings are "true" RMS power. I asked several times to make sure. I even told them about Orion and how they rate their power and they told me theirs are rated the same way. "If the amp is rated at 2200 watts, you will get 2200 watts" is what I was told. Still seems hard to believe though. Their amps are sold at 1/3 the price of other top brands.'85 Toy

From what I have heard the Brutus line of amps puts out about what they say, although they need to be ran at 1 ohm to get everything out of them. For example the BD1000 puts out only 500W at 2ohm, and puts out the 1000W only at 1ohm.