I have this amp
Kenwood KAC-5204 2-channel car amplifier — 60 watts RMS x 2 at Crutchfield.com

150w x1 rms powering my 8" jl audio 8w1v2 sub in a sealed box.

I have the input sensitivity as high as it will go, however the highs from the stock speakers still overpower the lows from it, unless I have it turned up REALLY loud. Then the sub does fairly well. My question is this.

If I buy this amp
MTX Road Thunder RT250D Mono subwoofer amplifier — 250 watts RMS x 1 at 2 ohms at Crutchfield.com

125w x1 rms with a 0-12 db bass boost.

Would it be louder at lower volumes since this amp has a bass boost that I can turn up? Or would dropping 25 w rms just negate this?

Thanks for your help.

 

First off, that 25 watts will not likely even be noticeable. Bass boost is something to stay away from though, in most cases it's just not a good thing to use.

Where is the 8 located? I assume it's in the back of a blazer/jimmy/bravada, just curious.

8's are generally really not going to get as loud as larger sizes. They're pretty small and not able to move near the amount of air. Just FYI three 8" subs equal just about the same cone area as a pair of 10's. Is it the 4 ohm or 8 ohm voice coil sub? If it's the 8w1v2-8 then you're putting ~half the power you think you are to the sub and that could be your problem as the amp is rated 150wrms x 1 into 4 ohms.

You may also try it in a ported enclosure. Even the almighty Sundown SA-8 sounds very weak in a sealed enclosure by comparison. Also, this is only a 150w 8" sub, you could simply be expecting too much from it.

 

4 ohm sub. Right now the box is laying down in the cargo area sub facing up. When I mount it, it will face towards spare tire on opposite side of cargo area.

 

I wouldn't use bass boost unless you are playing classic rock and want more bass.

And stop doing incremental upgrades.

Get something decent, 500w rms at least. I recommend the RF p500-2. 2x250w or 1x 500w