OK. My sub i s a jl12w3v34 with 500RMS at 4OHM
Should I go with the Alpine mrp-500, or KAC-9104D.
Both I can get for the same price.

 

Looks like the Kenwood is the louder amp. Not sure how accurate their ratings are ... and the fact it reports to be 1 ohm stable is a plus. Should heat up less. It's also rated at 500rms at 4 ohms. Similar to your W3v3.

 

is the sub dual 4 ohm or dual 2 ohm or that JL signature 3 ohm/1.5ohm

 

Single 4 ... pretty sure.

 

YA its a single 4ohm.
Rated at 500RMS

 

jl audio amp

 

His choices are good ones .... much cheaper than JL amp .... The Kenwood looks alright. 500 rms at 4ohms. If he adds another sub later he's set!

 

k. Thanks. looks like i'll go with the Kenwood.

 

Be sure to use that SSF if going ported.

 

I would not go with either, unless you're planning to grab a different sub later on. This way you'd be wasting either amp's full potential. If I was keeping this sub, I would grab an amp that is designed to do full output at 4 ohms, which pretty much locks you in for a 2-channel amp, as a mono option would have to have a regulated power supply and thus be more costly. If you were grabbing another one of those subs and running them bridged, that would mean you'd need a 2 ohm stable amp, and I'd be looking at an amp capable of doing full power at 2 ohms. Both your options will do, only the Kenwood has more power, and it is stable down to 1 ohm, and it is regulated to do same power at either 1 or 2 ohms, so really a no-brainer here - Kenwood wins. Even with your current set-up Kenwood is a better option. So Kenwood wins everytime. The choice is obvious.