Which is the right sub for me?

jester73 · October 31, 2012

I am upgrading my factory system (for the first time) with some Alpine components. I am looking at the Alpine MRX V70 5 channel amplifer to power SPS-610C's for the front and SPR-50 for the rear doors (for the swivel tweeters), and a single 10" sub, sealed. I listen to mostly rock.

My question is regarding the sub as this amp has 250 watts RMS on 4 ohm, or 350 watts RMS on 2 ohm. I was told to match up the RMS on the sub with the AMP, but for example many subs have a wide range in RMS like 50 - 500 watts?? Also many subs say they are 4 ohm....so does that mean I cant buy a 4 ohm sub that has more than 250 watts RMS becuse it will be underpowered? Any help or advice would be sweet!

Carder09 · October 31, 2012

Is that total power to all the components or just to the sub?

Toolman82 · October 31, 2012

Under powering a sub slightly is more preferred than anything really. You never really want to max out the sub; if you do you have a greater chance of blowing it and making it distort at louder volumes.

@ 4 ohms, your amp will stay cooler, but provide less power. @ 2 ohms it will give more power but run slightly hotter, and might decrease the amps life over time. With the Alpine being a better made amp than most, running at 2 ohms would be ok, but you may run into over heating issues in summer if the amp does not have enough room to breathe.

If I were you, I would find a 2 ohm dual voice coil sub. You will then be able to wire the sub a 4 ohms, and still have the advantages of having a dual voice coil sub. As far as power rating, any sub with a max power rating of 300-500 watts will do just fine.

I personally just bought a Rockford shallow mount 10" sub. It will mount inside of a "truck" style sub enclosure and will still provide more than enough boom.

jester73 · November 1, 2012

Is that total power to all the components or just to the sub?

just the to the sub

jester73 · November 1, 2012

Under powering a sub slightly is more preferred than anything really. You never really want to max out the sub; if you do you have a greater chance of blowing it and making it distort at louder volumes.

@ 4 ohms, your amp will stay cooler, but provide less power. @ 2 ohms it will give more power but run slightly hotter, and might decrease the amps life over time. With the Alpine being a better made amp than most, running at 2 ohms would be ok, but you may run into over heating issues in summer if the amp does not have enough room to breathe.

If I were you, I would find a 2 ohm dual voice coil sub. You will then be able to wire the sub a 4 ohms, and still have the advantages of having a dual voice coil sub. As far as power rating, any sub with a max power rating of 300-500 watts will do just fine.

I personally just bought a Rockford shallow mount 10" sub. It will mount inside of a "truck" style sub enclosure and will still provide more than enough boom.

Thank you for explaining Tim, much appreciiated!

Carder09 · November 1, 2012

Under powering a sub will.cause clipping at a higher volume. Match the rms rating with what the amp.puts out at at 4ohms or 2 or even 1 if you're that crazy lol. Also find an amp with a fan built in, good amps will usually come with them even if they are a lower power rating.