Sub and amp help

[Mattimus]

Hey guys, probably been asked before but my searches never answer the exact question I'm asking.

I have my eyes set on an Alpine Type R 12" sub for my car in the near future, which has a 500w RMS and a 1500w peak (what exactly is the difference?). How much power will I be wanting from an amp to power this sub? Will I be better off bridging a multi channel amp, or going for a single? Also I'm gonna need power cable, already got the sub outputs and trigger wire wired to the rear of the car. What size cable will I be after, and what sized fuse?

Hopefully someone can help me with this, cheers.

[StoneX]

Ignore the peak/max power rating. That sub would sound best with at least a 500Wrms amplifier.

The type of amp required to run it depends on the voice coil configuration, whether it has single voice coil or dual voice coils and what impedance the coils are. It makes it much easier to help people if they specify model numbers.

8ga cable is fine for a 500Wrms amp. Most 8ga wiring kits have 60A fuses. You can use 4ga if you want but it's not necessary, I would probably go 4ga to allow for any future upgrades.

[Mattimus]

Oh sorry, there is actually 2 models of the 12" Type R, both are dual voice coil, one with 40hm + 40hm impedance, and one with 20hm + 20hm impedance. What does the difference mean? They're both the same price, one would imagine the one with the lower resistance would be better?

Cheers man, Matt.

Edit: the names of the 2 subs are 'SWR-1242D' and 'SWR-1222D'

[StoneX]

They are dual 2 ohm and dual 4 ohm. This just allows for different wiring options, neither is better than the other.

With a dual 4 ohm one you can wire the coils in series to make it an 8 ohm sub or in parallel to make it a 2 ohm sub.
With a dual 2 ohm one you can wire the coils in series to make it an 4 ohm sub or in parallel to make it a 1 ohm sub.

Once you've decided what amps you'd prefer to use, then you pick the Type R that has the appropriate voice coils.

Give this site a read to learn some stuff

[boby]

the differance with a mono block which is single channeled amp is that it will see the total impedance regardless of the number of woofers, if you have a two channel amp and bridge it the amp will see half the total impedance.
a two channel is rarely stable at 1ohm
so if you get a two channel you need to get one that has a rating of 500wats RMS at 4ohms then get the dual 4 ohm R type and wire the woofer in series giving 8ohms then the bridged amp will see 4ohms and will output 500watts. or get a amp which is 500wats rms at 2ohms then get the dual 2ohm woofer wire that in series giving 4 ohms then the bridged amp will see 2ohms so the amp again will give out 500watts.
with a mono the rating that it is at is what you have to work around.

i'd reommend:

http://www.alpine.com.au/showItem.php?item_id=78

and wiring the dual 4 ohm in parrallel

[StoneX]

I agree with boby's amp and sub recommendation

...
so if you get a two channel you need to get one that has a rating of 500wats RMS at 4ohms then get the dual 4 ohm R type and wire the woofer in series giving 8ohms then the bridged amp will see 4ohms and will output 500watts. or get a amp which is 500wats rms at 2ohms then get the dual 2ohm woofer wire that in series giving 4 ohms then the bridged amp will see 2ohms so the amp again will give out 500watts.

This is incorrect and just confusing for a beginner.

As I said earlier, a dual 4 ohm sub can be 2 or 8 ohm, and a dual 2 ohm sub can be 1 or 4 ohm. All you need to do is look at the amp ratings... If a 2 channel does 400Wrms x 1 at 4 ohm, then you get the dual 2 ohm sub and wire it in series so the sub is a 4 ohm sub overall which matches the amp. It's very simple yet people complicate it and get it wrong like above.

[Mattimus]

So if I were to purchase that amplifier recommended above, I would purchase the dual 4 ohm sub and wire it in parallel to create 2 ohm impedance? Wow so confusing :P

Thanks a lot so far guys, there has been a lot of knowledge shared so far, hopefully I can remember it all!

[StoneX]

That's exactly right

Clicky clicky

[shifty6]

the rockford fosgate site has a helpful "wiring wizard" page>>>>

Rockford Fosgate® - Woofer WiringWizard

[Mattimus]

Thanks so much guys, this is gonna help me loads when I go in to grab some gear for the car!

Cheers, Matt