philbert

Do you already have the sub, or are you purchasing a new one?

I was somewhat mistaken before, not realizing that there are two different options for the Type-R subs: dual 2ohm voice coils or dual 4ohm voice coils.

If you want a 2ohm load for the kicker amp, then buy the dual 4ohm sub, with the VCs run in parallel. If you get an amp that runs better with a 4ohm load, buy the dual 2ohm sub and run in series.

As to the components, when they present a RMS or peak power rating, it's per channel.

SEA2SJK

Yeah, I'm getting Alpine SPR 17s.
It's 110 rms watt but I'm not sure that means 110 rms watt x 1 or 110 rms watt x 2. I'm thinking about getting Alpine MRP-M300 amp which would give the speakers 150 rms watt x 2. I just want to make sure so I don't blow up the speakers in case...

SEA2SJK

You the man philbert. I really appreciate for your help.

I haven't bought the sub yet, but i'm pretty sure I'll get the 12" type r.

Why do I need 4ohm sub for 2ohm load?

How about Alpine-M500 for the sub and Alpine-f300 for the speaker?

I think this set up wouldn't overload both amps and speakers.

philbert

looking at the alpine website, there are two 12" type-r subs:

SWR-1242D (4Ω + 4Ω) or SWR-1222D (2Ω + 2Ω)

these are both dual voice coil subs (see link for more explanation):
http://www.crutchfield.com/S-PMjXb8B3X9W/l...ofers_dual.html

a traditional single voice coil sub is easier to think about: if it's listed as 4Ω, then you look at amp power ratings at 4Ω.

a dual voice coil sub is in way like adding two separate speakers, though there is only one cone. the main reason speaker makers do this is to increase flexibility when adding multiple subs, as you can choose to wire each pair of voice coils in parallel or series in order to get the desired total impedance.

when you are only adding one sub, and it is only available as a dual voicecoil, then you have to consider the total impedance of the speaker given the two wiring options.

so, the total impedance of the SWR-1242D can be either:
8Ω in series (4Ω + 4Ω) or
2Ω in parallel [(4Ω * 4Ω) / (4Ω + 4Ω)]

similarly, the SWR-1222D can be either:
4Ω in series (2Ω + 2Ω) or
1Ω or parallel [(2Ω * 2Ω) / (2Ω + 2Ω)]

i think those two alpine amps could work well. in that case, i'd probably go with the SWR-1242D, wired in parallel, so you'd have 500 watts at 2Ω.

SEA2SJK

Thanks philbert.
I would buy wrong type of sub but you helped me out.
Then I guess I'm all set deciding my set up.
I have to study how to install the system now.