okay well first of all i found this site and read alot of very useful info. Some of u guys on here are wizards but anyway thats what brings me here.  Ive done a few installs of my own and know more or less what is going on with subs but i have run into a problem with my current setup. I currently run Two alpine type r 12's swr1242D speakers 4ohm to a hifonics BXi1208D 2400 watt super class-d monoblock amp.  I have a cap but i forget which brand it is just cuz i bought it back in highschool i know its 1 farad though. As of right now my speakers sound loud inside the car. Outside though they are a little weak at least from what ive seen on on youtube it dosent look like my speakers move as much as theres.  I followed the wiring diagram that came with my subs and they fire up but i still dont think there are being pushed to the limit. I have them in a sealed box 31' width 15' high and 17' deep.  Is my box to small or can i wire them differently.

current wiring

Any help is appreciated. Thanks

That is a 1200 watt amp.  You can run it at 1ohm though to get the most power out of it.  The type r's should take all that amp can throw their way.  The amp does need to be set properly to avoid overdriving it which could lead to blowing your subs. 

The type r's will be considerably louder in a custom ported box designed for those speakers. 

To achieve a 1 ohm load to the amp, just run each individual coil directly to the amp.  The are dual 4's right? 

You can run the positive from each coil to the positive on the amp. Then the negative from each coil to the negative on each amp. 

Your amp is internally bridged, there is just two speaker outputs.  Kinda looks like two channels, but they are connected inside. 

I can't view your pics on my work computer.  How exactly do you have everything run now.  Your two options should be 4ohms at the amp or 1ohm at the amp.  Which should mean you have the negative from one coil running to the positive on the other coil then to the positive on the amp. The other side positive running to the negative coil then on to the negative of the amp.  This sound right?  I don't know how to add diagrams, and I'm not sure my computer will let me anyways.

Wiring at 4ohm will get you somewhere around 300-500 watts.  Wiring at 1ohm should get you closer to 1000-1200 with that amp.  The hifonics are a lil overrated but these numbers are prolly close.  A good ported box will probably make a much bigger difference then just changing the impedence shown to the amp. 

Also running at 1ohm, the amp will have higher distortion and will run much hotter. 

when u get a chance just take a look at the diagram i posted up. Its from alpine and i have it currently wired the way it is in the pic. I just want to be sure and not fry my speakers when rewiring this if it needs rewiring.  And i was thinking of building a new box and porting it But im not sure if it will all fit in my trunk. Either that or just building a box with a port for one speaker and seeing if its any better or clearer on the high notes.  Which direction should i head in?

The link above I posted shows the two ways to hook up your speakers.  Yours should be hooked up at 4 if you are correct.  If you would like to drop them down to one, just check the diagram and it will show you how. 

Do you have room to put a box in that is any bigger than the one you have now?  I think the type r's perform well in somewhere around a 2 to 2.5 cu ft chamber.  I'm gonna guess tuning low 30's.  Your box now is around 4 which means you might be able to build a ported box with a similar footprint.  A little bigger would probably be better though. 

Haven't played with the type r's too much.  Try doing a search on the forum and see if that helps.  I believe anzboi works with the alpine stuff a lot.  You might send him a pm to see if he might help design an enclosure. 

edit: my thoughts exactly.  I can help you lay this out if you wanna try to do it yourself.

https://www.the12volt.com/installbay/forum_posts.asp?tid=115091&KW=type+r+12+ported