2xalpine type x 12' subs or 2xalpine type r 15' which would be better
 

by better I mean more bass output etc Any opinions welcome thanks.

You're going to spend, what amounts to an entire setup budget for some people, on two of these subs and an amp up to the task of powering them.

I could put two 10", single voice coil, 4ohm Type E's wired in parallel for a 2 ohm load, in a properly built (and tuned) ported enclosure, on an amp that can output 500W x 1 at 2ohm - deep breath - for around $650.

Proof?
Alpine MRP-M500 $269.99 CDN @ Best Buy

Alpine 10" Type E $116.99 CDN @ Best Buy

You'll have to ask on here how much a quality built tuned box would cost to have made on this forum. But I allotted $150 for that.
$270 + ($117 x 2) + $150 = $654

You'll spend nearly double that for your Type X's. You seem to have your heart set on the big numbers associated with the X and R's. Yes, they have their advantages. But $1000 is a lot of money. Especially when its only for bass. To me anyway.

You've mentioned you want SQ is many of your previous posts. Does that much bass mean quality sound to you? What have you decided to do with your other four speakers? The ones that make most of the music?

Do you plan on competing?

Not at all and to be honest I realize i'm basically ridiculous with my numbers. I didn't realize subs accounted for 2 of my speakers though. I thought I would have to get 6 other speakers since my car fits 6 and just have the two subs in the trunk or something

No, the question about the "4 other speakers" was my mistake. I didn't consider that the Maxima has 6 speakers. A lot of bigger cars have more than 4 speakers. I just made an assumption, and was incorrect. I do wonder if the 5th and 6th speakers are actually tweeters though...
You may have a pair in the front doors, a pair in the back doors, and a pair in the rear deck behind the backseat head-rests. You should be able to find the speaker configuration for your car online somewhere.
From what I can find, you might have 6.5" speakers in all for doors, and on the rear deck...

You wouldn't have to get 6 speakers. You would get more for your money if you bought a nice pair of component speakers for your front doors, and a 2 channel amplifier to run those. Then a single subwoofer, and an amplifier to run that.

Alright, I want to help you. Lets start with your budget. How much do you want to spend?

theres no way in hell you'll fit 2 15"s in a maxima...

so with that said, if your set on alpine, buy one type X (dual 2 ohm) and a hifonics bxi 1206d amp (1200rms @ 1 ohm, overated) and i'll design you an enclosure that will make your intestines fallout @ 36hz

I really haven't decided on a budget. So far what i've sort of decided on in 3 type x sets for all 6 speakers. I'm thinking but don't know if that would be best since it would replace all 6 speakers and jalat thanks i'll pm you about that. Would you be able to do the same for a diff amp though I think I would want 2 subs and 2 amps. All is subject to change though based on what I hear

HA you do have 5 speakers in that car. 6.5 in front and rear doors. front has tweeters too. the 6.9 in the rear deck are subs :P checked it and thats what it is. you can replace them and put a 6.9 to 6.5 adapter and fit a type x 6.5" speaker. just make sure you have an amp to power all that 6channel amp or a 4channel and a 2channel

i mean 6 speakers not 5 lol

that's okay, thanks for all the help. So i'd need three amps? 1 to power the speakers and my choice of 2 to power the two subs i'm going to be putting in? And awesome thanks. I figured i'd just replace all of the speakers with type x's and throw in some type x subs as well. Well actually 4 I guess, since I can't find a 6 channel where i'm going to be getting this installed so a 2 channel, a 4 channel, and two 1 channel 1000w amps for my two subs.

Since you're made of money, how bout sending some my way. ;)

If you've got the coin. Go ape-. I would.

There are a few 6 channel amps.

Click this link >>> OnlineCarStereo

I wouldn't suggest buying anything from them. But you can browse some of the items that are available. Get an idea of what will go with what.

I'm pretty sure I saw a MB Quart 6 channel amplifier on there.