I ordered a 12in fi bl with cooling and flatwind to run from a hifonics brutus brz1700.1. It will be putting out 1700rms at 1 ohm and the sub is dvc 2 ohm. I was planning on a box with the dimensions of 30x30x15 with a 2.75 in port. I was going to tune it to 34 hz so how long should the port be? Or should I get an aero port instead? I want the loudest possible setup with what i have.

If that's for a single 12 that box at 30x30x15 will be WAY bigger than needed for the sub. For a 2.5cuft NET enclosure tuned to 34hz the outside dimensions will be 30" W x 18.5" D x 15" H (assuming those were your intended width and height) with a 3" wide port.

This is more like what you're needing to look at doing.

damn my bad i ment 30x15x15 but will this give me the maximum loudness of this woofer? also would you reccomend any other amp for around this price? and i would like to know what the difference of aero ports vs slot ports?

Great sub. Had a 2.5net volume for a single one running on hifonics hifi 2500 at .5ohms was nasty for a single sub. You will love it great choice and route

You didn't post the price you're looking to buy the amp at, so it's hard to recommend you anything else at that price. In my experience it's going to be very hard to find many amps better than the Hifonics for the same or lower price unless you found something used, and you should look and consider that route. There's some really nice used equipment that comes up for sale, you should take advantage of it if there's something that fits the bill.

I think the enclosure I posted is about as optimal as it can get, and I'm sure others can chime in if they know a design that would be better. Port area can be increased which could possibly gain a little more output, but it's far too dependent on so many other factors to say with absolute certainty. Can you fit the 18.5" Depth? If not what are your maximum dimensions? We'll help you get it as optimal as possible, but I'm sure if you've never owned a sub of this caliber before you're in for a treat no matter what. Also, getting maximum loudness from the sub is dependent on many of those other factors as well, there's no way for us to say "do this and it will give you the maximum output". The maximum output is dependent on things such as the size of the vehicle it's going in, orientation, power applied, tuning, the vehicles resonant frequency, etc., etc., etc., as well as the enclosure itself. There's just no way to know what's going to give you maximum output without an SPL meter and a lot of testing.

The difference between a slot port and an aero port is pretty obvious and can easily be found and identified with a little searching on the web. To put it simply, an aero port is a round tube, like PVC pipe with flared fittings on each end. A slot port is a rectangular shaped port that is most often incorporated into the structure of the enclosure at one end utilizing the walls of the enclosure for three of it's sides typically the side, top and bottom, or in the middle utilizing two, typically the top and bottom. The enclosure I posted above is a typical slot ported enclosure with the port at one end.

i have had a 12in fi q before with a hifonics 1000 amp. I am hoping the bl on 1700 rms will be quite a bit  louder. I am in the process of getting a nissan altima so thats what il put the bl in but im not really sure if 18.5 will fit for depth? Also i wasnt asking what the ports are, i have seen both, i just wasnt sure which was louder? like what are the pros and cons of each port?

I just found this in a thread so this might help a little

Vehicle: 2006 Nissan Altima

Location: Trunk but im not sure which direction to face the sub (i will be fat matting my trunk)

Sub: 12in FI BL

Music: Rap and Dubstep

Goal: Good EQ but even better SPL

Max diminsions: 30W:15H:18D