I'm currently saving up money for a system but I'm kinda having a hard time deciding on a subs. My options are 4 Mach 5 MJ18's or 4 Fi SSD15's. I want a loud daily driver and I would only do local comps, maybe. They would be put in their recommended ported box and they will be run off of a SAZ-3000d when it comes out. I know the SSD's are going to be more than double the cost of the mj18's but if they're worth it I would get them. What should I do?

The two different subs have advantages over the other, but do you have the space to properly port 4 15's or 4 18's?

If yes, the MJ's don't require a monster box and can handle a little more power then ratted for, plus they have a large cone advantage over the SSD's.

For the SSD's case, they can be optioned up to your install, some giving the sub more power handling.

Both are good subs, and I have been around both. It is a decision of do you want a wow factor of 4 18's, do you want the options to customize your sub for your install? Do you like the specs of one over the other?

The two different subs have advantages over the other, but do you have the space to properly port 4 15's or 4 18's?

If yes, the MJ's don't require a monster box and can handle a little more power then ratted for, plus they have a large cone advantage over the SSD's.

For the SSD's case, they can be optioned up to your install, some giving the sub more power handling.

Both are good subs, and I have been around both. It is a decision of do you want a wow factor of 4 18's, do you want the options to customize your sub for your install? Do you like the specs of one over the other?

Well, I have an astro van so i have space for both. Other than appearance, the ssd's advantage is displacement. The options aren't important because I don't plan to ever go over the 3000 or so watts that the SAZ-3000D makes. Besides the options is the price difference worth it output wise? Does cone area make up for the lack of xmax in this comparison? Thanks.

Mj18 12mm xmax x 1,029 cm^2 = 12,348 cm^3 displacement x 4 subs = 49,392cm^3 total displacement

SSD 21mm xmax x 810 cm^2 = 17,010 cm^3 displacement x 4 subs = 68,040cm^3 total displacement

The 15" SSD's have a displacement advantage over the 18" Mj's!

But they take more power...so you could get them stock, or see if you could get them with one fewer spider (for decreased power handling).

If you wired the subs to 1ohm, you would have enough power to get them moving.

Mj18 12mm xmax x 1,029 cm^2 = 12,348 cm^3 displacement x 4 subs = 49,392cm^3 total displacement

SSD 21mm xmax x 810 cm^2 = 17,010 cm^3 displacement x 4 subs = 68,040cm^3 total displacement

The 15" SSD's have a displacement advantage over the 18" Mj's!

But they take more power...so you could get them stock, or see if you could get them with one fewer spider (for decreased power handling).

If you wired the subs to 1ohm, you would have enough power to get them moving.

First of all, you forgot to convert the xmax into cm so the total displacements are actually 4939.2 cm^3 and 6804 cm^3.

Secondly, that difference in displacement is only at each driver's xmax. Under conditions where the drivings are moving far below the xmax, the displacements could be fairly similar, or even weighted to the Mach5s.

And if you're running ported and doing SPL comps, volumetric displacement really doesn't mean much.

Mj18 12mm xmax x 1,029 cm^2 = 12,348 cm^3 displacement x 4 subs = 49,392cm^3 total displacement

SSD 21mm xmax x 810 cm^2 = 17,010 cm^3 displacement x 4 subs = 68,040cm^3 total displacement

The 15" SSD's have a displacement advantage over the 18" Mj's!

But they take more power...so you could get them stock, or see if you could get them with one fewer spider (for decreased power handling).

If you wired the subs to 1ohm, you would have enough power to get them moving.

First of all, you forgot to convert the xmax into cm so the total displacements are actually 4939.2 cm^3 and 6804 cm^3.

Secondly, that difference in displacement is only at each driver's xmax. Under conditions where the drivings are moving far below the xmax, the displacements could be fairly similar, or even weighted to the Mach5s.

And if you're running ported and doing SPL comps, volumetric displacement really doesn't mean much.

Youre right.

But I'd still go with the Fi's...

Well, he does said a loud daily driver. While the xmax would mean less at the comp around tuning, on music it could make a difference. The 3000 @ 1ohm should be closer to 8-900 per driver from what I've been told, and that would power those ssds great. I've had experience with some of Fis products, and I've been so happy with them and the service I would pay more just to deal with them.

I vote the SSDs.