TLDR

[DLHgn]

WinIsd, Bassbox pro, Torres, hornsrep, etc.

[cthedinger]

I have had success with both but I like (2) 12" better

[Quiet]

SAs get low. you will be happier with the extra cone area. Dont tune too low, though, you'll likely cheat yourself out of some dB's at best. If you do tune lower, you'll have to increase your net volume to make up for it.

[PinkFreud65]

Ok, so I don't have access to a pc, weird I know...just using my GS5 here lol. So I doubt any box sims will work on my phone. So if anyone has the inclination to "sim" a box and tuning for me.... Haha.

Can anyone recommend a good tuning then? maybe 30hz?

[PinkFreud65]

So factoring the cabin...maybe 30hz would be better?

[Rich Schenk]

2 sa 12s

[the_garynator]

I vote x15 if you want low lows or if you want to move air. Contrary to everyone siting cone area as a reason to go 12s, the x15 will actually move more air.

potential air movement (displacement) is a function of surface area & cone travel, not just surface area. While the sa12s have more cone area, it's not that much more.

2x 12s = Roughly 226sqin

1x 15 = roughly 176sqin

The outlook changes quickly when you factor in xmax.

Sa-12 = 19mm (~0.75in)

X-15 = 30mm (~1.18in)

Let's do some figures:

Sa-12s: 226 × 0.75 = 132 in^3

X-15: 176 x 1.18 = 207 in^3

Now when you consider that is only 1 way displacement, the gap increases even more.

Sa-12s 132in^3 * 2 = 264in^3

X-15. 207in^3 * 2 = 414in^3

Also, those referencing 2 coils to dissipate heat would be regarding power handling I would assume. In this case, that's a moot point since 2x sa-12s rms is 1500w, and the x15 is rated at 1500wrms.

Now if you want to do numbers the sa8s might be the better option due to efficiency and the fact that box rise at the enclosure volumes 12s require is generally less so you will probably get more power out of your amp.

Either way, I personally would go with the 15 ifI had room. Hopefully you can make a better assessment based on the information I provided, kinda depends on what you're going for. Either way I'm sure you won'tbe disappointed.

[Quiet]

if that were the case the RE XXX would be the loudest lowest sub on earth at 54mm Xmax, but we live in the real world.

Xmax matters, but it isn't the end all in SPL and sweeping air. Once you get beyond a certain point, your motor has to be able to sustain it, and the X just won't do what you think it will.

[PinkFreud65]

so....lol. I'm liking the sa 12 idea. and it seems to be more unanimous

[Triticum Agricolam]

I vote x15 if you want low lows or if you want to move air. Contrary to everyone siting cone area as a reason to go 12s, the x15 will actually move more air.

potential air movement (displacement) is a function of surface area & cone travel, not just surface area. While the sa12s have more cone area, it's not that much more.

2x 12s = Roughly 226sqin

1x 15 = roughly 176sqin

The outlook changes quickly when you factor in xmax.

Sa-12 = 19mm (~0.75in)

X-15 = 30mm (~1.18in)

Let's do some figures:

Sa-12s: 226 × 0.75 = 132 in^3

X-15: 176 x 1.18 = 207 in^3

Now when you consider that is only 1 way displacement, the gap increases even more.

Sa-12s 132in^3 * 2 = 264in^3

X-15. 207in^3 * 2 = 414in^3

Also, those referencing 2 coils to dissipate heat would be regarding power handling I would assume. In this case, that's a moot point since 2x sa-12s rms is 1500w, and the x15 is rated at 1500wrms.

Now if you want to do numbers the sa8s might be the better option due to efficiency and the fact that box rise at the enclosure volumes 12s require is generally less so you will probably get more power out of your amp.

Either way, I personally would go with the 15 ifI had room. Hopefully you can make a better assessment based on the information I provided, kinda depends on what you're going for. Either way I'm sure you won'tbe disappointed.

The problem with your analysis is that sub cone displacement is really only relevant when it comes to sealed boxes. With ported boxes maximum output isn't limited by cone excursion over much of their usable bandwidth, so the fact that the X-15 has great excursion capacity is irrelevant.