2 caps - parallel correct?

[94tegRS]

well, I got it at 4 ft^3 total with 2 drivers, and 2 3" ports tuned to 26 Hz the gain and group delay look pretty good to me. now mine doesnt tell me vent mach cuz I dont know the Pe. what is that? will only 2 3" ports in a box wiht 2 12's recieving 1200+ watts make alot of port noise?

also I dont have Z or BL.

Z says its measurement is ohms so i figured maybe the resistance of the sub but Re is ohms as well and 5.4 and its advertised as DVC 6 ohm so i figured that was that.

Pe is watts I am guessing cuz the measurement is just W which i think might stand for watts but I will never have the same amount going to the sub and dont even know exactly what I am gonna be giving them so it cant be that. another thing about xmax, this is the excursion limit right, so if audiobahn says +/- 14mm, I entered 28mm total. was I right. I also attatched the gain and GD chart for you to look at.

[Haibane]

the only thing I can help you with is, I think that xmax is only one way, so audiobahn is just saying that it has an equal in out max. Just a thought, not quite sure, could look it up but don't feel like it. Audiobahn has a list of terms on their site if you want to look at it.

[94tegRS]

well, I changed that spec and it didnt change ythe gain plot or the group delay plot at all. I also put 1000 in pe cuz audiobahn says pe is the rated RMS power handling and I have a port mach of .13 and it is green so I think im fine there. z says total resistance but I still dont get it. each coil is 6 ohm so is it 6, 3, or 12???

[94tegRS]

I couldnt upload them since they were bmp, sop i got a image converter and changed them to jpg but they are too big. anyone else wanna look at them and give me some help tell me and Ill email them to you.

[Haibane]

Total resistance, yeah, where is gsteg when you need him, some of those specs bug me, I would say it is probably 3 ohms but I could be wrong.

[GSteg]

Don't worry about BL or Z. They do not influence anything on box. What does affect the subwoofer's need for box size is the Qts and Qes. There are other things that take into account, but not necessary too important. Usually I look at the Qts and get a general idea if the sub needs a big box or a small box.

Pe shouldn't matter because thats the thermal rating of the coil; how much power the coil can handle before it goes kaboom.

Z is the impedance, but most likely you'll see changes on the impedance graph.

And yes, thats why some people prefer SQ of a sealed box over a ported box because usually, the ported box is not designed correctly and you have a huge peak, right near the car's resonant frequency. Thats why it's boomy because the resonant of the system combined with the resonant of the car gives off that exaggerating bass, and our ears/brain process that as boomy.

Tuning to 28hz is a great start. Thats what I would do for SQ purposes. Don't worry too much about the graph on WinISD. Thats only an anehoic response, which means nothing in a car. WinISD assumes everything is perfect and you're in an open environment (ex: out in the opening).

The Xmax is not the limiting excursion of the woofer. Xmax can be defined in many definition. Some will use the overhung method or the underhung, depending on what kind of subwoofer it is. Some will say xmax is 70.7% of the rest BL, or peak BL. But it shouldn't affect the box at all.

I think the port you have right now should be ok. Just tune it pretty low and you'll be fine. As far as port noise, I have no idea. I rarely make my ported box with those circular ports, and when I do use them, It's usually for home audio midrange/midbass speakers.

[94tegRS]

would a rectangle slot port be better?

I am one of the people who isnt doing this all for my enjoyment, some of it is to show off how loud my system is. I am sure though if one high excursion in 3.5ft^3 ported off of 500 watts was loud enough for me, 2 alum12q's in 2ft^3 off of almost 1400 watts should cut it, even tuned lower.

[GSteg]

is it 2.0 cubic feet per driver or for both subs?

[94tegRS]

yeah, total box is about 4.7 ft^3 which when the subs and ports displacements are figured gives them just over 2 ft^3.