15" Fi Subwoofer Box opinions!!!

[Tjwubs34]

Hey guys just need someone to quickly look over my box. I got a 15" fi sp4 coming in a few weeks want to get a box built over the weekend. I want to go for the lows as best as i can around 25hz to play, and want to hit the highs decently. Gonna be running soundqubed 3500 at .5 ohms on stock alternator for right now... most likely a 370 amp alt from either mechman or singer (need opinions on that). So far here is my box build specs from TORRES

Some of these dimensions are max space i drive a hatch back and dont want the box to be too tall. I can go as high as 18H, 39W, 30D...

i have to keep my depth around 25-26 to allow the port to breathe.

Heres my torres specs

17H 39W 20D

Port height: 15.5 Port Width: 4.5 Port Depth: 37.... ( going for an L bend)

I will have the subwoofer on top, port facing the hatch since it is a hatchback...

Here is the displacement specs

1 Extra baffle

Woofer displacement: .21

Bracing: .05

Baffle thickness: .75

Port thickness: .75

Common walls: 3

Box stats overall

Port Area: 69.75

Port Area per foot: 16.62

Net Volume: 4.20 ft^3

Tuning: 31.48 HZ

Any feed back would be great:)

[dolarbilz]

Please upgrade alt before trying run amp at .5, and why do you need it at .5 and how many batteries do you have now?

[Smoove]

These numbers look great

Port Area: 69.75

Port Area per foot: 16.62

Net Volume: 4.20 ft^3

Tuning: 31.48 HZ

SSF 24hz <-------

As stated already. Running .5 on stock electrical is asking for something bad to happen.

[Tjwubs34]

These numbers look great

Port Area: 69.75

Port Area per foot: 16.62

Net Volume: 4.20 ft^3

Tuning: 31.48 HZ

SSF 24hz <-------

As stated already. Running .5 on stock electrical is asking for something bad to happen.

i could run on 2 ohm but the sub is a D1. And after box rise etc... it will be more like a 1 ohm load. and i will be using low gain, possibly a dd1 to properly set gains. My stock alt is 150 amps so its not like its a bad alt

[dolarbilz]

The alt is probably 150 amps on a good day..that's enough power to run your stock electrical.now you will be throwing at least 300+ amp draw on top of that..and how many batteries do you have now to back your amp? Which your alt will have to charge as well.best to run at 2ohm even then you are taxing your electrical system.going to make amp work hard sooner or later poof!

Not down playing what you want hope you realize what's really happening here..I wouldn't put that amp in until electrical up to par

[Smoove]

These numbers look great

Port Area: 69.75

Port Area per foot: 16.62

Net Volume: 4.20 ft^3

Tuning: 31.48 HZ

SSF 24hz <-------

As stated already. Running .5 on stock electrical is asking for something bad to happen.

i could run on 2 ohm but the sub is a D1. And after box rise etc... it will be more like a 1 ohm load. and i will be using low gain, possibly a dd1 to properly set gains. My stock alt is 150 amps so its not like its a bad alt

when you say 150amp alt. Remeber the vehicle can use 50-90amps of that so you dont have 150amps for the amp. And that 150amps might be at 6000rpm. So you dont really have 150amps of useable power.

[Guest]

any advice?

strive for quality bracing, your box is going 2 need it.

I have a 15" sp4 too, u should run it @2ohm

that shit was hammering at 2ohm at 1200watts b4 i got my bigboy amp

Clean 2ohm is better than dirty .5ohm but thats just my opinion

Your location is not listed so Im not sure but if youre close 2 me Id sell u my SP4 box

Im in cleveland ohio

[Tjwubs34]

Yeah i will prob run at 2 ohm for now and the gain knob from soundqubed should tell me if i am clipping. And yeah im from detroit michigan but i wanna build my own anyways. I use threaded rod bracing. My last car used a 90 amp alt and i ran a 3k amp at 1 ohm decently got down to 11 volts. This car is alot more i have never really ran a big system with it yet. I will be getting that 370 amp alt soon though

[3vil]

You ran a 3k amp, but you definitely weren't seeing 3k watts on that electrical.

And I personally don't trust an LED on a gain knob to tell me when I'm clipping. If it were that simple the DD-1 would be in a much smaller package.

[Tjwubs34]

You ran a 3k amp, but you definitely weren't seeing 3k watts on that electrical.

And I personally don't trust an LED on a gain knob to tell me when I'm clipping. If it were that simple the DD-1 would be in a much smaller package.

I asked soundqubed about their clip indicator on their gain knob and they said it is up to par with a osciloscope. I asked them if it measures the sine wave they said it does.... so its pretty damn accurate!!!