1x fi spf4 18" on a 4500 watt crescendo amp. SUBWOOFER BOX QUESTIONS

[ShadeTreeMechanic]

Yeah the port will give you 5 or more db at the tuning frequency. So if you tune to 30hz then it will kill the bottom end and not be as punchy in comparison. A sealed box will give a nice flat response with a 3db roll off on the bottom end but won't be as loud. Your subs parameters will help determine what kind of box to use also.

[Kyblack76]

With that kind of power it would need a small box to stay safe. If you can build a sealed box, a slot port is not any harder. Maybe Joe X will see this. He has come up with some of the most straight forward plans I have seen.

Thanks for an actual answer bro.

Its always been my understanding ported/vented is desired for those extra few decibles and booming bass. And sealed desire for tight punchy bass?

you do want "tight and punchy" but was gonna tune to 25hz ?

im sorry dude, i have a bit of experiance with the sp4, and im kinda lost at what your goals are ?

For a sealed enclosure, i think it calls for 4-6 volume, (dont quote me) Vented is 6-8 i think. I just dont think ive ever seen a sp4 in a sealed box. Hell, do it and see what ya think.

[Mack187Murder]

With that kind of power it would need a small box to stay safe. If you can build a sealed box, a slot port is not any harder. Maybe Joe X will see this. He has come up with some of the most straight forward plans I have seen.

Thanks for an actual answer bro.

Its always been my understanding ported/vented is desired for those extra few decibles and booming bass. And sealed desire for tight punchy bass?

you do want "tight and punchy" but was gonna tune to 25hz ?

im sorry dude, i have a bit of experiance with the sp4, and im kinda lost at what your goals are ?

For a sealed enclosure, i think it calls for 4-6 volume, (dont quote me) Vented is 6-8 i think. I just dont think ive ever seen a sp4 in a sealed box. Hell, do it and see what ya think.

.

No worries brother. Experience with sp4s is what im looking for

I wanted to try a sealed box cuz ive never had one.ive had 2 12 rockfords in a ported. 2 10 kickers in a ported. And a jl dub 7 in a ported. I was curious as to what a seal would sound like. I could build it fast and solid. 4 cubic feet of spaced minimum for seal on their website.

But. My end goal would be a vented box.

Vented tuned at 25 hz for them extra 5 dbs and low freqs

[Ahmed Johnson]

I have an sp4 at about 7 cu ft tuned to 33 hz and it slams. I have a crossfire 4k amp pushing it. IT's at half ohm, I have a 370 amp alt with a northstar 220 in the back. The voltage stays pretty good and I don't smell the coil until 3 songs in going full tilt.

[Mack187Murder]

I have an sp4 at about 7 cu ft tuned to 33 hz and it slams. I have a crossfire 4k amp pushing it. IT's at half ohm, I have a 370 amp alt with a northstar 220 in the back. The voltage stays pretty good and I don't smell the coil until 3 songs in going full tilt.

Sounds like a good setup johnson. However i dont have the space for 7 cubic feet. And to my understandijg u neex less box for more power. The website calls for 6 to 7 cubic feet at 3000 watts rms. Im sending it 4500. So the box should be able to be smaller with vented or sealed am i correct?

Also of course 20 hz is pointless in many of your eyes as the sound isnt really sound at that point. But i would like to hit 25 to 26ish pretty hard with my vented box so figured a vent tunes to 25 would hit me dowbliw where i needed it. And i may add another sub amp with a hertz mille 8 or a 10" for that little bit of extra punch up high. Unless that just sounds like a good idea in my head as opposed to real life. Still extremly new to all this and doing it all myself has been extrenely rewarding(frusterating) theres still so much i have to learn

[Ahmed Johnson]

I talked to a rep from FI when doing this who told me I could go 8cu ft. at 28 hz with my power. I guess as you could do what you want as long as you are paying attention. I baby my shit, lol.

[Kyblack76]

I have an sp4 at about 7 cu ft tuned to 33 hz and it slams. I have a crossfire 4k amp pushing it. IT's at half ohm, I have a 370 amp alt with a northstar 220 in the back. The voltage stays pretty good and I don't smell the coil until 3 songs in going full tilt.

Sounds like a good setup johnson. However i dont have the space for 7 cubic feet. And to my understandijg u neex less box for more power. The website calls for 6 to 7 cubic feet at 3000 watts rms. Im sending it 4500. So the box should be able to be smaller with vented or sealed am i correct?

Also of course 20 hz is pointless in many of your eyes as the sound isnt really sound at that point. But i would like to hit 25 to 26ish pretty hard with my vented box so figured a vent tunes to 25 would hit me dowbliw where i needed it. And i may add another sub amp with a hertz mille 8 or a 10" for that little bit of extra punch up high. Unless that just sounds like a good idea in my head as opposed to real life. Still extremly new to all this and doing it all myself has been extrenely rewarding(frusterating) theres still so much i have to learn

had my enclosure tuned at 32 and smashed 24 all day, every day....... full tilt, for hours......

Edit- and your not sending 4.5k to it.....

[Mack187Murder]

I have an sp4 at about 7 cu ft tuned to 33 hz and it slams. I have a crossfire 4k amp pushing it. IT's at half ohm, I have a 370 amp alt with a northstar 220 in the back. The voltage stays pretty good and I don't smell the coil until 3 songs in going full tilt.

Sounds like a good setup johnson. However i dont have the space for 7 cubic feet. And to my understandijg u neex less box for more power. The website calls for 6 to 7 cubic feet at 3000 watts rms. Im sending it 4500. So the box should be able to be smaller with vented or sealed am i correct?

Also of course 20 hz is pointless in many of your eyes as the sound isnt really sound at that point. But i would like to hit 25 to 26ish pretty hard with my vented box so figured a vent tunes to 25 would hit me dowbliw where i needed it. And i may add another sub amp with a hertz mille 8 or a 10" for that little bit of extra punch up high. Unless that just sounds like a good idea in my head as opposed to real life. Still extremly new to all this and doing it all myself has been extrenely rewarding(frusterating) theres still so much i have to learn

had my enclosure tuned at 32 and smashed 24 all day, every day....... full tilt, for hours......

Edit- and your not sending 4.5k to it.....

very good. maybe i need to research freqs and rolloffs more.

What am i sending it?

[ShadeTreeMechanic]

A bigger ported box will have more output than a smaller ported box and both will have more output than a sealed box. Modern music will do ok port tuned to 35hz. Older music will need tuning higher or the bass will be mostly missing.

[Mack187Murder]

Ahmed and tree thanks for your replies. I will go as big as i can with ported. I may try a sealed to start just to hear what it sounds like and post my experience for everyone. Regard to your other question ahmed.

What exactly am i sending this amp and can u explain why my sub if wired to 1 ohm and the amp is 4500 rms at 1 ohm and i have constant no loss of power. Why it wouldnt be 4500?

I need to kow these things haha