sub in ported box

[kman]

so i have a crv 10in kicker in an xed ported box i was just wondering why the sub is louder when the door opens or the windows are down

 

[BlueChariot]

Scientifically speaking I don't think it COULD be louder with the door open, due to the fact that with it closed, the soundwaves are contained and bouncing around the cab. When it is open, sound escapes.

It may be a bit of an audible illussion due to the difference between the air pressure of an enclosed cab vs an open one. Think of it like ported vs sealed box.

 

[PFM99]

every car that iv ever put on the b n k has been louder with windows up because the windows keep in the air pressure but they sound louder with windows down something to do with changing the rf of the car

 

[powerranger262]

Mine is waaay louder with all the windows open.

 

[PFM99]

well if you get a bnk or term lab and show me numbers then you will prove my years of working in a streo shop wrong

 

[powerranger262]

Probably because my box is sealed.

 

[Jason]

You could also have the sub in a box too small for it, then the release of pressure, albeit minute, helps it work better.

 

[littleme13]

for those of you that claim its louder with the windows down are you referring to outside the car sound or in??

 

[powerranger262]

Inside, but I bet you wouldn't believe it's also louder outside when the windows are down.

 

[kman]

i know its louder out side when the windows and it is louder inside the sub hits hard once you open the door and its louder i know the box is big enough for the sub to

 

[Ranger SVO]

i know its louder out side when the windows and it is louder inside the sub hits hard once you open the door and its louder i know the box is big enough for the sub to

And in most cases you are correct. I'm assuming that many that responded to you have not graduated High School yet, or they failed basic physics. The reason this happens has to do with the length of the low frequency wave.

An 80Hz wave is about 167-inches long, a 60Hz wave is about 223-inches long and a 40Hz wave is 335-inches long. In any case these low frequency wave can not fully develope in the confines of a Ranger interior.

So when you open a window or door it will get louder.

For those of you that think my lengths of the wave are wrong, I rounded the Speed of Sound to 13400 Inches Per Second. So, yes, I can be off one or two inches.

 

[littleme13]

this was were my point was headed. many people fail to realize that there is more to subwoofer choice then box size and design. i call it free air space, not sure on the technical term, but its the air space the subs have to move out side the box. this is why suvs and vans have better sound and are generally louder then pickups, hatchbacks also benifit from this as the trunk isnt as restrictive. subs need the airspace in front of them as well to create sound and with out it the are just as restricted as placing them in too small of a box.

 

[powerranger262]

And in most cases you are correct. I'm assuming that many that responded to you have not graduated High School yet, or they failed basic physics. The reason this happens has to do with the length of the low frequency wave.

An 80Hz wave is about 167-inches long, a 60Hz wave is about 223-inches long and a 40Hz wave is 335-inches long. In any case these low frequency wave can not fully develope in the confines of a Ranger interior.

So when you open a window or door it will get louder.

For those of you that think my lengths of the wave are wrong, I rounded the Speed of Sound to 13400 Inches Per Second. So, yes, I can be off one or two inches.

this was were my point was headed. many people fail to realize that there is more to subwoofer choice then box size and design. i call it free air space, not sure on the technical term, but its the air space the subs have to move out side the box. this is why suvs and vans have better sound and are generally louder then pickups, hatchbacks also benifit from this as the trunk isnt as restrictive. subs need the airspace in front of them as well to create sound and with out it the are just as restricted as placing them in too small of a box.

Kind of took a long road to a short point there guys. Obviously that's why it's louder when open, my 30year old physics class passing brain didn't have to think that hard about it.

 

[kman]

thanks for explaining it i understand it more now and know why its like that thank you ranger svo