Okay, so my brother wants me to build his box for him in his 86 MR2..he wants the sub up front, and the only way i could see doing this is to extend the port outside of the box through what is normally the firewall into the passenger compartment.
i am not sure about lengths yet as i havent got into measure it up yet..i am just trying to figure out the best way to port it, so he can hear it in the car.
so my question is,
1>how do i calculate the length of the port if it extends out of the box?
1a>does it even matter? now i realize the port's thickness would normally be subtracted from the volume of the box for more accurate numbers.
2>now if i need a port say 15 or so inches long, is it going to make any difference if only 3" is inside the box and the rest is outside of the box?
3>will i have to include the volume of the port outside the box in the volume of the box calculations, when i go to build the box?
thanx for your time and help guys.
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Fiberglass Guru.
1) same as always, it doesn't matter.
1a) yes, you still have to account for any material inside the enclosure.
2) no, that's fine.
3) no, only the portion that actually takes up space inside the enclosure.
Now here's my question: if I understand you correctly, you are building a system ported into the cabin, but the speaker is still outside the cabin? The only type of system where this MIGHT work properly is band-passed. Are you building a band-passed system? If you are building a standard ported system, then you want the port and the speaker in the same air space, not separated by a firewall. What's the vehicle?
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Support the12volt.comEDIT: I see yu say it's a MR2. There is no reason to port the sub into the vehicle. It will work fine in the front boot, it'd be no different from placing the system in the trunk of a normal car. The firewall is behind the seats, not in front of it.
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Support the12volt.comIf the port is going to be outside the box.
- Don't subtract the length from the box volume, Unless you have "3 inches " inside, then you will have to subtract the volume of the port inside the box from the box volume
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TEX
Dyohn, beat me to it, I didn't think it took me that long to type that.
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TEX
yeah i wasnt too sure about putting it up front and hearing it as though it where in a typical truck..
thanx for the input though guys..
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Fiberglass Guru.
Actually as a former MR2 owner, there is a front firewall in this vehicle. On the passenger side of the car is the area that the port will have to come through the firewall. What I have seen before and seen work quite well is to build the box that you want to fit in the available space then for lack of better words, make this "port" or funnel would be more appropriate here, as large as possible, same with the hole through the front firewall.
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Top Secret, I can tell you but then my wife will kill me.
thanx forbidden..i thought the wall looked a little like firewall type material...
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Fiberglass Guru.