Hey all,
I've designed an enclosure that implements a slot port, referencing JLAudio's box-building guides and related, and knowledge garnished from this web-site and many others. My question is , does it matter what side of a box a port is on, and how the slot port is oriented (vertical or horizontal)? I was wondering because right now my box would have a port firing toward the rear of my trunk, the same direction that my subs would be firing. I was thinking that it would be pretty cool it I put the port on the "back" side of my box (the side opposite of the side with my subwoofers), and flipped the "slot" so the long side would be horizontal instead of vertical. This way, if I cut a hole in my backseat (where my center armrest flips down) more bass would infiltrate my car's interior. Can you relocate port(s) anywhere that you see fit, as long as they're an acceptable distance from walls and such? And do ports have to vent on the same side as your speakers to work properly?
Replies (4)
ttocs on 05/10/2004 21:42:02
there might be a nominal difference with the cabin gain but it will not make a huge difference. I have seen them point almost everywhere and not noticed.
BigJMan on 05/10/2004 21:47:03
Thanks for replying ttocs,
That's exactly the opposite of what I expected to hear, but maybe you're right.
What's your opinion Swez, others?
uochronos on 05/10/2004 22:47:56
i would also think the gain wopuld be minimal. i also dont think what side the port is on would matter. i usualy port it out the back myself. but in smaller areas it helps to have it point the same direction so there is more air in front of it,.
swez on 05/12/2004 11:09:13
Port location in general is pretty much up to the designer and application. The location of the port does not matter much, as long as the port(s) are not too close to hard surfaces that would impeded air flow.
Your idea of porting into the main cabin is a common option and it will provide more bass energy into the interior cabin in the method you noted. The main issue when porting to the rear, is the bass waves coming off the rear of the cone, will be ~180 degrees out of phase with the bass energy coming out of the sub cones.
Noting that, your ports will have to be well isolated from the truck bass waves to limit phase cancellation issues at certain frequencies. Basically, an air tight fit is best here. You'll have to channel bass energy out of the ports, to the interior cabin. Also, as you get closer to port tuning frequency (fo) more bass will be coming from the port output than the front cones. This means the deep lows will come from the ports while upper bass will be trapped in the trunk. Other than that, this can be done with favorable results.
Swez
I've designed an enclosure that implements a slot port, referencing JLAudio's box-building guides and related, and knowledge garnished from this web-site and many others. My question is , does it matter what side of a box a port is on, and how the slot port is oriented (vertical or horizontal)? I was wondering because right now my box would have a port firing toward the rear of my trunk, the same direction that my subs would be firing. I was thinking that it would be pretty cool it I put the port on the "back" side of my box (the side opposite of the side with my subwoofers), and flipped the "slot" so the long side would be horizontal instead of vertical. This way, if I cut a hole in my backseat (where my center armrest flips down) more bass would infiltrate my car's interior. Can you relocate port(s) anywhere that you see fit, as long as they're an acceptable distance from walls and such? And do ports have to vent on the same side as your speakers to work properly?
Replies (4)
ttocs on 05/10/2004 21:42:02
there might be a nominal difference with the cabin gain but it will not make a huge difference. I have seen them point almost everywhere and not noticed.
BigJMan on 05/10/2004 21:47:03
Thanks for replying ttocs,
That's exactly the opposite of what I expected to hear, but maybe you're right.
What's your opinion Swez, others?
uochronos on 05/10/2004 22:47:56
i would also think the gain wopuld be minimal. i also dont think what side the port is on would matter. i usualy port it out the back myself. but in smaller areas it helps to have it point the same direction so there is more air in front of it,.
swez on 05/12/2004 11:09:13
Port location in general is pretty much up to the designer and application. The location of the port does not matter much, as long as the port(s) are not too close to hard surfaces that would impeded air flow.
Your idea of porting into the main cabin is a common option and it will provide more bass energy into the interior cabin in the method you noted. The main issue when porting to the rear, is the bass waves coming off the rear of the cone, will be ~180 degrees out of phase with the bass energy coming out of the sub cones.
Noting that, your ports will have to be well isolated from the truck bass waves to limit phase cancellation issues at certain frequencies. Basically, an air tight fit is best here. You'll have to channel bass energy out of the ports, to the interior cabin. Also, as you get closer to port tuning frequency (fo) more bass will be coming from the port output than the front cones. This means the deep lows will come from the ports while upper bass will be trapped in the trunk. Other than that, this can be done with favorable results.
Swez
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