hey how do you calculate your port lengths?

hey how do you calculate your port lengths?

I've been using this: http://www.bitpusher.in/?p=ported

ohh, but if my port is 5 inches wide, wouldnt it need to be five inches all around? cuz if i did a 36 inch length there would only be 3inches of space at the end

Edited October 7, 201212 yr by NickHall

ohh, but if my port is 5 inches wide, wouldnt it need to be five inches all around? cuz if i did a 36 inch length there would only be 3inches of space at the end

Your port should have the same amount of area from the entrance to the exit.

Anything apart from the port is enclosure volume.

ohhh so the port starts at the very beggining of the port opening in the box? ive been under the impression that if the port goes close to the back wall then the distance should be the same as the width of the port and should turn

ohhh so the port starts at the very beggining of the port opening in the box? ive been under the impression that if the port goes close to the back wall then the distance should be the same as the width of the port and should turn

It only bends if you run out of room going that direction.

Am I missing something Stefan?

He's doing a side port. The external width of the box is 40.5" - 0.75" - 0.75" = 39"

The port length would be 36". Why wouldn't 36" fit in 39"?

So if his port was 38" long he would still not have to bend it?

so it should effectively look like this?

Am I missing something Stefan?

He's doing a side port. The external width of the box is 40.5" - 0.75" - 0.75" = 39"

The port length would be 36". Why wouldn't 36" fit in 39"?

So if his port was 38" long he would still not have to bend it?

If it was 38" long then that's pretty close to the panel, and I would reconsider it, but he would have 3.75" left open to the port entrance. You don't think that's enough?

If so, he could make the one length 34.75", and 1.25" for the second part. Correct?

so it should effectively look like this?

That's what I was envisioning, but wait until Rick replies to my last post. I'm curious, and he's built more boxes then me.

aight, either way is cool as long as ill have enough volume in the end

Am I missing something Stefan?

He's doing a side port. The external width of the box is 40.5" - 0.75" - 0.75" = 39"

The port length would be 36". Why wouldn't 36" fit in 39"?

So if his port was 38" long he would still not have to bend it?

but he would have 3.75" left open to the port entrance. You don't think that's enough?

I always try to bend at the port width if possible. 3.75 should be enough but I would still bend at 34.75. I know with aero ports people say half of the port width, but that is a minimum and I always try to use more if possible. Would your way sound any different than my way, maybe not. It is just how I have always done things and I was curious as to see when you would draw the line and bend it.

Am I missing something Stefan?

He's doing a side port. The external width of the box is 40.5" - 0.75" - 0.75" = 39"

The port length would be 36". Why wouldn't 36" fit in 39"?

So if his port was 38" long he would still not have to bend it?

but he would have 3.75" left open to the port entrance. You don't think that's enough?

I always try to bend at the port width if possible. 3.75 should be enough but I would still bend at 34.75. I know with aero ports people say half of the port width, but that is a minimum and I always try to use more if possible. Would your way sound any different than my way, probably not. It is just how I have always done things and I was curious as to see when you would draw the line and bend it.

so would you say go through the trouble of bending it or jus leave it with 3.75 inches of clearance?

Am I missing something Stefan?

He's doing a side port. The external width of the box is 40.5" - 0.75" - 0.75" = 39"

The port length would be 36". Why wouldn't 36" fit in 39"?

So if his port was 38" long he would still not have to bend it?

but he would have 3.75" left open to the port entrance. You don't think that's enough?

I always try to bend at the port width if possible. 3.75 should be enough but I would still bend at 34.75. I know with aero ports people say half of the port width, but that is a minimum and I always try to use more if possible. Would your way sound any different than my way, probably not. It is just how I have always done things and I was curious as to see when you would draw the line and bend it.

so would you say go through the trouble of bending it or jus leave it with 3.75 inches of clearance?

It doesn't require much more effort, so mine as well play it safe, and bend it.

so would you say go through the trouble of bending it or jus leave it with 3.75 inches of clearance?

I personally would, but in the end it is your call.

so would you say go through the trouble of bending it or jus leave it with 3.75 inches of clearance?

I personally would, but in the end it is your call.

how much would it bring the box volume down to?

what would it tune the box to to just bring the port to 34.75 inches? that would give me five inches all the way through

Edited October 7, 201212 yr by NickHall

how much would it bring the box volume down to?

what would it tune the box to to just bring the port to 34.75 inches? that would give me five inches all the way through

34.75 vs. 36 would most likely be an undetectable audible difference.

would there be a spl loss or gain going either way?

would there be a spl loss or gain going either way?

34.75 vs. 36 would most likely be an undetectable audible difference.

On a meter it might make a minute difference.

aight so it would be like this correct?

but what would the volume end up as?

Edited October 7, 201212 yr by NickHall

nvrmnd its like 4.053ft^3 tuned at about 33.285htz. unless my math is jus really screwed up

Edited October 7, 201212 yr by NickHall

Thanks to everyone who has put input on this, i really and truely appreciated the help. i will be posting a build log for this box later, look out for it if you want. will also include installing door speakers extra batts and amps and stuff

ok so i used sketchup to design the enclosure you mentioned to the best of what i could tell you were saying.

Did i do it right? is it tuned correctly? whats it tuned at?

Oh and i think i kinda went overbaord on screenshots, lol

http://www.soundsolu...&attach_id=3097

I'd use this one before all the others. 4.4ft^3 @ ~33hz add a little bit of dowel bracing and it would be perfect.

ok so i used sketchup to design the enclosure you mentioned to the best of what i could tell you were saying.

Did i do it right? is it tuned correctly? whats it tuned at?

Oh and i think i kinda went overbaord on screenshots, lol

http://www.soundsolu...&attach_id=3097

I'd use this one before all the others. 4.4ft^3 @ ~33hz add a little bit of dowel bracing and it would be perfect.

the other one is about 4.5 cubes too, but i accounted for sub displacement (.34ft^3 for two 12's) and dowel bracing displacement. so it'll be roughly 4-4.1 ft^3 in the end.