Little help with port length
10-07-2009, 01:31 AM
#1
Little help with port length
So I've been working out a design for a Sundown NS-12.
Anywho, I'm looking at doing 1.75ft^3 @ 36Hz.
I've worked out having that a 3"x14.5" port area I need a length of 45.82"
WTF, seriously?
I have more volume in the port than the enclosure
Do I have this right? or am I doing something wrong?
I don't usually make "smaller boxes" for single drivers.
Thanks
Anywho, I'm looking at doing 1.75ft^3 @ 36Hz.
I've worked out having that a 3"x14.5" port area I need a length of 45.82"
WTF, seriously?
I have more volume in the port than the enclosure
Do I have this right? or am I doing something wrong?
I don't usually make "smaller boxes" for single drivers.
Thanks
Last edited by stephenfleming; 10-07-2009 at 01:34 AM.
10-07-2009, 07:32 AM
#2
It's due to the LARGE port area/low tuning ratio. Having almost 25"sq of port area per 1cu ft is alot, combined with the low tuning frequency. I actually got a lil over 46" but yep, thats what your looking at.
It would decrease drastically if you went with a 14.5 x 2.25" port. Then your only looking at about 34" long for 36hz. That will still give you about 18.6" of port area per cube.
32.625"sq for 1.75cubes.
It's up to you.
It would decrease drastically if you went with a 14.5 x 2.25" port. Then your only looking at about 34" long for 36hz. That will still give you about 18.6" of port area per cube.
32.625"sq for 1.75cubes.It's up to you.
Last edited by DeadlySones; 10-07-2009 at 07:36 AM.
10-07-2009, 07:09 PM
#4
True, but your likely tuned much higher. Or have a pretty large enclosure. I don't have a problem with that much port area, actually I wish I could go bigger. Something about the feeling of air moving past you... mmmm I was just giving him an option to get what he wants just in a smaller package seeing as he was a little set back by the extra area the port was going to use. If he wanted to shorten the port length he'd have to go with a smaller port area, or a larger enclosure.
Last edited by DeadlySones; 10-07-2009 at 07:22 PM.
10-07-2009, 09:29 PM
#5
No my box is tuned at 36 hz, but it is a very large enclosure. Its just under 6 cu.ft gross. But i do agree with you, If SS went with smaller port area he could still keep his box small with not having to put so much port. What r your goals with this sub? Sound SPL both? Have you thought of using aeroports?
10-07-2009, 11:09 PM
#6
Thanks guys.
I'm looking for something that will do well with music, yet get me 140+.
I know its possible, I've done it before different sub and amp.
But I was kind of shocked with the extra length of the port.
I have thought of aeroports, but I'll need to bend it (them)
The box is going to be rather shallow, i need to conserve some space for my
little man's stuff.
I'm looking for something that will do well with music, yet get me 140+.
I know its possible, I've done it before different sub and amp.
But I was kind of shocked with the extra length of the port.
I have thought of aeroports, but I'll need to bend it (them)
The box is going to be rather shallow, i need to conserve some space for my
little man's stuff.
10-08-2009, 12:08 PM
#8
