MrSevs Posted June 11, 2015 Report Posted June 11, 2015 I need some help understanding port area per foot and what benefits I will gain and or lose from it. Joe X had helped me out with a design not to long ago and unfortunately I did not build a card board model to see if it would fit through the trunk opening... Due to my mistake after building it, it did not fit so I had to make some adjustments. With that being said, I lost net volume and my port area changed due to me having to narrow the port to correct tuning. My current set up is 2 SA-15's in 6.44cuft tuned to 33hz with 11.25^2 of port area per foot. Will I benefit from more port area as originally planned by Joe X? If I am calculating this correctly, it was originally 13.36^2. Any and all help is appreciated.
Kyblack76 Posted June 11, 2015 Report Posted June 11, 2015 I need some help understanding port area per foot and what benefits I will gain and or lose from it. Joe X had helped me out with a design not to long ago and unfortunately I did not build a card board model to see if it would fit through the trunk opening... Due to my mistake after building it, it did not fit so I had to make some adjustments. With that being said, I lost net volume and my port area changed due to me having to narrow the port to correct tuning. My current set up is 2 SA-15's in 6.44cuft tuned to 33hz with 11.25^2 of port area per foot. Will I benefit from more port area as originally planned by Joe X? If I am calculating this correctly, it was originally 13.36^2. Any and all help is appreciated. you lost me SMD SUPER SELLER The Burban Build Blazer Build sold Acura trunk build sold
Triticum Agricolam Posted June 11, 2015 Report Posted June 11, 2015 Port area per foot isn't the right way to look at the problem. Its an oversimplification that is just as likely to bite you in the ass as it is to help you. What you need to focus on is having enough port area for your particular application. Just how much you need depends on the size of the box, the subs, how much power you are running, and what your tuning is. Having more than you need won't hurt you any, not having enough is what causes problems. What amp are you going to be using? "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
Joe X Posted June 12, 2015 Report Posted June 12, 2015 Ok the first enclosure that wouldn't fit was 7.3 cubic feet net @34 Hz with ~97.2 square inches of port area, then you asked me to cut depth so it ended up 6 cubic feet net @34 Hz with ~97.2 square inches (same port area). Although port area per cube is a wrong concept, the changes actually increased the number rather than reducing it, went from 97.2/7.3 = 13.31 to 97.2/6 = 16.2 square inches per cube. The big difference is the net volume drop, not the port area between those two, it would be great if you posted some pics of the setup and comment on any issues you have now.
MrSevs Posted July 1, 2015 Author Report Posted July 1, 2015 Port area per foot isn't the right way to look at the problem. Its an oversimplification that is just as likely to bite you in the ass as it is to help you. What you need to focus on is having enough port area for your particular application. Just how much you need depends on the size of the box, the subs, how much power you are running, and what your tuning is. Having more than you need won't hurt you any, not having enough is what causes problems. What amp are you going to be using? I am using a Sundown SCV2000D at .5ohm.
MrSevs Posted July 1, 2015 Author Report Posted July 1, 2015 I currently built another enclosure which is 6.5cuft with a port area of 91 square inches. I got these calculations from Torres, which I recently downloaded along with Winisd. My hopes are to understand what works best in my car as I know every vehicle will produce different results. The issue it seems like I am having with this port area is it sounds like my subs are being overworked at higher volumes. Not so much like a free air but I am not getting better bass response. Can I control the sub with less port area? My worries are that I am going to overwork them. I have tried to include a picture of my current enclosure but I am currently on my computer at work and it will not let me attach anything.
Triticum Agricolam Posted July 1, 2015 Report Posted July 1, 2015 Less port area will give you less cone control, not more, and will decrease your output. Have you verified the tuning of your current box? Its easy to do if you haven't. "Nothing prevents people from knowing the truth more than the belief they already know it.""Making bass is easy, making music is the hard part."Builds:
Joe X Posted July 1, 2015 Report Posted July 1, 2015 Using your subsonic filter and lower tuning will help limit excursion IF that what you want or a problem but "better" bass response is hard to understand, may want to explain. Also post a sketch of your box to check it.
MrSevs Posted July 1, 2015 Author Report Posted July 1, 2015 Less port area will give you less cone control, not more, and will decrease your output. Have you verified the tuning of your current box? Its easy to do if you haven't. yeah... I put it together with Torres box calculator. Unless you're talking about a better way of doing so.
MrSevs Posted July 1, 2015 Author Report Posted July 1, 2015 Using your subsonic filter and lower tuning will help limit excursion IF that what you want or a problem but "better" bass response is hard to understand, may want to explain. Also post a sketch of your box to check it. I may be describing it wrong but it almost seems like a bit of distortion or the subs being overworked. I set all my gains with a DD1 so I know I am not clipping as well as my bass knob up front has a light that will turn on... or at least I hope it will alert me.
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