tat2jerry Posted January 7, 2019 Report Share Posted January 7, 2019 enclosure 7.5 ft. net. 2 sundown SA15's Orion XTR 2500.1 will I have enough port area with 4 6" big ass ports (Areo ports) I'm looking for a mix of SQ and SPL ? Or would I get louder with a 120 square inch slot port I like the looks of the big ass ports Link to comment Share on other sites More sharing options...
DiBo Posted January 7, 2019 Report Share Posted January 7, 2019 2 hours ago, tat2jerry said: enclosure 7.5 ft. net. 2 sundown SA15's Orion XTR 2500.1 will I have enough port area with 4 6" big ass ports (Areo ports) I'm looking for a mix of SQ and SPL ? Or would I get louder with a 120 square inch slot port I like the looks of the big ass ports 120 is too much port for sa-15's. You'll need around 96in². I'd make the enclosure 7ft³ personally. Just my opinion and experience with sa-15's Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 7, 2019 Report Share Posted January 7, 2019 1 hour ago, DiBo said: 120 is too much port for sa-15's. You'll need around 96in². I'd make the enclosure 7ft³ personally. Just my opinion and experience with sa-15's No such thing as too much port area as long as you can fit the ports is the space you have. 4 hours ago, tat2jerry said: enclosure 7.5 ft. net. 2 sundown SA15's Orion XTR 2500.1 will I have enough port area with 4 6" big ass ports (Areo ports) I'm looking for a mix of SQ and SPL ? Or would I get louder with a 120 square inch slot port I like the looks of the big ass ports It would help to know what your tuning frequency is, but assuming its somewhere around 32 hz four 6" ports is plenty of port area for the power you are running. When using more than two aero ports, they begin to be less efficient compared to just one or two larger ports, however you have enough port area its not going to be a big deal. As far as compared to a 120 sq in slot port, again you have enough port area it shouldn't make much difference. Do whatever you think will make you happier, either is a good choice. I will caution you to be careful with excursion due to the size of your box and the power you will be running. You will want to have your subsonic filter properly set. "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: Link to comment Share on other sites More sharing options...
DiBo Posted January 7, 2019 Report Share Posted January 7, 2019 6 minutes ago, Triticum Agricolam said: No such thing as too much port area as long as you can fit the ports is the space you have. I'd have to disagree with this. You can absolutely have too much port area. I've done it. Subs sounded like garbage. There's a sweet spot to every woofer and enclosure imo and experience with the 30+ enclosures I've made last year. I'm not as experienced as you but I do design and build my own boxes pretty well. Jmo Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 7, 2019 Report Share Posted January 7, 2019 59 minutes ago, DiBo said: I'd have to disagree with this. You can absolutely have too much port area. I've done it. Subs sounded like garbage. There's a sweet spot to every woofer and enclosure imo and experience with the 30+ enclosures I've made last year. I'm not as experienced as you but I do design and build my own boxes pretty well. Jmo We may just have to agree to disagree on this, and that's OK, this community is about sharing different experiences. I've done quite a bit of my own testing and whenever something bad happens its always something other than port area that's causing the problem. Ports certainly can be too long and that can give pipe resonance issues with the port, or if the port layout isn't good you can get unloading issues, but I've never had a problem from just having a lot of port area. "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: Link to comment Share on other sites More sharing options...
mothra Posted January 7, 2019 Report Share Posted January 7, 2019 with 4 6" ports in a 7.5 cube enclosure, I'd love to know how that's going to get tuning in the 30s? also for the "too much port area", that is just a fact. you can easily have too much port area. you get to a point that the subs just act as free air, it can also get extremely peaky b/c the tuning is so high. if nothing changes, nothing changes You don't know what you don't know, till you don't know Link to comment Share on other sites More sharing options...
Triticum Agricolam Posted January 7, 2019 Report Share Posted January 7, 2019 12 minutes ago, mothra said: with 4 6" ports in a 7.5 cube enclosure, I'd love to know how that's going to get tuning in the 30s? also for the "too much port area", that is just a fact. you can easily have too much port area. you get to a point that the subs just act as free air, it can also get extremely peaky b/c the tuning is so high. I agree with you that tuning is going to be difficult, those ports are going to have to 30+" long, but it is still possible. I also agree that if you tune too high the output is likely to be peaky. If you make a port absolutely unreasonable big, yes it will cease to function as a ported box, but that point is MUCH more port area than most people would think and you almost always run into other problems (like too long of a port) before you get to that point. The OP isn't anywhere near that point with four 6" aeroports. So please tell me, at what point do YOU consider it to be too much port area? Please be specific. "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: Link to comment Share on other sites More sharing options...
mothra Posted January 7, 2019 Report Share Posted January 7, 2019 21 minutes ago, Triticum Agricolam said: I agree with you that tuning is going to be difficult, those ports are going to have to 30+" long, but it is still possible. I also agree that if you tune too high the output is likely to be peaky. If you make a port absolutely unreasonable big, yes it will cease to function as a ported box, but that point is MUCH more port area than most people would think and you almost always run into other problems (like too long of a port) before you get to that point. The OP isn't anywhere near that point with four 6" aeroports. So please tell me, at what point do YOU consider it to be too much port area? Please be specific. I have a couple simple rules, port shouldn't be longer than 20" and velocity shouldn't be lower than 20m/s. port area shouldn't be a target when designing an enclosure. keeping port length under 20" will prevent having port resonance and port wall flexing. having a velocity of 20m/s minimum allows to tune lower and still keep a really responsive system. if nothing changes, nothing changes You don't know what you don't know, till you don't know Link to comment Share on other sites More sharing options...
shredder2 Posted January 7, 2019 Report Share Posted January 7, 2019 44 minutes ago, Triticum Agricolam said: but that point is MUCH more port area than most people would think The top statement is something I totally agree with, that's 108in2 of port below on a single Sa-15 and it does really well as designed for the goals I had in mind when starting out. I think every enclosure should be modeled and every factor taken into consideration when designing as an enclosure is just a collection of compromises with a goal in mind anyways. This question was posed on another forum and 130in2 of port was discussed with a 35hz tune. It got me thinking, I dusted off something I had planned for my Blazer and prettied it up. The collection of compromises I came up with in my application for that power level was this... I don't subscribe to those "general rules" that obviate the need for modeling and people subscribe to so just a calculator can be used. Every enclosure is a collection of compromises and should have all factors taken into account My .02 Link to comment Share on other sites More sharing options...
DiBo Posted January 7, 2019 Report Share Posted January 7, 2019 1 hour ago, mothra said: I have a couple simple rules, port shouldn't be longer than 20" Really? Not disagreeing... My new enclosure has a 29" port planned... And most of the slot port enclosures I've built, the port gets pretty long to get proper tuning. To tell you the truth, every single enclosure I've built with a tuning of around 32-35hz have been over 20" long. I need to learn how to model. I'm building an enclosure as we speak for for Sundown X12 V2 subs. 19.75x48x36 subs up, port back .80 woofer displacement Triple .75" top baffle 3.375x46x29 port 1.5" thick ( all 4 subs will load off of this port wall) 1"brb on the sides, bottom, front and back Third baffle will recess the subs so 1.5" of meat to screw to with #10 1.5" spax screws. Material is cut! I should've ran it by triticum or Joe Link to comment Share on other sites More sharing options...
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