lilrezy50 Posted May 16, 2020 Report Share Posted May 16, 2020 Good evening everyone, I am looking for a quick math check on a box design and confirm my center slot port length Overall enclosure dimensions: W - 30.25" H - 14.25" D - 25 Material - .75" Woofer displacement .28 2 common port walls Port W - 4" Port H - 12.75" Port Length 19" Does that port length of 19" look correct to come out with a tuning freq around 34.97, 51.00In2 Port area, 4.99 ft3 gross and 4.19ft3 net? Link to comment Share on other sites More sharing options...
shredder2 Posted May 16, 2020 Report Share Posted May 16, 2020 Checking those dimensions in Torres quick and dirty...no bracing and single baffled Link to comment Share on other sites More sharing options...
Joshdashef Posted May 16, 2020 Report Share Posted May 16, 2020 What power are you running ? SMD Tool Map (2022): https://www.stevemeadedesigns.com/board/topic/220267-smd-tool-map-2022/ My Port Size Calculator (in progress): https://www.stevemeadedesigns.com/board/topic/217087-port-size-calculator-in-progress/ Common Port Walls for a Slot Port: https://www.stevemeadedesigns.com/board/topic/217076-common-port-walls-why-it-matters-to-your-box/?tab=comments#comment-3240313 Link to comment Share on other sites More sharing options...
1point21gigawatts Posted May 16, 2020 Report Share Posted May 16, 2020 And on sundown subwoofers I would run the enclosure and port area 10-20% larger than recommended depending on the amp. The weaker the amp, the weaker the enclosure the smaller the increase and vise versa. If you’re running them subwoofers at rated or close to the I would make the enclosure 20% larger than recommended, volume and port area for better sound. And I would tune it a little bit lower to compensate for the increase. And if you’re running around double rated, like most people do, then I would run the enclosure around 10-15% larger in volume and port area and tune it a little lower than recommended. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
lilrezy50 Posted May 16, 2020 Author Report Share Posted May 16, 2020 Thank you guys, I’m running a KX 1600.1 @ 2 Link to comment Share on other sites More sharing options...
Joshdashef Posted May 17, 2020 Report Share Posted May 17, 2020 4 hours ago, lilrezy50 said: Thank you guys, I’m running a KX 1600.1 @ 2 Seems to be within minimum port area requirements to avoid loss of output due to velocity but it could be bigger if you have the room to fit a larger port. 60-70” would be closer to ideal SMD Tool Map (2022): https://www.stevemeadedesigns.com/board/topic/220267-smd-tool-map-2022/ My Port Size Calculator (in progress): https://www.stevemeadedesigns.com/board/topic/217087-port-size-calculator-in-progress/ Common Port Walls for a Slot Port: https://www.stevemeadedesigns.com/board/topic/217076-common-port-walls-why-it-matters-to-your-box/?tab=comments#comment-3240313 Link to comment Share on other sites More sharing options...
1point21gigawatts Posted May 17, 2020 Report Share Posted May 17, 2020 2 hours ago, Joshdashef said: Seems to be within minimum port area requirements to avoid loss of output due to velocity but it could be bigger if you have the room to fit a larger port. 60-70” would be closer to ideal Agreed. 60” would be ideal. That’s a 15% increase. 70” is 34% bigger than recommended. That might be a little too much of an increase. Under the right circumstances and remaining figures he could make that work. But like you said 60” would be super ideal. That 15% percentage of increase is my go to and what I design most of my enclosures to. But with 60sq” of port area he would need to increase the net volume of his enclosure the same percentage and then lower the frequency to about 33hz. But if he changes the port area to 60” and extends the length of the port to lower the tuning it would bring his original enclosures net volume down about 5% and since it was already 19% larger than recommended he would be right on the money and ready to go. He could leave it at 35hz and be fine but since the enclosure has been altered from recommendations for better output then the frequency has to be changed as well for better output to meet the new expectations the subwoofer would want to achieve the new higher output capabilities. “How can we help you?” “And don’t forget to tell them that the customer isn’t always right.” Link to comment Share on other sites More sharing options...
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