SP4v2 15 Port area Per foot Experience?

[Cardboardcat15]

As the title suggests, anyone here have experience with SP4v2 15's? Currently building for 3 of them in a 4th order, but wanted to to ask around to see if anyone who's built for/run them before has suggestions on what the drivers like. 

 

Messaged Fi and was told ~55^2in was optimal (10.34^2 per foot according to torres) , but that seems really low to me. Then again, I'm no master builder and they are the manufacturer. 

 

What do you guys think?

[Joshdashef]

8 minutes ago, Cardboardcat15 said:

As the title suggests, anyone here have experience with SP4v2 15's? Currently building for 3 of them in a 4th order, but wanted to to ask around to see if anyone who's built for/run them before has suggestions on what the drivers like. 

 

Messaged Fi and was told ~55^2in was optimal (10.34^2 per foot according to torres) , but that seems really low to me. Then again, I'm no master builder and they are the manufacturer. 

 

What do you guys think?

Working on just a simple 4th bass reflex, not a bandpass, for the v2+ 15 going into a trunk. Been bouncing around a lot between port area and came to the conclusion that if you want maximum output use triticums port area calc. However, if you use it realize that you may lose some bandwidth for the sake of pure output. How much, well that would seem to be install specific 

 

For my own sanity I think I will make my box with an interchangeable port to allow me to fine tune with my cabin gain and test various degrees of port area. 

 

 

Here is the link to the google sheets:

https://docs.google.com/spreadsheets/d/1mwBK02mF-8BF3mxqqB8WG0H0GUbTmgQfpJODlo_0moQ/edit?pli=1#gid=1632976665

 

And the thread about it:

 

[1point21gigawatts]

On a 4th order enclosure, the port area has to be 1/2 of the total cone area. 3 15s is 529.87” of cone area, so the port area has to be as close to 264.935sq” as you can get it and tune it to 45hz because you want to peak at 45hz for optimal output. Sp4s do really well in a 4th order enclosure. I’ve used triticum’s port area calculator and it is severely flawed. I use to look up to that dude on know how of enclosure builds until I used his calculator and could yield a frequency below 49hz on a basic bass reflex enclosure when using the port area he suggested and the width of the port had to be a certain width based on the rms fed to not cause port noise. That calculator calculates such big port area it makes it impossible on a good number of applications to tune that application, no matter the port length. When it comes to numbers and calculations, once I see flaw, I veer away. 

[Cardboardcat15]

Thanks guys, I figured I'd just start at 260^2in of port and shrink from there if need be. 

[CstrokerV]

Make your port interchangeable... only way to really see what’s going to do well In Your vehicle and that 55 was probably per woofer 

[kalilac619]

13 hours ago, Cardboardcat15 said:

Thanks guys, I figured I'd just start at 260^2in of port and shrink from there if need be. 

Definitely make it interchangeable.... I’ve changed the front port about 7 times to get it where it’s at...current port is 221^2in which is the loudest on the meter but my other port that is 300^2in is doesn’t meter as well but demos better 

[Cardboardcat15]

On 5/28/2020 at 8:44 AM, kalilac619 said:

Definitely make it interchangeable.... I’ve changed the front port about 7 times to get it where it’s at...current port is 221^2in which is the loudest on the meter but my other port that is 300^2in is doesn’t meter as well but demos better 

Yeah thats what I ended up doing. I probably should've made the opening bigger towards 300sqin so I could play with bigger ports, but i Figured 260 is a safe spot. 

[1point21gigawatts]

12 hours ago, Cardboardcat15 said:

Yeah thats what I ended up doing. I probably should've made the opening bigger towards 300sqin so I could play with bigger ports, but i Figured 260 is a safe spot. 

It’ll be fine