Sundown SA12 Ported Box

[Joe X]

misprint

2.5^2*3.145*2

39.31.

right below the 10in^2 per cube.

http://cholla.mmto.org/speakers/theory/vented-2.pdf

keep going.

why ya think SPL guys use HUGE ports?

Bear in mind that some of those setups are tuned as high as 60Hz, Sv increases with frequency as you can see in the link provided.

[Triticum Agricolam]

...

why ya think SPL guys use HUGE ports?

To keep port velocity down so as not to lose a bunch of output to port compression. Which was pretty much the point of all the port testing I've been doing.

[bassfreak85]

you try them in any vehicles? i'm interested to see. In a few weeks ill do some testing with a prototype myself.

while i saw a little diffidence in the FR you had plotted it wasn't enough to say nay BUT you have a ripple above tuning and a slight ripple below tuning but you still only around 1/4 the SD where is alot of setups use 1/2 to 1.25 the SD. the woofer i tested i noticed a difference between 25in^2 and 70. peaked harder at tuning and fell off faster..

http://cholla.mmto.org/speakers/theory/vented-2.pdf

did some more reading on this article and it doesn't really suggest to much port area but more so an Ideal. which was what i was looking for.

I've experienced loosing output with too much port area. these where in car measurement though, it could have been other factors involved..

so far though I'm inclined o say i am wrong and may have over looked other variables.

like i sad ill be doing some testing on a pretty large high output driver and my goal is the find the best possible alignment.

[Triticum Agricolam]

I did not do any testing with that box in a vehicle. I don't see where there would be much difference though.

I'm curious to see what your results are when you do your own testing.

Do you have any examples of a ported box where the port is 1.25x the Sd? Or even equal to Sd?

[bassfreak85]

I did not do any testing with that box in a vehicle. I don't see where there would be much difference though.

I'm curious to see what your results are when you do your own testing.

Do you have any examples of a ported box where the port is 1.25x the Sd? Or even equal to Sd?

you compete? i've seen and built several.

just search youtube. and remember the CMS and MMS affects the outcome as well..

[Triticum Agricolam]

I do not compete. I'd rather spend my money on tools. I build boxes for people that do compete though.

So how much port area did that box in the video have? I couldn't tell.