Sundown Sa18 Box Design

[Joe X]

Very few people will need 25Hz but if you don't increase power a lot it's safe to try either.

[jfoodstamp]

So when I'm looking at the graphs you plotted is that the anticipated frequency response difference as opposed to overall out over a sealed box?

[Joe X]

The plot has nothing to do with a sealed box, basically is the projected in-car response of the ported box you were asking about in your OP.

[jfoodstamp]

Ok thanks for your help. Pics to come probably right after Christmas

[jfoodstamp]

Joe...... What do you think of this? 11 cubes net 197 square inches of port and tuned to 33 hz.... Would you mind plotting the frequency response of that one vs. the other 33hz tuned box you came up with

[Joe X]

Since you are using two drivers and doubling airspace you will get the same theoretical response, you gave a little more port area than I recommended but that is no problem, if anything it may help, only downside, your box get somewhat larger. Specs wise I think you are good, your box layout, vehicle and the setup will determine your final results, let us know how it went!

[Joe Kralovetz]

On 12/8/2015 at 11:24 PM, Joe X said:

Since you are running moderate power you will get better output with 5.5 net and about 80 square inches per driver will be fine, no problem if you do more other than the larger box, here's the modeled response for that sub 5.5 net @36Hz 600W per driver :

Joe X, how could I apply this to my previous post you commented on earlier for 2 sa 18s? While I figured 200in2 for port area you here mention 80in2 per driver? if I was to lower my port area how much of a difference would the 80in2 per be to 100in2? I could manage a box size for 2 sa 18s in 38X30X26 giving me 9.95ft3 net with a port of 36.5w 4.5H 32L giving me roughly 164.25in2 port area would that work on 1k rms per driver?