Confirm port requirements

joeybutts

pair of rss390hf in 6 cubes tuned to 24hz on 560w.....  to keep air speed under 30 I'm getting a need for 60sq in of port area.  So either six 3.5" ports 40" long or a 3.2" x 19" slot port 40" long.  Can I go less area?  I can do the slot port, just curious how I can tell not necessary....

jr@mac

In a vehicle, you can filter port noise if you take advantage of placement. Plus, that's fucking loud modeling. If that is your preferred listening level, you will soon not hear chuffing anyways. Re-model at 100db and see how that changes the ol' chuff factor.

joeybutts

woah.  The power level is so low for 100db, makes it obvious why two 4" ports is general consensus, and port velocity is barely going.  

Thanks JR.

ani_101

if there is that much headroom, would sealed and boosted work?

joeybutts

I was going to go sealed but the advantage from 27-45 ported is too nice..... and I don't have much headroom power wise....

SPL wise is another matter.....😈😈😈😈

jr@mac

Now, model with cabin gain. I think WinISD has an approximation for that. Longest distance in cab of vehicle kind of thing. I'm guessing you will still hit 110+ DB below 80hz with minimal input. 

joeybutts

So..... found a quick cabin gain simulation method.... this is going to be insane!  Sim says 135db @29hz.  Perfect.