Another port question

[Alex JB 10+ year member]

I've uses some formulas from the internet and I'm coming up with a 26" long 3.3" dia (changing it to a slot 5 x 1.7 for same area) port for 30hx tuning on a 0.97 cu ft box for an RE08.

OK, now for the stupid questions,

1. Does this seem long?

2. Do I need to remove the approx port volume from the total box volume and do the calc again? I think this will tell me it need to be even longer! //content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

3. the Hz value in each calc is at 30 for now, what happens if they are not the same?

this is the sketch of the box and my initial calcs.

Click to read more...

 

[Alex JB 10+ year member]

I tried to use the winap program, downloaded it to my laptop at hiome but it didn't have RE subs and it wouldn't let me put the parameters in, kept saying the Q values were wrong so I went the old skool hand calc route.

I notices the -1.463R was cut off the end of the Lv calculation in my pic too, it is in the figures to come up with the 26" lg port though.

Any suggestions on the frequency?

 

[Alex JB 10+ year member]

OK, the JL 8W0 looks ok in the calc too.

I think I can fit either but still not sure if the internal volume in the cal is before or after port volume and driver displacement. ?