Paper Calculations

[RichardXTC]

hi... i was just wondering if paper calculations like working out your port lenght frequency etc... is accurate or would it be better to test trial and error?

[scratchy]

I prefer doing my calculations on my own

[AP Zoutes]

if your math is good they are accurate for the enclosure

[scratchy]

Thats the catch....if your math is good 

[RichardXTC]

WELL my maths is pretty good so i can do it. oh and how do you work out the cubic feet of a box? to you convert to inches then height X width X depth then divide by 1728(or something)

[AP Zoutes]

exactly.....A good book for the formulas I've used is "Great Sound stereo Speaker Manual" by David Weems it covers almost everything. I think it's good for everyone to read and start their understanding with. The only thing is the ports used in the book are small but you can adjust for that.

[RichardXTC]

HMMM ok i wont be able to get that book but i have found a few sites with some nice calculations. so you say the way i said to work cubic feet is correct?

[AP Zoutes]

yes, it's correct. HxWxD / 1728 minus sub,port and bracing displacement..Also make sure they are inside dimensions. Start with the outside demension and subtract for material. So if you have a width of 20" and are using 3/4" mdf subtract each wall width which = 18.5

[RichardXTC]

OH ok thanks alot man!!! are you good at designing boxes? cause im busy building a wall and just need someone to check over the port...

[AP Zoutes]

I can help....but going to bed...Leave your dimensions, sub info, tuning you want etc....I will look it over in the morning