box tuning

[phemps 10+ year member]

if it was 3.75 net it would need to be 16.95

per cube?? or total port area? where are you coming up with these port area numbers?

 

[wenn_du_weinst 10+ year member]

it's done to what steve from rd said

even though sic can't talk with out being disrespectful. I will tell you exactly what I did

I took the specs steve said to do ( I have never used any rd subs and never plan to )

then found out what the port length should be with a chamber of 2.6ft tuned to 35hz came out to 27" for me. then I built the box around the port to get to the 2.6' I needed the chamber to be

 

[wenn_du_weinst 10+ year member]

oh and just to clarify

2.6 is not a random number it's the chamber where the sub is in not including the port

3.75 is total area including port

 

[gtbike900 10+ year member]

imo i would run one 4 inch aero 5.56 inches long giving him 3.25 cubes appox after dis tuned at 35 but i like low port area

 

[SicAudio 5,000+ posts]

ha nope. gotta get your port length from your net volume, then calculate its displacement then use that to give you your third box dimensions to account for the port displacement

exactly u use net volume to calculate for the length the 3rd final volume is vb that the sub actually has available.

every sub maker on the planet that i know of uses this formula ( robert smalls ) to do tuning.

hell even the online calculators use it and verify my tuning is correct. you can not account for an unknown volume ( port volume ) u have to have a port to know its volume to deduct from the gross to get the vb lolz.

 

[gtbike900 10+ year member]

per cube?? or total port area? where are you coming up with these port area numbers?

16.95 was the length for the current design if it was really 3.75 cubes net

 

[phemps 10+ year member]

length

yea thats what i said it would be close to before i never did the exact calculation. but the problem was he was going by the volume before his port displacement. he needs to 16. 96 or whatever you said with a net volume of 3.75. box needs to be reworked

 

[SicAudio 5,000+ posts]

gt was saying 16.95 length not area

volume is not gross minus port it is gross minus bracing sub ect..

useable vb is minus everything

 

[phemps 10+ year member]

exactly u use net volume to calculate for the length the 3rd final volume is vb that the sub actually has available.
every sub maker on the planet that i know of uses this formula ( robert smalls ) to do tuning.

hell even the online calculators use it and verify my tuning is correct. you can not account for an unknown volume ( port volume ) u have to have a port to know its volume to deduct from the gross to get the vb lolz.

trooofff. your need more boxx recalculate your box by taking the port and finding its displacement then add that to the sub displacement, and bracing displacement, and your net volume, and you have your gross. thats how you get your last box number i usually figure out my depth last

 

[gtbike900 10+ year member]

i like little boxes with little port keeps box rise down and gives cone control and smaller port play lows better

 

[phemps 10+ year member]

i like little boxes with little port keeps box rise down and gives cone control and smaller port play lows better

depends what your going for really...

 

[gtbike900 10+ year member]

i have 2 6 inch aeros in my box that is 10.8 gross 9.5 net thats like 57 inch of port and it tuned to 27 my ports are 1 inch longer than stock lenght

 

[gtbike900 10+ year member]

26.75 hrts tuning to be exact

 

[gtbike900 10+ year member]

and i do 152.8 at 37 on 3600 clamped watts and like 151 and change at 30

 

[SicAudio 5,000+ posts]

so vote then wenn is the guy that says i am wrong lol

no matter how u figure it or call gross vb or net minus sub or net or whatever a 3.75cf gross box is roughly 16-17" of port length at 12.5 x 3" to tune at 35hz. period lolz