View Full Version : question about ports
ok i know everyone knows this but what ever. if a slotted port was smaller does the freq go up? or does the freq go down?? thanks
Terry Jackson
11-03-2008, 10:20 PM
tuning is based more on how long the port is.
but i would say the frequency will go down if you make the opening smaller
352DIMEon20s
11-03-2008, 10:33 PM
how about the other factors? is the box staying the same dimensions? same length port? if you decrease the size of the port, your in turn increasing the net volume of the box (port will be taking up less space inside the box).. some extra factors to take into consideration.
what dimensions are you working with? and what freq.? maybe i can help
CBFryman
11-04-2008, 08:02 AM
how about the other factors? is the box staying the same dimensions? same length port? if you decrease the size of the port, your in turn increasing the net volume of the box (port will be taking up less space inside the box).. some extra factors to take into consideration.
what dimensions are you working with? and what freq.? maybe i can help
Calculus!
:banghead3:
its for 4 12's and its 2 chambers, the port is 15inches long and each chamber is about 5 cubes
352DIMEon20s
11-04-2008, 11:42 AM
its for 4 12's and its 2 chambers, the port is 15inches long and each chamber is about 5 cubes
ok, for each 5 cube box (gross size), a port with an opening 4" x 15" and length of 15" would give you about a 36hz tuning. the box will be about 4.3 cubes net after port displacement. should slam pretty good
thats basicaly where it is now, but its a wall and my peak note is 46 Hz but with my jeep sealed with the windows up i only do a 142ish wtf idk what i should do, i think if i tune it up it will get louder, i was just woundering how i can tune it up without taking the wall out
352DIMEon20s
11-04-2008, 04:41 PM
thats basicaly where it is now, but its a wall and my peak note is 46 Hz but with my jeep sealed with the windows up i only do a 142ish wtf idk what i should do, i think if i tune it up it will get louder, i was just woundering how i can tune it up without taking the wall out
seems like the problem lies within the wall, tuning it to 46hz wont make you happy for daily, but that should bump you up 1 or 2db just by raising the tuning. You want to make sure you seal off the wall completely to the sides/roof/bottom of your jeep, giving you less air to compress. Inter-changeable ports will give you the best of both worlds (competing vs. daily). like ~34hz for daily, ~46hz for competing
how much power are you running? that should be a priority to give the subs more power too. are you burping it at ~46hz?
also, if you do tune it up higher like your sayin, it might be "louder on the mic". but to the ears, 30-40hz usually seems "louder/moves more air" (with windows down mostly). theres too many frickin variables and options lol, all i can say is try messing around with your wall, see what gets the loudest in your vehicle. once you figure that out, then work on more subs/more power.
yeah the wall is not 100% sealed off yet... ha and im only running 2 cheep 1200 watt amps to my ma audio 12's which are 300rms
droppedisuzu
11-05-2008, 10:16 AM
Mark
Did you try standing up your old box I did 4 u?
You know that box pulled some decent #'s, maybe you can make it seal right!
yeah i was thinking about that,hmmmmm i might give that a try, i have till the 15th to do somthing different so ill try that hopefully
352DIMEon20s
11-05-2008, 03:18 PM
yeah i was thinking about that,hmmmmm i might give that a try, i have till the 15th to do somthing different so ill try that hopefully
you going to the show in wildwood?
you going to the show in wildwood?
yes i am going i might be alittle late, i get out of work at 5 and its a 2+ hour drive for me so yeah, i want to put my old box in and make that a wall but i dont know if i will have enough time... im going to need 6 solid hours to make it work but im too busy i dont know if i will have time to do that
PEDRO MODEAN
11-05-2008, 04:55 PM
you could seal it with spray foam, but tape some plastic to the roof and sides so it doesnt ruin your interior.
i would think that would work.
you could seal it with spray foam, but tape some plastic to the roof and sides so it doesnt ruin your interior.
i would think that would work.
thats a great idea ill try that, i already am getting the other box ready to go back in for like the 10th time, im going to stand my old box up, the ports will be on top, i doubt that it will play music well because it will be tuned higher and stuff. im aiming for the show on the 15th, my girlfriend and i will be working on it in the morning
tonight is when im taking the old out and putting the old back in ha, then tomrrow im putting the subs in and sealing alll around the sides with foam then it might be loud.
long420
11-08-2008, 05:29 PM
IF you are hitting 142 with bottom of the line ma audio subs and sony amps you should already be proud of the box you have!
IF you are hitting 142 with bottom of the line ma audio subs and sony amps you should already be proud of the box you have!
i was in stock 2 in daytona and did a 148.9 so then i built a wall and only did a 142... i already put somthing new in today, trim panels tomrrow and then meter maby and put some good numbers on
ok everything is in!!! and sealed and foamed all around. it is realy realy loud at 55Hz so i cant wait to see what it does on the meter
long420
11-10-2008, 01:37 PM
what series ma subs do you have?
what series ma subs do you have?
they are the cheep ma audio 120 xe
Klownicle
11-11-2008, 08:25 AM
ok everything is in!!! and sealed and foamed all around. it is realy realy loud at 55Hz so i cant wait to see what it does on the meter
55 is high to be tuned for base race'n in the 139.9.
55 is high to be tuned for base race'n in the 139.9.
who said anything about the 139.9 class??? if their are not many people in the 149.9 class i will try for that... and i have a special song that i found :grin:
vBulletin® v3.8.7, Copyright ©2000-2012, vBulletin Solutions, Inc.