ok, i got my box built (5 cubes net @33hz), and now my subs aren't loud at all.it sounds like they're bottoming out on every song i play (i listen to mostly rap) the sq is horrible cause they bottom out non-stop, i think its the settings on my amp here they are:

subsonic=20

bass eq= 1/2 up

low pass=1/2 (out of 35-250

phase=90 deg. (what is this, and what is it for?)

level (gain)= 1/4 way up.....

is it my settings or what???i can't think of anything else unless its my box but i rechecked the math on it and it came out right....my port is 10x8, the calculator on carstereo.com i used said 21" long (20.97 btw), so i used end correction and took off 5", is this right?my port is 16" long (with no bend, just straight back, its on the side of the box btw) any help will be greatly appreciated, and im so friggin frustrated at this.... thanks in adavance

TRY TURNING DOWN THE BASS EQ-----AND PHASING IS FOR ADDED TUNING.

do you have the subs wired out of phase from one another? And what Dave said.

no, they're not out of phase....what kind of tuning does the phase knob do??so is everything fine, except for the bass eq?

Turning the phase knob will adjust the phase. But yes, turn down that bass knob, did you use a DMM or O-scope to set your gain?

no, dont have either one of them, i just set it to where it's enough bump, but to where i no its not to high to clip them......what do u mean by phase?<---what is it definition wise???

http://www.thx.com/mod/techlib/phase.html

thanks for the info, i'll go try to tweek it, brb

more:

http://www.allaboutcircuits.com/vol_2/chpt_1/5.html

http://www.geocities.com/kreskovs/TimeAligned1.html

http://www.allaboutcircuits.com/vol_6/chpt_4/10.html

When two speakers are 180 degrees out of phase, more often than not, the two signals will cancel each other out, and you will get very poor output and SQ.

Ever try turning it down ?

they were 1/2 way up (90deg), they're not out of phase i checked them, i don't know what it is....the box was 6.12 gross, with port disp. (1.12), and sub disp. (.116 total) the length was 21", with end correction it was 16, isn't all this right?it wouldn't be the shape would it???heres a pic of the box...

http://img98.echo.cx/img98/7403/seatbox7km.jpg

dont look at the specs, they were changed.....the port is on the side, right under where the amp was supposed to go and it 8.5. x 10......when u stick your ear up to the port u can hear the nasty noises from the subs......like a bottoming out, distorting noise.

Like popping ?

no, not popping and not really a scratching noise, just distorting real bad and it has horrible sq, also u can't "feel" the subs like u used to, is it because of the way they're facing the rear glass?the way i had them b4 was facing the taillights sitting on the back seats leaned up diagonal go the glass.....is my box design wrong?

try turning the bass down on the H/U.

Take ir off superbass and loud ( if there on)

i tried turning down the bass and the loud, and u hear almost no bass, when u turn it up, u get horrible sq. is the box messed up calculation wise??

From your description on the sound it fits a blown sub

Without being there it is hard to judge what the problem is.

Your hifonics amp...its a mono amp correct? (single channel)

Check your box for leaks.

Double check your wiring.

Mess with all the EQ settings, and amp settings.

does it sound better as the frequency rises?

i've never cut off the port from the original length due to end correction. i'm not saying that that is wrong, but 5" will change the tuning ALOT..and it sounds like ur subs are unloading down low...

my opinion is that when u hacked off the 5" u raised ur tuning a bunch and the teh sub/box combo doesn't wanna play low at all...

try playing tones and see if the higher tones (like 50hz and higher) sound better...especially as u go up.

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

5" is alot !

that could eaisly change tuning to way past what you wanted it to be

i know they're not blown, i had them in a sealed box last week and took them out just to install them in this box...im gonna go with leaks, and the 5" hack.....but don't i need to use end correction though?thanks again for all the help, u guys always know what to do!!!!

p.s. i believe it does get better as the frequency goes higher....(don't hold me to it though) what would this mean if this is true???

i did the math an with the same box volume, it only raised it from 33hz to 36Hz, will this be that audible??and what did it matter that my amp is mono?<---j/w btw, and when i use an online calculator and go to enter my box volume i've always entered my net vol after wood thickness is accounted for,and sub disp too of course....is this right??

5" in my little DD enclosure makes a huge difference.

i did the math an with the same box volume, it only raised it from 33hz to 36Hz, will this be that audible??and what did it matter that my amp is mono?<---j/w btw, and when i use an online calculator and go to enter my box volume i've always entered my net vol after wood thickness is accounted for,and sub disp too of course....is this right??

well, it sounds like ur not taking port volume into account. when u hacked off 5", not only did u change the tuning, but u changed box volume.

so after hacking off the 5", u changed tuning two ways.

if the sq of the enclosure does indeed improve as teh frequency's climb, then ur box is tuned high. and if it's tuned high, (more then 36hz more then likely) and ur playing low notes, ur subs will indeed be bottoming out.

also, the overall enclosure size is going to affect power handling. what size sealed boxes did u have before this ported one? if u went way larger, that's going to have some effect on how ur subs behave as well.

so, i think u have an overly high tuned box, combined with a lil less powerhandling(due to a larger box), and throw in playing stuff that's low..and u get subs that are bottoming out.

build another box without accounting for end correction, and don't forget to include port displacement in ur math. see if that helps...

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

Only way to truely tell what your box is tuned to is to read Nick's impedance rise thread. But I have a feeling you are tuned >40Hz and unloading the subs when the music is approaching 30Hz.

wow, thanks for all the info, the old bos was like around 2.6 cubes (prefab from bb). my friend has 2 he 12's in a 89 transam off a 500 watt rf (5002 i think), and u can hardly talk in the car when its hittin...he's killin me right now, i think im gonna build a box that goes down in the dip, not sure if its gonna be ported or sealed though......