ported? inverted? what am i thinking?

if so, i'm on my way to a pair of xxx's...

built it today, will have pics up tomorrow...

its only 5.5" high, and goes all the way across the back of the trunk in front of my amp rack...

all i need to do tomorrow is install the port and tune it, and its ready to pound... i need to pick up some carpet, too...

infinity website reccomends 35hz for port tuning, so im gonna stick with that...

i think its gonna be too loud for me, as it was already too loud in a .6 cu ft sealed inclosure all the way in the back of the car...
a 1 ct ft ported box is going to blow me away... i was just bored today, thats the only reason i did id... that and ive never built a ported box, so i wanted to learn what it was all about...

stay tuned for updates tomorrow...

can you please explain to me how you "tune" a box?

Maybe by altering the amount of air space inside the box until the desired frequency reproduction is attained. Just a thought, because I had to do that with my setup...back in the "good 'ol days."

Ported boxes are tuned to a particular frequency by varying combinations of box size and port length.

Well, I was 1/2 right.

Originally posted by 03blackout if so, i'm on my way to a pair of xxx's...

I thought you were getting a new sub for a second...RE..."XXX" hehe

Yep, ported is the way to go. I have twin ported boxes in my car and they hit as loud as I want them to, even though I am currently looking for an even nastier setup.

anyway, i finshed and installed my new 1 cu ft. ported box today, and although it is LOUD as hell, it is definitely a lot muddier...

im going to try and play with the port length and stuff and see where that gets me...

overall, i like it, because it looks really nice, and is a whole lot louder (sounds like 2 or 3 10's rather than 1), but the clarity is the drawback...

anyone know how to tune a ported box?

should i make the port longer or shorter?

what's it tuned to now?

Check out WinISD to find out if you don't know already. If I remember right, a longer port makes it lower, and a bigger port makes it higher.

holy self-contradiction, batman...

according to winisd, a longer port tunes it lower...

It took me forever to get my old setup right. Now my new setup is less complicated and sounds even better. (less bass, but better sound quality IMO)

Originally posted by 03blackout
holy self-contradiction, batman...

according to winisd, a longer port tunes it lower...

that's what I was saying, a longer port tunes it lower, and a larger port (larger crossectional area, keeping the same length) tunes it higher

First off you need to calculate the amount of air flow of you port... take the area of the port circumfrance multiplied by length and try to match as closely as the specs for the sub call in ported encloser. Usually a shorter port produces higher frequencys and louder volumes, a longer port produces lower frequencys and less volume (easy way to think about it)

Also if you inverted your sub remember to kick it out of phase or your ported box with sound really funny.... ( that means wire it positive to negative, and negative to positive)

Also try using a square port because you get less port noise, and cleaner sounding bass!

http://www.the12volt.com/caraudio/boxcalcs.asp#por

Originally posted by 03blackout
anyway, i finshed and installed my new 1 cu ft. ported box today, and although it is LOUD as hell, it is definitely a lot muddier...

im going to try and play with the port length and stuff and see where that gets me...

overall, i like it, because it looks really nice, and is a whole lot louder (sounds like 2 or 3 10's rather than 1), but the clarity is the drawback...

anyone know how to tune a ported box?

should i make the port longer or shorter?

i know how to tune a ported box, i need some specs of your box and the thickness of wood used as well as the space consumed by your sub, my mtx uses .06cu/ft so thats what i would guess but if you can tell me otherwise that would be alright, also what kind of music do you listen too?

1 cu ft box
¾" mdf
inverted sub

emo/new age rock/80s rock/rap

one more question, what size is your current port

2" diameter...

theres an elbow, and like a 8" length of port...

You have a tuning freq of 29.5Hz, which should fit that sub pretty well. With a port that small though you have a vent mach of .28 which is pretty bad. If it's at all possible, you could increase the port to 3", make it 19" long (to keep the same tuning freq), and that would drop the vent mach to .12 which is much more reasonable.

Basically a high vent mach means the air is rushing out very fast, and you can hear it. If it's bad enough the sound can even overpower the sub itself.

don't tell him to go with 26hz, that is stupidly low for a 10" sub, he should go with around 30hz. My box is tuned to 42hz right now and i listen to basically the same music he does and it sounds great.



i'll just keep my ramblin stupidity up there so he can make me look like a jackass after he justed corrected himself.

I can't imagine how music sounds when you cut off everything below 42hz. I mean, songs with mostly low bass like Late Night Tip... turned to songs that have no bass... the travesty. Its like listening to my sealed box... low bass cut off at the knees... horrible.

yeah I forgot to change the box size in WinISD when I put that post up, but I fixed it and edited. If WinISD's database is correct, that sub has an Fs of 28Hz, so tuning the box anywhere in the high 20's is not absurd at all. Now 42Hz for a daily driver box is rediculous, that would sound terrible on music. I sure hope you have a subsonic filter set to around 38Hz if you want your sub to last any decent amount of time. By tuning that high you're also cutting off nearly half of the bass spectrum, I can't believe how much you must be missing from music.

i got the specs for your port in your box, it works out to be a 3" port of 20.3" in length for a 30hz tuning frequency, also try tapering the entrance and exit of the port to cut down on wind noise.

infinity's website says a 3" diam. port of length 10.4" would be perfect, tuned to 35hz...

you guys are just regergitating numbers that winisd gave you... i got the same numbers you did...

i would assume that infinity tested different box sizes with different ports to try and find the best one to match the woofer, before they proclaimed it the "best" setup... the only reason i didnt do that in the first place is because i couldnt find any 3" pvc pipe...

im going to do that tomorrow... 3" x 10.4"... if that doesnt help, then we can experiment further...

i don't use winisd, also does winisd take into account the size of the box?

where are the pics?? :D

I don't think 35Hz would be the best choice for a SQ setup, seriously. If you want SQ (which I assume you do based on your comments), you really need to tune lower, 30 at the max.

Originally posted by 2001 SE #2
I don't think 35Hz would be the best choice for a SQ setup, seriously. If you want SQ (which I assume you do based on your comments), you really need to tune lower, 30 at the max.

ok, that i'll try... thanks...