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IgnoreMe
09-22-2007, 07:20 PM
i have read a nice thread over at SSA about impedance rise. impedance rise is basically accepted as you just build and test and accept what you get.

my question is, has are there any proven tips that can help minimize impedance rise? i have heard the idea behind a TL enclosure lies in the fact that it will help keep impedance stable if designed correctly. but how about regular ported boxes?

smaller the box = greater the rise? vice versa?

lower the tuning = lower the rise? vice versa?

things like that make me wonder if there is a way that we can at least TRY to design around keeping impedance down. im assuming its basically impossible, which is why i haven't seen but maybe 1 thread on the subject that went into detail.

themommyvan
09-22-2007, 07:26 PM
Not much info is set in stone about it. The best info I came up with is to keep it at a minimum is to make if as efficent as possible.

IgnoreMe
09-22-2007, 07:30 PM
http://www.soundsolutionsaudio.com/forum/index.php?showtopic=2690&hl=impedance

this is the thread im talking about. it ended too quickly IMO :)

but its a good read and i would always love more info from experienced people.

edit: especially checkout jellyfish420's posts. he has a couple different boxes and graphs the rise against each other. impedance rise changes vastly each time.

heres one for the people that dont want to take a look

http://img227.echo.cx/img227/7238/impedancegraph3rk.jpg


and another. the tuning of course is going to make a difference where the biggest and smallest rise is, but for example look how jumpy the 23hz tuning is compared to the others

http://img165.echo.cx/img165/2826/image0020da.gif

jellyfish420
09-22-2007, 08:20 PM
man...that was a while ago. the main reason i was doing those is to find out exactly my tuning. impedance is lowest at tuning.

IgnoreMe
09-22-2007, 08:25 PM
man...that was a while ago. the main reason i was doing those is to find out exactly my tuning. impedance is lowest at tuning.

yes impedance is lowest at tuning. however there are other factors that change, and effect impedance throughout a band of frequencies. trying to see if there are way to try to control that.

i see some guys that have huge rises. say up to 8 ohms. and then build another box and the rise will come down to say, 4 ohms. that would be a doubling of power at that freq, which to me would be time wells spent rebuilding the box.

jellyfish420
09-22-2007, 08:28 PM
yes impedance is lowest at tuning. however there are other factors that change, and effect impedance throughout a band of frequencies. trying to see if there are way to try to control that.

i see some guys that have huge rises. say up to 8 ohms. and then build another box and the rise will come down to say, 4 ohms. that would be a doubling of power at that freq, which to me would be time wells spent rebuilding the box.

here's how i found the lowest rise...

build and test
build and test
build and test
build and test
build and test
build and test

every woofer will react diff, to every box, in every different vehicle.

IgnoreMe
09-22-2007, 08:33 PM
here's how i found the lowest rise...

build and test
build and test
build and test
build and test
build and test
build and test

every woofer will react diff, to every box, in every different vehicle.

you have found 0 patterns in all the testing you have done?

dleccord
09-22-2007, 08:33 PM
im pretty sure the smaller the box, the lesser the impedance rise and vice versa.

jellyfish420
09-22-2007, 08:35 PM
the only pattern i found was...that i was doing alot of testing.

IgnoreMe
09-22-2007, 08:36 PM
the only pattern i found was...that i was doing alot of testing.

lol

Wkbdkid
09-22-2007, 08:38 PM
im pretty sure the smaller the box, the lesser the impedance rise and vice versa.
I would think its depend on the sub. Rise is also caused by heat, an you would think smaller the box is less air for the sub? **** idk.lol

IgnoreMe
09-22-2007, 08:39 PM
im pretty sure the smaller the box, the lesser the impedance rise and vice versa.

kinda ******.

if you think about it...your building for efficiency yet the bigger you make your box trying to gain efficiency, the higher your rise is lowering your power anyways lol.

thats what it seemed they were catching onto in the thread on ssa.

jellyfish420
09-22-2007, 09:15 PM
kinda ******.

if you think about it...your building for efficiency yet the bigger you make your box trying to gain efficiency, the higher your rise is lowering your power anyways lol.

thats what it seemed they were catching onto in the thread on ssa.

guess your gonna have to go sealed ;)

IgnoreMe
09-22-2007, 10:57 PM
guess your gonna have to go sealed ;)

ive tried sealed before...its not for me :)

IgnoreMe
09-23-2007, 03:07 PM
anyone else?

05gliguy
09-23-2007, 03:16 PM
Are you trying to get info because your setup has bad imp. rise? (George)

tommyk90
09-23-2007, 03:20 PM
There's really no set in stone ways to lower your impedence rise.

As stated before, all you can do is try different enclosure/port combinations to see what works best.

Are you trying to get more SPL out of your setup or something? Because if so, then impedence rise may not be your main concern. I've seen some enclosure that had less rise in my truck, but were quieter. :)

IgnoreMe
09-23-2007, 03:20 PM
actually i have no setup as of right now. however i love to learn. and this has been a question ive wanted to know for a while but i dont know any competitors that might have done any testing to get an idea of any techniques that could help.

its just something that interests me, for the most part. i also would like to test using boxes that hold some value behind them, versus just building random boxes and hoping they will work.

edit: tommyk: nope not really, like i said, its just a quetion ive been pondering, but it seems your answer on having no rules set in stone, is basically what im being told by many other respected members.

photocrazy8
09-23-2007, 03:22 PM
from my reading and talking to (something taxi - i forget the rest of his name) there is NO way to figure help stop rise, its going to be diff in every situation...

IgnoreMe
09-23-2007, 03:30 PM
from my reading and talking to (something taxi - i forget the rest of his name) there is NO way to figure help stop rise, its going to be diff in every situation...

well this topic ***** then lol. hoping it would turn into something informative.

probably will have more reliable answers trying to figure out the meaning of life

photocrazy8
09-23-2007, 03:32 PM
well this topic ***** then lol. hoping it would turn into something informative.

probably will have more reliable answers trying to figure out the meaning of life

pretty much :)

DBfan187
09-23-2007, 03:33 PM
use a sealed box

IgnoreMe
09-23-2007, 03:34 PM
use a sealed boxhey come on you big pink running ****...i already said i dont want a sealed box. ill take my chances on teh portEdz

DBfan187
09-23-2007, 03:37 PM
Then you're stuck. :)

IgnoreMe
09-23-2007, 03:39 PM
Then you're stuck. :)

at staring at your pink **** :santa: lol...that avatar will probably be known as one of the greats on this site for a long time.

DBfan187
09-23-2007, 03:43 PM
http://www.come2africa.com/images/smiley.gif

IgnoreMe
09-23-2007, 03:45 PM
you know me too well...