Impedience Rise.

[Zade08]

Hope this is in the right section. If not mods please move.

I curious to know if there are any tricks to lowering impedience rise. Im refering to box mods amp mods. Pretty much any thing that will lower my impedience rise. Or is it all in how the box is built, and if so what qualities of the box make it not rise so much.

In return EYE CANDY!

[HondaMan450R]

I don't know the answer to your question....... but I damn well know she it HOT.

[kbreudi]

Woofer specs, port area, and box volume are the three ingrediants to box rise....mix them them right and you will have very little

[Zade08]

If I can get all my specs rite in winisd will it tell me impedience rise or no?

[Nightshade]

A couple things that I have found that will combat rise are spliting the load between 2 or more amps, more box volume equals less rise, and usually lower amounts of port area offer up less rise as well. Take that into consideration when you are building your box. A smaller box will be able to handle a larger amp due to the more impedence rise that it offers. A larger box is a more efficient box that will get louder on less power and will cause damage to woofers at high power if you aren't careful.

[banginAltima]

A couple things that I have found that will combat rise are spliting the load between 2 or more amps, more box volume equals less rise, and usually lower amounts of port area offer up less rise as well. Take that into consideration when you are building your box. A smaller box will be able to handle a larger amp due to the more impedence rise that it offers. A larger box is a more efficient box that will get louder on less power and will cause damage to woofers at high power if you aren't careful.

X2

[Zade08]

Im not realy worried about damaging the subs due to the fact that Im not running near the power they can take.

If IM right you have to have an amp clamp, a dmm, and do some equations to get impedience right? Or can I just get it using my dmm?

[Nightshade]

Im not realy worried about damaging the subs due to the fact that Im not running near the power they can take.

If IM right you have to have an amp clamp, a dmm, and do some equations to get impedience right? Or can I just get it using my dmm?

Correct you need an AC clamp meter and a dmm. You will need to measure the AC voltage output going to each of your subs or if they're bridged just the wires going into the amp. Once you get the AC voltage you will need to find the AC current. You do this by clamping the negative wire going to the set of speakers. I'll give you an example.

You clamp your wire and get 38.6 amps of current

You probe the + & - wires and get 61.7 volts

Next you would take the 61.7 volts and multiply the 38.6 by it to find your MAX power which would be 2381 watts

Next to find out your impedence rise you would divide the voltage 61.7 by the amperage 38.6 which would be 1.59 ohms

So if you were to have a nominal or starting resistance of .5 ohms you would have a rise of 1.09 ohms, but would have an overall reactive load of 1.59 ohms

[Zade08]

Ok cool. Thanks for the explanation makes more sence now. basicaly just use ohms law. I have a cheap centech 7 function dmm. Is there any cheap alternative to a clamp meter? Like I know you cna use an old analog amp guage of of an old tractor or hot rod and such to get your amp reading. Would this work at all?

[Boon]

IMO get some good grounding in SPL before you start worrying about things like impedance rise.

Although a big box with a small port will have less impedance rise so the amp makes more power, a small box with a huge port will be much more efficient and will probably achieve a similar SPL but with much less demand on your sub, amp and electrical system BECAUSE of the impedance rise.

Impedance rise isn't always a bad thing.