Can someone thoroughly explain impedance rise?

[themommyvan 10+ year member]

Most boxes I have tested hace around a 3 ohm rise. So from 1 ohm to around 4. The only way to really tell is to clamp it.

 

[OoMesKoO 10+ year member]

Sounds good.

Heres a question... Say the amplifier isnt stated 1 ohm stable, rated 2 ohms, and you run it at 1 ohm. There should, in theory... be no problems because it will in fact NOT be running a "nominal" 1 ohm load. Correct?

 

[bad @SS chevy 10+ year member]

have*

 

[Tehgregzor 10+ year member]

Wow. that has to be the best way anyone has ever explained something on this website, I have ever seen. I really REALLY appreciate your response!

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x2

 

[Flipx99 5,000+ posts]

have*

great poast!

 

[themommyvan 10+ year member]

Some amps wont even turn on under the rated ohm load. All depends on the protection circuts.

If you notice you cant find imp rise on music only on tones. Have you ever had a sub hooked up to a DMM and pushed on it? Sometimes it will read -100 ohms.

Imp rise is mainly for burps not for music. I cant really answer your question cause all amps are different.

 

[gladiator_jai 10+ year member]

Since Impeadance rise is also affected by music.

Running it at less than stated stable resistance and playing music, there might be certain periods in which the amp might see a very low impeadance rise and hence less that rated resistance. That might be harmful and throw it into protect, am I thinking correctly??

 

[themommyvan 10+ year member]

Since Impeadance rise is also affected by music. Running it at less than stated stable resistance and playing music, there might be certain periods in which the amp might see a very low impeadance rise and hence less that rated resistance. That might be harmful and throw it into protect, am I thinking correctly??

Can not figure imp rise on music only tones. Your amp will see imp change when the subs move.

 

[gladiator_jai 10+ year member]

Can not figure imp rise on music only tones. Your amp will see imp change when the subs move.

I was trying to answer his question on running a 2 ohm stable amp on 1 ohm as it will never see 1 ohm due to impeadance rise.

My answer is based on what you said before, i.e. impeadance rise is not constant, hence there may be instances where the amp will see a 1 ohm impeadance or any thing lower than it is rated as stable.

 

[themommyvan 10+ year member]

I was trying to answer his question on running a 2 ohm stable amp on 1 ohm as it will never see 1 ohm due to impeadance rise.
My answer is based on what you said before, i.e. impeadance rise is not constant, hence there may be instances where the amp will see a 1 ohm impeadance or any thing lower than it is rated as stable.

Sorry I read it as a question. But yes but for a very short time.

 

[Immacomputer 10+ year member]

Wow. that has to be the best way anyone has ever explained something on this website, I have ever seen. I really REALLY appreciate your response!

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Take it with a grain of salt as it really isn't very accurate.

The impedance rise is due to a resonance point of the system. That resonance point is changed by the enclosure and its environment. It is frequency dependent which means that the impedance changes when different frequencies are played. The range of frequencies affected by the impedance rise is usually pretty small and it does not have a large effect on the sound of the driver as the driver won't need as much driving force (power) because it is at or approaching a point of resonance.

The higher order system, the more points of resonance. The order number comes from the poles in DE used for the transfer function.

High impedance is not always a bad thing. When a ported enclosure is resonating (around the tuning frequency), the speaker will see a high impedance from the enclosure. That causes the cone to not move much but the port is excited and producing the majority of the output.

The best way to reduce impedance rise is by using a properly designed transmission line enclosure. They are not always loud even though they have a flat impedance. So more power does not always mean more output.