4 or 2 ohms on a 4channel?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=61405
Printed Date: April 28, 2024 at 3:02 AM

Topic: 4 or 2 ohms on a 4channel?

Posted By: shott8283
Subject: 4 or 2 ohms on a 4channel?
Date Posted: August 16, 2005 at 12:05 AM

Im confused about something.... i understand the basic idea of ohms and 4 or 2 ohm load on a sub amp.... but how do you factor in 4 or 2 ohm load for a 4 channel highs and mids amp? how would the wiring be different? and what does it mean when a 4 channel amp has the option of 4 or 2 ohm option? thanks

Replies:

Posted By: stevdart
Date Posted: August 16, 2005 at 5:13 AM

This might help to clarify it:

4-channel amplifier = four "mono" amplifiers.
Any amplifier can be used for subwoofers as well as other speakers.
The load is the impedance of the speaker(s) attached to the amplifier.
An amplifier has a limit to the amount of current it will produce. "Stable at 2 ohms" means that a load lower than 2 ohms will cause the amplifier to produce current greater than its capacity to handle it successfully.
A lower impedance load results in lower voltage / higher current from the amplifier. A higher load results in higher voltage / lower current. See the minimum load limitations in the amp's specs.

(An amplifier is specific in its specs about the lowest impedance load it can handle, but it will always be able to handle a load with higher impedance. Some amps will spec out numbers for 4 ohms, some will go as high as 8 ohms in the specs.)
Wiring a sub to a 4 channel amp: most commonly bridged across two of the channels. When an amplifer is stable at 2 ohms, it means 2 ohms per channel. Bridging is combining two channels, so when you do that you have to be sure the load is 4 ohms or higher because the load will be split between the two channels. A 4 ohm load bridged is equivalent to 2 ohms/channel.
Where you would put a 2 ohm load onto a mono sub amp, you would put a 4 ohm load bridged onto a two-channel amp. The output of each amp would be at 2 ohms.
Meet Mr. Ohm's Law:
........where power is the product of voltage times current, and the impedance of the load will determine the ratio.
A great study is chapters 2 - 12 of https://www.bcae1.com/

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: shott8283
Date Posted: August 16, 2005 at 7:07 PM

WOW.... that is an awesome explination.... thank you very much!!!!!!!!

Posted By: Izzum88
Date Posted: August 17, 2005 at 7:14 PM

wait wait wait, i thought i got it but now i dont, i have a 3 channel amp and i have 2 of the channels running in parrlel with one of the channels that is in series, now the all of the channels are running in series with another 4 channel amp in which two of the channels or ran in series with each other and then each of those is in parallel with each other. What are my options.

Posted By: jeffchilcott
Date Posted: August 17, 2005 at 7:38 PM

WHAT??!!?? how many speakers do you have..how many amps. What are the model's and brands or subs and amps.

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2009 0-1000 Trunk WR 154.0DB 2009 1001+ Trunk WR
2007 USACI World Champion
2007 World Record
2006 USACI Finals 2nd Place

Posted By: chrisAWD
Date Posted: August 17, 2005 at 9:47 PM

<quote>WHAT??!!??</quote> haha...coudn't have said it better

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car 1 = alpine 9807, mtx 404+mtx 311d, polk speakers, kappa 10"
car 2 = pioneer 7700, kicker 400x1, kicker 60x4, 10"compvr x2, kappa speakers

Posted By: Izzum88
Date Posted: August 18, 2005 at 4:01 AM

i have 2 amps 8 speakers, 4 off the 3 channel and 4 off the 4 channel. I have 2 speakers running off one channel on the 3 channel amp, nevermind though i figured it out

Posted By: Izzum88
Date Posted: August 18, 2005 at 6:17 PM

SO, any help ?

Posted By: stevdart
Date Posted: August 18, 2005 at 9:42 PM

Uh, how 'bout Dr. Kevorkian?

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: oxygen65
Date Posted: August 19, 2005 at 12:55 AM

dude its simple like dat main, all you gotsta do is hook up 7 more subs and then the ohm law will come into effect and dats how yall get the big spl stuff goin on, dude i had the same problem, i figured it out thought and now my system is hittin 183 db's. now thats a system

Posted By: Izzum88
Date Posted: August 19, 2005 at 2:18 AM

shhh dog i put like 19 W7s wait not even W7s those new W8s man they be pumpin i hit 339.5 the other day the meter was in side the sub tho so i dunno how that did

Posted By: speedwayaudio1
Date Posted: August 19, 2005 at 4:22 AM

Izzum88 boy your profile say's your only 10 years old, but you act like your only 5. Grow up and find some where else to play. posted_image

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Big Dave