How amps see impedance

Home / the12volt's Install Bay / Car Audio / How amps see impedance (

Topic Closed)

Welcome Guest :)

Members

Next Page > < Prev Topic Next Topic >

Reeceddogg

Copper - Posts: 329

Joined: September 23, 2002

Location: United States

Posted: June 11, 2006 at 11:42 AM / IP Logged

I was looking a using a three sub set up on a single amp. I'm looking to acheive a 2 ohm load. Will the amp see the single impedance of each driver or the total impedance. the resistance of the subs would be 8ohm for subs one, 8 ohms for sub 2, and 4 ohms for sub 3. all the same brand and model.

Steven Kephart

Platinum - Posts: 1,737

This member has been recognized as an authority in Mobile Audio and Video. Click here for more info.

This member consistently provides reliable information

Joined: November 06, 2003

Location: Oregon, United States

Posted: June 11, 2006 at 11:54 AM / IP Logged

How can they be the same model but be a different impedance? Usually a manufacturer will change the model number slightly to indicate the impedance difference. The amplifier will see the total impedance of the circuit. However the power distribution willl not be consistent if the impedances are in fact different. Of the total power the amplifier produces, more power will go to the lower impedance sub than each of the other two subs. This willl most likely cause it to play louder.

Search for other posts by Steven Kephart

Reeceddogg

Copper - Posts: 329

Joined: September 23, 2002

Location: United States

Posted: June 11, 2006 at 12:11 PM / IP Logged

Not same model but series. I want to put 3 kicker L5 on a brutus bxi 1606. i was looking at 2 dual 2 ohm subs wired in series, and a dual 4 also wired in parallel. Is there anyway around the unequal power distribution? also how can i calculate how much each sub would be getting. and i was mistaken it should be a 1 ohm load.

Steven Kephart

Platinum - Posts: 1,737

Joined: November 06, 2003

Location: Oregon, United States

Posted: June 11, 2006 at 12:18 PM / IP Logged

Power will only distribute evenly if the resitances are identical. So you would need 3 subs of the same impedance. Just keep in mind that you don't HAVE to achieve the lowest impedance the amplifier can safely handle. Going with a 4 ohm load instead of a 2 ohm load for instance is only about a 3 dB difference in output.

Reeceddogg

Copper - Posts: 329

Joined: September 23, 2002

Location: United States

Posted: June 11, 2006 at 12:21 PM / IP Logged

do you know of any 3 sub set that i can use. I already have this amp.

forbidden

Platinum - Posts: 5,352

This member has made a donation to the12volt.com. Click here for more info.

Joined: November 01, 2003

Location: Alberta, Canada

Posted: June 11, 2006 at 12:26 PM / IP Logged

This is about as close as you are going to get with a 3 sub setup.So either dual 4 ohm subs wired in a series / parallel circuit or 3 8 ohm subs wired in a parallel circuit.

Option 1 (parallel) = 2.67 ohm load

Speakers wired in parallel

Recommended Amplifier: Stable at 2 or 1 ohm mono

Top Secret, I can tell you but then my wife will kill me.

Reeceddogg

Copper - Posts: 329

Joined: September 23, 2002

Location: United States

Posted: June 11, 2006 at 12:38 PM / IP Logged

that's supposed to be a 1 ohm load. What if i did 3 dual 2 in series/parallel. thats 1.3 ohms. what calculation would i use to figure out how many watts the amp is capable of at this impedance.

DYohn

Moderator - Posts: 10,741

This member has been recognized as an authority in Electrical Theory. Click here for more info.

Joined: April 22, 2003

Location: Arizona, United States

Posted: June 11, 2006 at 1:07 PM / IP Logged

Reeceddogg wrote:

that's supposed to be a 1 ohm load. What if i did 3 dual 2 in series/parallel. thats 1.3 ohms. what calculation would i use to figure out how many watts the amp is capable of at this impedance.

What is "supposed to be a 1 ohm load"? Your amp? No, an amplifier's rating is for the minimum load it can safely handle, not a requirement of some sort. If you are referring to the graphic forbidden posted, it is correct.

Support the12volt.com

forbidden

Platinum - Posts: 5,352

Joined: November 01, 2003

Location: Alberta, Canada

Posted: June 11, 2006 at 1:39 PM / IP Logged

Using 3 dual 2 ohm subs can yeild a number of different loads on a amp. Look in the blue sidebar to the left of the screen for woofer wiring, that is where you will find the woofer calculator. In the case of your dual 2 ohm subs, the cloest you are going to get is this load, which may well be beyond the capabilities of the amp that you have chosen for the task (if it is only stable to 2 ohm mono for example). Here is this diagram as found in the left column.

Option 1 (series/parallel) = 1.34 ohm load

Voice coils wired in series, speakers wired in parallel

Recommended Amplifier: Stable at 1 ohm mono

Top Secret, I can tell you but then my wife will kill me.

Ravendarat

Platinum - Posts: 2,806

Joined: February 23, 2004

Location: Canada

Posted: June 11, 2006 at 1:44 PM / IP Logged

Here is another question, what amp is this? Is it 1 ohm MONO stable or one ohm STEREO stable. Big difference here.

double-secret reverse-osmosis speaker-cone-induced high-level interference distortion, Its a killer

Next Page >

Printable version

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Search the12volt.com

Follow the12volt.com

Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.