multiple subs, power division
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=16856
Printed Date: May 28, 2024 at 10:56 PM
Topic: multiple subs, power division
Posted By: donkason
Subject: multiple subs, power division
Date Posted: July 29, 2003 at 9:41 PM
If you wire 4 dual 4 ohm v.c.'s in series and then run all 4 subs parallel you get a 2 ohm load to your amp. If you amp is supposed to put out 1200 watts at 2 ohms each speaker should get 1200 watts, correct. This has become a point of controversy in some other post and I want to get it cleared up by a professional.
Replies:
Posted By: nedgeworth
Date Posted: July 29, 2003 at 9:50 PM
Effectively each voice coil will receive 150watts. So each sub will be grab 300watts from that amp. What are models of sub and amp are you looking at running?
Posted By: donkason
Date Posted: July 29, 2003 at 9:54 PM
It is for another person on the 12 volt. He is looking to run 4 kicker L7's and a kicker 1200.1 amp. I thought the power was distributed evenly, 1200 watts each sub because each sub was at 2 ohms. Maybe I am wrong. I still need some more opinions before I change my mind.
Posted By: wvsquirrel
Date Posted: July 29, 2003 at 10:02 PM
The 1200 watt rating is the total amount of wattage that is produced for the channel under a 2ohm load at the terminal (where the speakers connect to the amp). It doesn't matter if you have 1, 2, 3, 4, etc... speakers hooked up. As long as you have a 2ohm total load at the amp, then 1200 watts total is produced. That 1200 watts gets distributed evenly (for all intensive purposes) among any subs connected to that channel.
In your example, each of the 4 subs would receive 300 watts since the total final ohm load at the amp is 2ohms. Since each of the subs is a DVC, then each voice coil would receive 150 watts (effectivly still 300 watts per sub). ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: nedgeworth
Date Posted: July 29, 2003 at 10:02 PM
You divide by the number of drivers. And running DVC is effectively 2 subs in 1 in a sense. So you divide the 1200 by 8. If it was only one sub then it would be getting 1200 total to it. But 600 per coil.
Posted By: nedgeworth
Date Posted: July 29, 2003 at 10:05 PM
Thanks squirrel. You have a bit better way with words than me at the moment. Probably cause i'm trying to work and do this at the same time 
Posted By: bberman1
Date Posted: July 29, 2003 at 10:06 PM
The power will be divided by the number of drivers. So each sub will not be getting 1200 watts. Each sub will get 300 watts.
Posted By: Special-K
Date Posted: July 29, 2003 at 11:27 PM
Yeah like the rest said, each sub will recieve about 300 watts each. Nice choice of subs and amp btw.
Posted By: wvsquirrel
Date Posted: July 29, 2003 at 11:39 PM
Which model L7's are you referring to? The 10, 12, or 15 ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: Special-K
Date Posted: July 29, 2003 at 11:46 PM
BTW you will want to run more than that to those subs. Like 500+ each. Under powering is bad.
Posted By: wvsquirrel
Date Posted: July 29, 2003 at 11:56 PM
The minimum RMS output (per sub) needed from an amp would be more like:
600 watts per sub for the 10" version
750 watts per sub for the 12" version
1000 watts per sub for the 15" version ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: bberman1
Date Posted: July 30, 2003 at 12:16 AM
One more thing to add which I left out in my earlier post. If you have a 2 ohm load on that Kicker 1200.1 which you are referring to you would only get 600 watts ,and if you divide that by 4 you get 150 watts per sub. So like my buddy WVSQUIRREL said above a 15" L7 should have around 1000 watts per driver.
Posted By: wvsquirrel
Date Posted: July 30, 2003 at 12:24 AM
Great catch bberman! I completely missed double checking the amps output specs at 2ohms and just concentrated on the sub specs  ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: Special-K
Date Posted: July 30, 2003 at 12:25 AM
Yeah. You will want a couple of those amps
Posted By: tdsteele
Date Posted: July 30, 2003 at 12:28 AM
Just for everyones info this post is in regards to the ones on here titled l7 15's in a silverado. https://www.the12volt.com/installbay/forum_posts.asp?tid=16791&tpn=2
Posted By: wvsquirrel
Date Posted: July 30, 2003 at 12:37 AM
I hope you haven't already bought the equipment cause bberman1's post really shoots down the power with 4 L7 4ohm DVC subs and 1 KX1200.1 amp.
With 4ohm DVC's, you can wire 2 of them in parallel for a 1ohm load. Still, each sub would only be receiving 600 watts per driver, and you would need a second KX1200.1 for the other 2 subs. Even then though, you would still be seriously underpowering the subs.
If you wanted to keep the 4 L7's (and assuming you have the S15L72's), then you would be better off getting:
1) 4 amps rated 1000 x 1 @ 2ohms
2) 2 amps rated 2000 x 1 @ 1ohm
With that much power you will also need to seriously beef up your current electrical system with at least a HO alternator ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: wvsquirrel
Date Posted: July 30, 2003 at 12:47 AM
Sorry, the amp recomendations above were for S15L74's (4ohm version), not the S15l72's (2ohm version)
If you were to exchange the (4) 4ohm L7's for (2) 2ohm L7's and another KX1200.1 amp, then you could run each 2ohm L7 in parallel to its own amp at a 1ohm load for 1200 watts per sub. You may even save some money as well, but don't forget about a HO alternator too.
IMO, running 2 S15L72's and 2 KX1200.1's would give you increased SQ and SPL vs. running 4 S15L74's and 1 KX1200.1 ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: l7sdime
Date Posted: July 30, 2003 at 8:57 AM
this is doubleduece's bro again. ok so if i am goin to put 4l7 12's in my s-10 i shopuld plan on buying the dual 2 ohm version and 2 kx1200.1's right?and then wire the subs in a series and the amps parallel? i thnk im startin to understand all this stuff i just want to get the most wattage out of my amp and the most bass out of my subs because lookin at it now im plannin on spendin mucho dinero just for the system not even for the install or batteries or alarm that i am getting. i thank everybody for the help that they have gicen me and my bro. wes
Posted By: wvsquirrel
Date Posted: July 30, 2003 at 9:36 PM
No. I was saying with (2) 15" 2ohm L7's and (2) KX1200.1's you could wire each sub to its own amp (1 L7 per KX1200.1) at a 1ohm load for 1200 watts per sub.
And remember, most of this thread was based around the 15" model L7 (1000RMS 2000Peak) not the 12" model L7 (750RMS 1500Peak)
Since you're looking at the 12's instead of 15's, you want around 750 watts per sub (instead of the 1000 watts that the 15 requires). If you're die-hard on using 4 12" L7's, then you would want (4) 4ohm L7's and (2) KX1200.1's. Wire two L7's per KX1200.1 at a 1ohm total load per amp (two 4ohm DVC's wired in parallel will produce a 1ohm total load) and you should receive around 1200 watts total, or apx 600 watts per sub. That's still 150 watts shy of what you should be using, but it's as close as you're gonna get with that equipment.
Something else to keep in mind. The KX1200.1 ratings of 1200 x 1 @ 1ohm is not based on a 12 volt electrical system. I believe Kicker bases on a 14.4 volt electrical system. So you'll be running at an even lower RMS than 600 watts per sub with a 12 volt electrical system.
One other thing is a stock alternator will not keep up with 2 KX1200.1's, it probably couldn't even keep up with 1. Just because you're getting another battery, you will also need a High Output alternator to keep your electrical and charging systems functioning properly, and to produce enough power to allow the KX1200.1's to function to their fullest potential. Look at around another $400 - $600 for a quality HO alternator. ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
Posted By: wvsquirrel
Date Posted: July 30, 2003 at 9:39 PM
Sorry, couldn't edit my last post. The last paragraph should read...
One other thing is a stock alternator will not keep up with 2 KX1200.1's, it probably couldn't even keep up with 1. Even though you're getting another battery, you will also need a High Output alternator to keep your electrical and charging systems functioning properly, and to produce enough power to allow the KX1200.1's to function to their fullest potential. Look at around another $400 - $600 for a quality HO alternator ------------- Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
|