3 subs
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=52220
Printed Date: May 03, 2024 at 5:56 PM
Topic: 3 subs
Posted By: wrathchild281
Subject: 3 subs
Date Posted: March 20, 2005 at 10:43 AM
hey you guys i just got a 3rd 8in L7 4ohm. So now i have 3 4ohm dvc subs. How could i wire that to like a kicker kx1200.1 or a jbl1200.1? I was hoping i could wire it down to 1ohm but im not sure if thats possible. Also im a little worried about overheating, would you guys say that the kicker amp would run alot cooler then the jbl? thanks.
Replies:
Posted By: stevdart
Date Posted: March 20, 2005 at 11:10 AM
https://www.the12volt.com/caraudio/boxcalcs.asp This is a handy calculator for figuring impedance total on any combination of subs. Three SVC 4-ohm subs would connect in parallel to 1.33 ohms. Okay to use with a mono amp rated to 1 ohm.
Posted By: wrathchild281
Date Posted: March 20, 2005 at 11:19 AM
ok thanks but hey but my subs are dvc subs. So how would that work out?
Posted By: stevdart
Date Posted: March 20, 2005 at 11:44 AM
Figure that you have to wire each sub to either 2 ohm parallel or 8 ohm series. Then just plug either 2 or 8 into the calculator instead of 4. With the two subs you have now, you probably are running them parallel/parallel to 1 ohm. Adding the third sub will give you 2.67 ohms with series/parallel.....a lot easier on the amp. The added sub (cone area) will give you a couple db but the higher load on the amp will make it produce less power. You'll end up with about the same db as you had before but the amp will run cooler and with better specs. Any mono amp will operate fine into a 2.67 ohm load.
Posted By: wrathchild281
Date Posted: March 20, 2005 at 12:05 PM
ok thanks but hey i had a jbl600.1 pushing the 2 subs and now i just bought another sub and im buying a jbl1200.1 amp. So stevdart wouldnt that make it louder?
Posted By: stevdart
Date Posted: March 20, 2005 at 12:14 PM
That JBL amp isn't rated to 1 ohm, is it? You must have had those subs at a 4 ohm impedance. Going with a more powerful amp, a lower load at 2.67 ohms and the addition of a third sub will most definitely be louder.
Posted By: wrathchild281
Date Posted: March 20, 2005 at 12:30 PM
no it is stable at 1ohm i am assure of that. So now what size amp would you recommend? And how much power would be gettin from a jbl1200.1 at 2.67ohms?
Posted By: DYohn
Date Posted: March 20, 2005 at 12:34 PM
JBL amplifiers are not rated at 1-ohm because the manufacturer will not warranty them if you operate at 1-ohm. Most of them will remain stable at 1-ohm, but not all of them. A BP1200.1 (if you can still find one, the BP600 and 1200 are both discontinued models) should output about 1000-1200 watts at 2.66 ohms. ------------- Support the12volt.com
Posted By: wrathchild281
Date Posted: March 20, 2005 at 12:35 PM
so would you guys recommend i bump up to a mtx 1500D amp? or stick with the jbl1200
Posted By: customsuburb
Date Posted: March 20, 2005 at 12:44 PM
Yes they are 1 ohm stable... The older BP series (BP-600.1, 1200.1, 300.1 and 150.1) are all 1 ohm stable, but will output the same amount of power at 1 ohm as it would at 2 ohms. Features - High-Efficiency Switching Power Supply
- "Direct Connect" Terminal Block
- 2 or 4 Channel Inputs Allow for Non-Fading Bass
- Full-Size Die-Cast Aluminum Chassis
- Variable Low-Pass Crossover
- Variable Bass Boost
- 2-Ohm Optimized, 1-Ohm Stable
That's from sounddomain's site: https://www.cardomain.com/item/JBLBP1501Z You won't need a 1 ohm stable amp though because you can wire all three of them for 2.66 ohms like DYohn said. 
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Posted By: wrathchild281
Date Posted: March 20, 2005 at 1:35 PM
ok so would you guys recommend the mtx 1500D amp which is 1500 watts at 2 ohms or the jbl1200.1 which is 1200 watts at 2 ohms? thanks
Posted By: DYohn
Date Posted: March 20, 2005 at 1:52 PM
Your speakers are rated for 450 watts so the JBL amp is a safer match, but the two probably actually perform pretty much the same. ------------- Support the12volt.com
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