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Add another sub

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=7717
Printed Date: May 13, 2025 at 3:53 AM


Topic: Add another sub

Posted By: sideburns
Subject: Add another sub
Date Posted: January 06, 2003 at 6:20 AM

Hello everyone,

Just a quick technical question. I have a Kenwood 5 channel amp (4x80, 1x240 max power, 4x40, 1x120 RMS at 4 ohms) powering two 5 inch components, two 6x9s and a 150 watt (RMS) 10" sub. I've just read in the manuals supplied with the equipment that the the RMS power of the sub must be higher than the max power of the amp which would mean that my amp is too powerful for the sub. Have I misread this?

Does this therefore mean that I could add another identical sub wired in parallel to 2 ohms (the amp is 150 RMS at 2 ohms) thus bringing the combined power of the subs to 300Watts RMS? or would the whole thing explode or make the subs too powerful for the amp to drive them. Is it perhaps a better idea to replace the sub rather than add another? 

Please help as I don't want to set my car on fire!! 




Replies:

Posted By: demeanor
Date Posted: January 06, 2003 at 5:42 PM

hello sideburns...

first of all...try asking the same question to "the12volt" or "velocitymotorsports" ...these guys have their ducks in a row!...not to down the rest of the forum...sorry, but a lot of people happen to disagree as to having ONE amp running their entire system...a lot is for prefference, others lack of / or too much knowledge.   i came accross the same predicament with a sony ex 5 ch amp, and i love it.  no complaints so far.  but as your question...the reason why you would want to have the rms of the sub higher than that of the amp is so that  you won't blow them on a hard note.  the amp you're describing is not "too" powerful for that sub (be sure that it's true rms rating on that sub) but remember that you can turn down the gain on the amp. 

as i understand it... when you hook up subs in series or parallel, their rms value still the same ...it doesn't add up...it just takes the amp more (series) or less (parallel) effort to move the subs.  when you take subs in a parallel setup your making their impedance lower, therefore the amp will push more watts through them while running hotter because of more current being pushed out of it.  when theyr ran in series, the impedance becomes greater, therefore less watts going through the subs, the amp runs not as hot, but not as "loud" although it will last longer.   "Does this therefore mean that I could add another identical sub wired in parallel to 2 ohms (the amp is 150 RMS at 2 ohms) thus bringing the combined power of the subs to 300Watts RMS? "  in this setup you will still push 150 watts rms per sub, with a max of 240 watts @ peak.  this ammount should not blow the subs...however if you have the gain at max, you will get distorted sound out of your subs.  i have 4 DVC 10" running out of my sony, as well as two 6˝ 's and two 6*9 and no complaints yet.

what is the peak of the subs? brand?

hope  this definition cleared up something if not write back and let me know...i'll get better info to provide you with.

good luck with your set up.



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It's better to ask a "STUPID" question...than to know a "STUPID" answer. :-)




Posted By: sideburns
Date Posted: January 07, 2003 at 9:18 AM
I think on the strengths of what you've told me, I'll stick with one sub. I like the 5 channel setup as it's more simple and doesn't steal all the boot space in my small car, and I'm looking for an all round good quality of sound rather than full on volume (although I do like it high sometimes!!). I think next on the list is better RCAs and a power cap, with upgraded speaker and power cabling all round. Any suggestions/recommendation as to good brands??




Posted By: demeanor
Date Posted: January 07, 2003 at 3:02 PM

price wise...not sooo good...kind of high end but Rockford fosgate kits are pretty good, and if you fancy, you might actually go to a shop and buy their wire...the reputable ones carry the kits and have their particular brand as well.

good luck



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It's better to ask a "STUPID" question...than to know a "STUPID" answer. :-)





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