Fusing my 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=63877
Printed Date: May 14, 2024 at 9:56 AM

Topic: Fusing my subs

Posted By: trixreppinva
Subject: Fusing my subs
Date Posted: October 05, 2005 at 9:29 PM

I just wired my subs in parallel and I need to know the right size fuse I need to fuse my subs. The rms on the subs is 200 and the ohms is 4. But when the two subs are wired in parallel the ohm load is 2. So I don't know if I should use the total ohm load which is 2 or the 4 ohms from the sub. So basically should it be

the square root of 200/4

or the square root of 200/2

So if anyone could give me a hand Id appreciate it

Replies:

Posted By: dwarren
Date Posted: October 05, 2005 at 9:39 PM

Don't fuse speakers.

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Posted By: Bmnicolosi
Date Posted: October 05, 2005 at 9:57 PM

i agree with dwarren, there is no need to fuse speakers

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If you say "I already know how", don't ask me a single question.

Posted By: stevdart
Date Posted: October 05, 2005 at 9:58 PM

Sure you can fuse speakers, dwarren. They're connected with a power wire, and any wire that carries amperage can be fused. It's just usually not done because you've taken the precaution of matching the speakers to the proper amplifier and setting gain correctly.

Use 2 ohms as your factor, which is the combined impedance of the two subs...using that because the subs are wired together. The nominal wattage of the subs is 200 X 2 or 400...so you are thinking in terms of using 400 watts and 2 ohms in your equation ( I = sq rt (P/R). But don't use the nominal wattage because there are going to be peaks in the signal that will blow the fuse. You should use something near the sub's peak rating and a slow blow fuse for this, and it will be just one fuse for the set of subs. It should never blow, because that would be a PITA!

And keep in mind the fusing will not protect the speakers from getting a clipped signal...but I figure you already know that.

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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: dwarren
Date Posted: October 06, 2005 at 1:09 AM

I said don't, never said you can't. posted_image

I thinks it's unnecessary to do so. The one exception is fusing tweeters. I have done this in the past for some "weak" tweeters that blew frequently. But subs, bah.

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