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Complicated 4-sub wiring problem

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=54699
Printed Date: May 17, 2024 at 3:48 PM


Topic: Complicated 4-sub wiring problem

Posted By: Andyq_8
Subject: Complicated 4-sub wiring problem
Date Posted: April 26, 2005 at 9:58 PM

ok i have a friend who has the Hifonics ZX1000 amp... he has 4 Fosgate 15" HE's and they are all 8 ohm subs... now wiring them all into parallel would be a 2 ohm load, yes... but is it possible to basically think of it as 2 subs and make it like a "Dual 8 ohm subs"? As if each set of subs is 1 subwoofer...wiring one sub to the other...so one subs - to the others + and then do they same for the other 2 subs and put the 2 together into a 4 ohm load? Amp pushes 1000w at 4 ohms bridged which is perfect for all 4...confusing? hell yes...please help thanks!



Replies:

Posted By: Poormanq45
Date Posted: April 26, 2005 at 10:10 PM
If I understand you correctly, you are asking if you can wire 2 of the subs in series, and the other 2 subs in series, and then wire them in parallel to the amp, correct?

If so the overall ohm load would be 8Ohms.

8+8=16. 8+8=16. 16/2=8.

Can tha tamp handle 2Ohms? If so then wire all of the subs in parallel.

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Posted By: Andyq_8
Date Posted: April 26, 2005 at 10:16 PM
actually i would like to make it a total 4 ohm load at the end...the amp is stable at 2 ohms but not bridged...so i can only go 2 ohms to one channel... which is 500 for each channel...(not the amount of watts desired..) but 4 ohms bridged is 1000watts so i didnt kno if it was possible mixing all the parallel/series combinations together to make it work....thanks for the help man




Posted By: Poormanq45
Date Posted: April 26, 2005 at 11:35 PM
here's the combinations you can get with those subs:

2 in series = 16ohm
2 in parallel = 4 ohms
4 in series/parallel = 8 ohms
3 in parallel, one in series = 10.79167Ohms
4 in parallel = 2 Ohms
4 in series = 32 Ohms

Now, you can add resistors to the circuit to make just about any Ohm load you want. You tret them the same as if they were speakers when calculating the Ohm load..i.e a 4 ohm speaker in series with a 4ohm resistor = 8 ohms. parallel would = 2 Ohms.



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Posted By: auex
Date Posted: April 26, 2005 at 11:50 PM
Your not getting 4 ohms. Also don't mix the the subs wiring 3 series and 1 parrallel. And don't use resistors to trick the amplifier. Any power you gain will go to the resistor and doesn't do anything.

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Posted By: vinman75
Date Posted: April 27, 2005 at 1:51 AM
Also if the amp is 1000w at 4ohm mono. and 500 w a channel at 2ohm stereo then it is the same power. What I am saying is they will only see 250 a piece either way you do it.




Posted By: stevdart
Date Posted: April 27, 2005 at 6:47 AM

When you connect two subs together, the impedance changes.  If they are paralleled, the impedance is halved, and if they are linked in series the impedance is doubled.  You can't create a DVC hybrid using two SVC woofers and maintain the impedance that one of them presents by itself.  So, with four SVC 8 ohm woofers you cannot connect to that two-channel amp and get 1000 watts.  Pair the subs like this:

posted_image

...and connect a pair to each channel.  Each sub will receive 125 very clean watts.  If the subs are these RFP4815 then that is the appropriate amount of power to put to them.  It will be a total 500 watts but with a proper enclosure this will be a killer setup.



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Posted By: Captanham
Date Posted: April 27, 2005 at 7:48 AM
yea there really isn't a way to draw full power out of that amp like that, why did you get 8 ohm subs anyways? didn't they know that would be a nightmare? haha

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Posted By: Poormanq45
Date Posted: April 27, 2005 at 1:54 PM
8Ohm subs efficiency rating is actually 3dB higher then that of a 4Ohm sub with the same rated efficiency.

There are a few other benefits, but I just had a brain fart posted_image

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Posted By: Captanham
Date Posted: April 27, 2005 at 3:30 PM
really? i did not know that, well then if it's a more effecient sub, it might be just as loud as it would be if they were pulling all the power out of the amp, and also with the amp not being strained so much you will get less thd, so you might actually end up with a pretty good sounding system,

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Posted By: Andyq_8
Date Posted: April 28, 2005 at 11:42 AM
well i bought the 4 8 ohm subs because it would wire to 2 ohms... which my concept amp pushes 900 watts @ 2 ohms so a good 225 to each sub... jus a bit over RMS rating on the subs... had them all in ported boxes...beat like a sum b**** thats for sure... i absolutely love my Avalanche 15 now though... about the same in bass low notes are better but SQ is outstanding thats for damn sure... didnt know if anyone would have an idea on how much the ZX1000 amp would push at 8 ohms bridged or 4 ohms per channel? thanks





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