That equation is for two subs. For four 4 ohm subs you would need to use something like this:

(4 x 4) divided by (4 + 4) = 2 ohms

Then you would use the 2 ohms as one speaker in the next equation:

(4 x 2) divided by (4 + 2) = 1.3 ohms.

Then to get the total of four 4 ohm subs, you would use the 1.3 ohms as one speaker again in the next equation:

(4 x 1.3) divided by (4 + 1.3) = 0.98 ohms (1 ohm)

So the total load of four 4 ohm subs wired in parallel to the amplifier is 1 ohm.


This is the method i use anyway, any1 got summut better, test it in here :thumbs:

What about when 3 or 4 subs r involved.

Only if u hav the time tho, lol

Thats ok Adi was just defending myself, lol.

Thanx for that Richie, makes sense and put very simply.

that wasnt for u DC, but for people that dont know the basics....

Wire one dual 4 ohm sub in series to make 8 ohm, wire the other in parallel to make 2 ohm, wire them both in parallel to the amp to make 1.6 ohms.

To work it out use this:

(Total load of speaker 1 X Total Load of speaker 2) divided by (Total load of speaker 1 + Total load of speaker 2)

I obviously get all that simple stuff Adi its the wiring to dual 4's at 1.6 ohms i dont get, lol

Series = Add the Resistance's together.

2 x 2 Ohm coils in series is --- 2 + 2 = 4 Ohm Load

Parallel = 1/(1/Resistance A + 1/Resistance B)

So 2 x 2 Ohm = 1 / (1/2 + 1/2) = 1 Ohm

Get it???

yeah i'm very interested ... i've installed 2 basicish installs but this whole wiring thing and ohms is confusing the shit out of me :boggle:

Agreed.

Altho if u ever good bored at some point Richie it would be good if u cud make a post explaining wiring options other than just the standard series n parallel.

Am interest even if no1 else is, lol.

The closest you could get with that setup is 1.6 ohms, but lets not go there :lol:

You need a 1 ohm stable amp for that set up mate.

Whats ya budget and some1 might just recommend ya something

no u cant.

2x 4ohm coils mean eac sub can be wired to eiter 2 or 8 ohms.

2 of those subs can then be wired to either 1 ohm, 4 ohm or 16ohm, none of which are any good.

So NO!

alright everyone ... i was looking at gettin this kit :

amp - MRDM500 Alpine D class amplifier 1 x 900w - http://www.mcs-direct.co.uk/acatalog/MCS_DIRECT_Amplifiers_49.html

sub (2x) - RFP4215 12" Punch HE2 DVC (4 ohms x 2) Subwoofer with polyypropylene cone, BART foam surround, LXursion basket, consealer gasket, Rubber magnet boot, 250 watts RMS/500 watts peak. - http://www.mcs-direct.co.uk/acatalog/MCS_DIRECT_Subwoofers_58.html

all i want to know is if it is possible to run these 2 subs off the one amp? and because they are dual coil what will the wiring look like?

thanks
tim