subwoofer wiring, series/parallel conundrum

[supermanotorious]

I dunno if it's possible, for starters I want to calculate total impedance, getting it as close to, but not lower than 2ohm

I have four 4ohm DVC subs and two 2ohm DVC subs, six speakers total, can I wire them all together to get the impedance I'm seeking?

couldn't the 2ohm subs be wired in series themselves to appear as 4 ohm subs?

 

[Bbqjoe]

I dunno if it's possible, for starters I want to calculate total impedance, getting it as close to, but not lower than 2ohm

I have four 4ohm DVC subs and two 2ohm DVC subs, six speakers total, can I wire them all together to get the impedance I'm seeking?

couldn't the 2ohm subs be wired in series themselves to appear as 4 ohm subs?

I'd be careful, there's at one least one law about this.

 

[maxpower49]

Ignore all of this I was wayyy off base and made a comment after too long of a work day and too little thought

However you can still use a multi meter to check the ohm rating at the end of the wire before hooking it up so I will stand behind that

Yes you can wire up the two ohm woofers to show four ohms then just connect everything else in parallel and it should remain at the two ohm range. Just treat the pair of two ohm speakers as a single four ohm. just make sure to test the ohm rating with a multi meter before hooking everything up to make sure before things get smokey

 

[itsid]

Yes you can wire up the two ohm woofers to show four ohms then just connect everything else in parallel and it should remain at the two ohm range. Just treat the pair of two ohm speakers as a single four ohm. just make sure to test the ohm rating with a multi meter before hooking everything up to make sure before things get smokey

WoW that is so WRONG!!

yes, you can add the two ohms in series to add up to 4 ohms..
that much is true..

resistance in parallel is a whoooole different kind of animal though!

YOU CANNOT just connect them in parallel them and think they stay at 4Ohms.

Resistance in parallel add the following way:

1/R1 +1/R2 +1/R3.. = 1/Rtotal

which for a set of 5 times 4Ohms (one of which two two ohms in series) is
1/1.25 = 0.8 Ohms (far from four isn't it?!)

NOW, that being said..
impedance is at a certain frequency (audio frequency in your case)
an 8Ohm speaker can drop it's electrical resistance to four Ohms at low notes...
Woofers.. typically see low notes, therefore the ONLY sane way to get this dialed in correctly is to verify the impedance at a certain tone
(say 35Hz) just to make sure you're not going to stress it below it's resonance frequency.
Above that it's impedance will only increase (from said 4Ohms upwards to something around 25 or 30 ohms typically for higher notes)
unpowered electrical resistance is neither safe nor accurate to predict what the speakers will do when stetsasonic is talking all that jazz

[edit]
I'm not sure if it's as easy as adding another 3.2Ohm resistor in series tbh..
electrically that'd work.. from an acoustic view that could render the woffers pointless though *shrugs*

'sid

PS only resistance calculator for your convenience:
http://www.sengpielaudio.com/calculator-paralresist.htm

 

[supermanotorious]

since I recently bought some subs from Crutchfield so they did the math for me today:

1. each individual speaker's DVC was to be wired in series
2. then, divide the 6 into two groups, one 2 ohm and two 4 ohm subs
3. in each group connect the two 4 ohm subs in series then parallel connect the 2 ohm
4. speaker leads to the output of the 4 ohms in series and connect to the amp, this gives us 4.8 ohms
5. repeat steps 2-4 with the other group (essentially running both groups in parallel), now we're at 2.4 ohms

only thing is, I dont follow completely since the 10s are 2 ohm, the 12s and 15s 4 ohm

 

[supermanotorious]

and at any rate this was just an experiment, my 1000w amp split an perfect 6 ways is underpowering the big guys, just thought I would see what happened

 

[pRoFiT]

Ah yes subs! I can't hear anymore. So i took mine out. I use my 12's as a table now in the garage. One day i may re install and completely go deaf. I've got a whole cabinet of amps....