Nope. The choices are 1/2 ohm, 2 ohms or 8 ohms, not 4 ohms.
This is not rocket science Jesse. Let's learn, shall we? For two speakers or subs it's very simple to calculate the total impedance if you've had 3rd grade math.
Step 1, wiring dual voice coils, two options:
VC's in parallel – 2 ohms divided by 2 voice coils = 1 ohm per sub
VC's in series – 2 ohms times 2 voice coils = 4 ohms per sub
Step 2, wiring two subs together from options above:
4 ohm subs in parallel – 4 ohms divided by 2 subs = 2 ohms
4 ohm subs in series – 4 ohms times 2 subs = 8 ohms
1 ohm subs in parallel – 1 ohm divided by 2 subs = 1/2 ohm
1 ohm subs in series – 1 ohm times 2 subs = 2 ohms.
Note: this simple method only works for two subs. Three or more subs is more complicated. Another point. You can always connect a higher impedance load than the minimum required by an amplifier, but not a lower one. So, if your amplifier is not stable below 4 ohms (typical of a 2 channel amp in bridged mode), then from the options above the 8 ohm configuration is the only one that will work.
What the impedance (think resistance) of a speaker does is regulate the total flow of electricity through the amplifier. If you lower the impedance (i.e. the resistance to the flow of electrons), the circuitry must be able to handle the increased current flow, which among other things creates a lot more heat..
(Congratulations. You have just completed this mini-course and you're now an audio genius compared to the average person who posts questions here)
If you mean your amp needs a 4 ohm load to satisfy its stability, you cannot safely use less than a 4 ohm load on it. Your choice is to wire the voice coils for higher than 4 ohms impedance.You cannot make four 2 ohm inductors into a 4 ohm total. The closest you can get is 5 ohms; one speaker wired parallel for 1 ohm and the other series with itself for the other 4 ohms, then those two speakers in series with the amp.
Hi a 4 ohm load is always better than a 2 ohm load.
No. It's not possible to combine two 2-ohm DVC subs to make a 4-ohm load unless you leave two coils disconnected, which is not recommended.
Yes, but only if you wire them separately, in-series to themselves, on their own channels with a 2-channel amp.