Two 4 ohm cabs in series = rise in impedance???

Be careful bro. That would actually be a 2 ohm impedance. Not 8. Unless your all tube head can handle that kind of load your gonna fry your amp. DON'T DO IT!!!

 

Even run in series, from one cab to another, it equals a 2 ohm load. Seriously. Go to your search function and look for the info you request. There are lots of players here that will tell you the same. Just wait for other responses before you try what your asking about.

 

No, the OP is right. Two 4-ohm cabs in series will present a 4-ohm load to the amplifier.

If they were in parallel, it would be two ohms.

My only warning about a series setup is that if you ever forget to use the special series cable, you're going to fry the amp before you know it. (Though most amps will start out working OK, then shut down after a while. This could be a real annoyance at a gig.)

EDIT: The first sentence should read "...present an 8-ohm load..." Can't believe I mistyped that.

 

I'd be wary of the crossover, because I have heard before that series connections and crossovers don't mix.

But yeah, series connection of two 4 ohm speakers will certainly yield 8 ohms. Hence the purpose of a series cable. If one was to not use a series cable, sure, it'd be 2 ohms, but he's using a series cable.

EIGHT OHMS.

 

Isn't resistance in series additive and parallel is R1R2/(R1+R2)?

 

two 4ohm in parallel is indeed 2ohms, but the OP is combining the cabs in series, not parallel, hence the impedance will be 8 ohms. The OP is right.

 

I believe the cab with the tweeter will have a shift in crossover frequency due to the 4 ohm load in series with it. Impedance changes affect the crossover frequency.

Yes you ARE correct that using a special SERIES cable to connect two 4 ohm cabs will make an 8 ohm load to your amp.

 

So tell me how it is actually done. I'm not disagreeing just curious. Would I be able to run say four 112 cabs rated at 8 ohms and get just a 4 ohm load?

 

No. 2, 8 or 32 ohms would be your choices.

2 ohms parallel.
32 ohms series.
8 ohms series/parallel.

 

Two 4 ohm loads in series equals 8 ohms.

 

So it is a special cable and would only yeild the 8 ohm load off of two 4 ohm cabs? Thanks B. Sorry for the miss info Muck.

 

I don't claim to be a crossover expert, but my understanding is: if a speaker in series was a pure resistor, the crossover would not be affected. However, speakers are inductors in the real world. So adding an inductor in series will block high frequencies a tad.... but I'm not much of an expert on LC networks

 

i have not heard of such a cable...where wence doth one aquire said witchcraft??