8 ohm head, 4 ohm cabs

[Sky Blue Lou]

It probably makes sense for a single speaker cab. If the amp is 8/16 you can go series. I have an amp like that. How often would it come into play with 2 or 4 speaker cabs?


lou

 

[c7sus]

Is that standard on amps? They don't ever wire dual outputs in series?


lou

If you wired them in series and blew a speaker on the first out you'd lose the second out.

 

[Sky Blue Lou]

If you wired them in series and blew a speaker on the first out you'd lose the second out.

Ahhhh....good point. And the whole amp as well, eh? Makes sense.


lou

 

[mcmetal]

NO! Cab's are typically connected in parallel when you daisy-chain several cab's. Plugging into 2 4-ohm cab's would show your amp a load of 2 ohms. That will be very bad for you amp, it's suck waaay to much current and probably fry your amp.

What you need to do is get those 2 4-ohm cab's wired up in SERIES. 2 4-ohm cab's in series would be 8 ohms.

OR probably easier - re-wire the speakers in each cab so each cab is 16 ohms instead. A 4-ohm 8x10 is probably all 8-ohm speakers wired as 4 sets of (2 speakers in parallel to 4 ohms). Those 4 2-speaker sets are wired series/parallel to grand total 4-ohm load. What you need to do is wire those 4 2-speaker sets in series to produce a 16-ohm cab. THEN you can daisy chain the 2 cabs in parallel to achieve the 8-ohm load load your amp wants.

He didn't want suggestions!!!

 

[suprstar]

What's the safest way to connect them to a head (to simplify, how many ohms does my head need to be to safely run two 8x10s in PARALLEL? SERIES? TWO OUTPUTS, TWO CABS. One output, two cabs.

If you can't connect them in series (and you probably cant), then there is NO safe way to connect all that gear. You can't even safely connect ONE of those cabs to your amp.

Unless you can rewire, then those cabs could be perfect for that amp.

 

[Farview]

It probably makes sense for a single speaker cab. If the amp is 8/16 you can go series. I have an amp like that. How often would it come into play with 2 or 4 speaker cabs?


lou

Well, if you had four of them, you could make an 8 ohm load by wiring two sets of two speakers in series and plugging the sets into the two amp outputs (parallel)

If you just used two cabinets and your amp didn't go down to 4 ohms, you would wire the two in series to get 16 ohms.

I see what they are trying to do, but how many people are going to bother with 4 separate cabinets instead of one. They could have just made each cab 16 ohms, then two would be 8 ohms and 4 would be 4 ohms.