8 ohm cabs, 4 ohm loads, and 1/4 jacks

agent77 · #1 11-10-2011, 09:59 AM

OK, so the only stupid question is the one you don't ask. I know that 2 8 ohm cabs connected to the same head will prouduce a 4 ohm load, but how do I connect the speaker jacks? For example: I have 2 1/4" output jacks on my head, and 2 1/4" input jacks on each of my cabs (no output jacks on the cabs). Also, could I get a 4 ohm load from 2 8ohm cabs that have only 1 1/4" jack, like the GK MB cabs?

Warrior_Bass · #2 11-10-2011, 10:10 AM

Quote:

Originally Posted by agent77

I have 2 1/4" output jacks on my head, and 2 1/4" input jacks on each of my cabs (no output jacks on the cabs).

Using each output jack on your head to each of your cabs will bring the load to 4 ohms. Using one output jack to one of your cabs, and out of that cab to your other cab will also bring the load to 4 ohms.

Quote:

Originally Posted by agent77

Also, could I get a 4 ohm load from 2 8ohm cabs that have only 1 1/4" jack, like the GK MB cabs?

Yes, see above.

tjh · #3 11-10-2011, 10:54 AM

... just to expound a bit on Warriors great answer ... the type of connection used has no affect on impedence, and the second way that he mentioned is what is commonly referred to as "daisy chaining" cabs (going from one cab to another) ... running from the head to cabs in either of these conventional manners is considered running in "parallel", and connecting either way that Warrior explains net the same results .... BTW, the reason there are two 1/4" jacks on the back of your cabinets is to run one cable in, and one cable out, it doesnt matter which is used when only one cable running in ... the only caveat that I would add, is make sure you use SPEAKER WIRE, and not instrument cable to make your connections to the cabinets ...

tgriley62 · #4 11-10-2011, 02:59 PM

So by "daisychaining" you would be able to connect four 8ohm cabs to one head & still be at 4 ohms total, correct?

basscooker · #5 11-10-2011, 03:04 PM

NOOOOOOOOOOOOO

basscooker · #6 11-10-2011, 03:04 PM

please don't do that

skychief · #7 11-10-2011, 03:06 PM

Quote:

Originally Posted by tgriley62

So by "daisychaining" you would be able to connect four 8ohm cabs to one head & still be at 4 ohms total, correct?

No, that would be 2 ohm load.

HolmeBass · #8 11-10-2011, 03:06 PM

Quote:

Originally Posted by tgriley62

So by "daisychaining" you would be able to connect four 8ohm cabs to one head & still be at 4 ohms total, correct?

No, incorrect. Assuming the standard, which is parallel jack wiring, whether you daisychain or run both cabs off of the output jacks on the amp MAKES NO DIFFERENCE- all of those jacks are wired in parallel, the ones on the cabs and the ones on the back of the amp.

PuffusMaximus · #9 11-10-2011, 03:16 PM

i believe with 4 8ohm speakers you could get an 8 ohm load if you connect your two outputs on the head to one speaker each, and then "daisychain" those two speakers to another one each

HolmeBass · #10 11-10-2011, 03:17 PM

Quote:

Originally Posted by PuffusMaximus

i believe with 4 8ohm speakers you could get an 8 ohm load if you connect your two outputs on the head to one speaker each, and then "daisychain" those two speakers to another one each

No, not on 99.99% of bass gear you won't. They'll all be in parallel, and you net a 2 ohm load.

silky smoove · #11 11-10-2011, 03:18 PM

Quote:

Originally Posted by PuffusMaximus

i believe with 4 8ohm speakers you could get an 8 ohm load if you connect your two outputs on the head to one speaker each, and then "daisychain" those two speakers to another one each

Nope

PuffusMaximus · #12 11-10-2011, 03:25 PM

this is my understanding, please tell me if im wrong. two 8 ohm speakers, one per output, would be in parallel and give a 4 ohm load. connecting a speaker into one input, then chaining another speaker to that one would put them in series giving a 16 ohm load.
???

HolmeBass · #13 11-10-2011, 03:28 PM

The jack connections on the vast majority of speaker cabinets are also wired in parallel, just like the output jacks on the back of your amp. So daisychaining does not connect the speaker cabinets in series, it connects them in parallel.

Now if you're talking about straight wiring of speakers themselves, then of course if you wire them in series - "+" on one to "-" on the other, then the remaining "-" on the first and "+" on the second speaker back to the amp - then the nominal impedance will add.

PuffusMaximus · #14 11-10-2011, 03:31 PM

so what would be the outcome of connecting one speaker and chaining one to it? or did you already answer that in the first line?

Passinwind · #15 11-10-2011, 03:31 PM

Quote:

Originally Posted by PuffusMaximus

this is my understanding, please tell me if im wrong. two 8 ohm speakers, one per output, would be in parallel and give a 4 ohm load. connecting a speaker into one input, then chaining another speaker to that one would put them in series giving a 16 ohm load.
???

For the sake or argument let's say the second jack on that cab is in series. When nothing is plugged into the second jack there is an infinite load in series with an 8 ohm one. So the total load is infinite and you hear nothing. Is that your experience?

**neoman09** · #16 11-10-2011, 03:31 PM

My Carvin BX-500 head is 4 Ohms, can go down to 2 Ohms and even has a switch on it for 2 Ohms, in back.

Anyway my question is, for a 4 Ohm head, what happens if I plug it into a 8 Ohm cabinet ?

HolmeBass · #17 11-10-2011, 03:33 PM

Quote:

Originally Posted by PuffusMaximus

so what would be the outcome of connecting one speaker and chaining one to it? or did you already answer that in the first line?

Yes I answered that in the first line- and think about what Passinwind said, it makes a lot of sense.

HolmeBass · #18 11-10-2011, 03:33 PM

Quote:

Originally Posted by neoman09

My Carvin BX-500 head is 4 Ohms, can go down to 2 Ohms and even has a switch on it for 2 Ohms, in back.

Anyway my question is, for a 4 Ohm head, what happens if I plug it into a 8 Ohm cabinet ?

No problem, it's ok on most solid state power amps like your Carvin. I would run the Carvin on the 4 Ohm setting for anything other than 2 Ohms- in fact, isn't it listed as 4ohms and higher or something? Also check your owners manual, I am sure the operation of that switch is covered in there.

PuffusMaximus · #19 11-10-2011, 03:36 PM

Quote:

Originally Posted by Passinwind

For the sake or argument let's say the second jack on that cab is in series. When nothing is plugged into the second jack there is an infinite load in series with an 8 ohm one. So the total load is infinite and you hear nothing. Is that your experience?

what makes it an infinite load?

BurningSkies · #20 11-10-2011, 03:50 PM

Quote:

Originally Posted by Passinwind

For the sake or argument let's say the second jack on that cab is in series. When nothing is plugged into the second jack there is an infinite load in series with an 8 ohm one. So the total load is infinite and you hear nothing. Is that your experience?

Is this why my amp is so quiet?