Bass Cabs Ohm Question

[jaybyname]

Hi all, some advice if possible.

Just purchased a GKMBE210 Top cab and a GKMBE115 bottom cab and just noticed that the 15 is a 4ohm cab AND THE 2X10's are 8 Ohm. My head (Lines 6 HD750) states at the back use a 4ohm single or 8ohm if pairing. Any ideas what I can do? Can I power both from the head with no problems? Do I need to swap cabs. I bought the 2x10 new and the 15 used.

Dont really want to return as I got it real cheap and its perfect condition

[funkinbottom]

I would not run both cabs together. Your best bet would be another 8 ohm cab.

[jaybyname]

I knew there'd be a problem!

[RickenBoogie]

Get rid of the 4 ohm 15, as that's a useless cab anyway. Find a good 8 ohm 15 if that's the plan, but understand that a 2nd identical 210 is the better plan.

[iualum]

Originally Posted by RickenBoogie

Get rid of the 4 ohm 15, as that's a useless cab anyway. Find a good 8 ohm 15 if that's the plan, but understand that a 2nd identical 210 is the better plan.

Yep, sell the 15. If you got the 210 real cheap, then another one (also real cheap?) is the best bet.

[jaybyname]

Ok, another option.

Back of my amp head states 4Ohm single (mono) or 8Ohm pairing.
Could I connect a 2x10 4Ohm Cab to the 4Ohm amp input and 'daisy chain' to anoth 4Ohm 1x15. Mono Stack! Technically, would this be the amps full output at 4 Ohms.

Or, 8Ohm 2x10 cab into amp input and 'Daisy chain' to the 4Ohm 1x15 cab

Amp head is a Line 6 HD750

[SteveHeissner]

You'll need two 8 ohm cabs to get 4 ohms. Mixing the 8 and 4 ohm cab will give you a total impedance of less than 4 ohms.

[kingkeld]

Jay, I posted pretty much the same question a couple of days ago:

Understanding the Ohms (yes, again!)

I have one 8 Ohm cab, and I was looking into 4 Ohm ones.

The solution for me was buying another 8 Ohm.

[jaybyname]

But....the amp head puts out 750w at 4 ohms which is ample power to move 3 speakers (2x10,1x15) in series. So diasy chaining, I thought would be ok.

Amp to cab, cab to cab. How does the amp know its powering 3 speaker across 2 cabs

[Downunderwonder]

The connectors on amp and cabs are always wired parallel. All cabs contribute to lowering the impedance load wherever they may be connected. Your amp has a minimum loading of 4 ohm.

Get rid of the 4 ohm 1x15 and get another 8 ohm 2x10, a vertical set of tens is a great rig.

[Bassmann1968]

Your amp knows the impedance of those cabs
Your amp can handle a load of 4 ohm. A 4 and a 8 ohm cab together
are 2.66 ohm. So the load is to high and will damage your amp.

[Jbassrockboy]

It doesn't but you will know when you blow the head. Take the wisdom of advice offered by the other players who took the time to respond.

[Idroppedit]

Ohms are the measurement of resistance or load. The amp will not know has many speakers but it will recognize what load you are putting on it. The ~2ohms you are wanting to put to your amp could cause you to fry something. Proceed with caution, I think we all recommend not proceeding with an 8/4 ohm combo altogether. Get rid of the 4 ohm cab and get an 8. The price to replace the amp isn't worth the risk.

[greencow]

The head puts out 750w at 8 Ohms
You have 2 cabs.
One is 4 Ohm load containing one 15" speaker with an impedance of 4 Ohms
The second is an 8 ohm load containing 2 speakers, either 16 Ohm coils parallel or 4 Ohm coils in series.

The amplifier sees the cabinet as a single load and doesn't really care what's inside it.

As to "Daisy Chaining", The connectors on your amplifier are parallel. Connecting Amplifier->Cab->Cab will also leave the cabinets connected parallel.

To calculate the total load for two loads connected in parallel:
Rt = (R1 x R2)/(R1 + R2)
connecting an 8 Ohm and a 4 Ohm cabinet to the amplifier will result in a total load of less then 4 Ohms and the amplifier is only rated safe at a total load of 4 ohms or higher.

[jaybyname]

Confused myself thinking I could run 2 x 4Ohm cabs off the 1 4Ohm amp input. Making the amp think its just powering 1 x 4 Ohm cab with multiple speakers rated at 400w combined. I thought daisy chaining was the easy option.

I guess I was wrong!!

Great advice everyone. Seriously appreciate it.

[jaybyname]

Hi all, following on from this previous thread. I t apperas im in a catch 22 situation.

Not sure wether to buy a 4x10 4ohm for the 4 ohm input, or
2 x 8ohm cabs to use in the 8ohm inputs.

I ask as Im worried that if I buy a 4ohm cab and decide at a later date that I want an extension cab - im stuck as I wont be able to extend on the 4 ohm load. So ill have to buy 2 new cabs at 8 ohms!!

How loud/deep will a 4x10 cab sound by just connecting to the 4 ohm unput? Would this be sufficient?

Sorry for the questions

[Downunderwonder]

Easy way to get a great sound is to stack two 8ohm 2x10.

The amp output is omnivorous. So long as the total load is over 4ohm you're good.

[dincz]

Originally Posted by jaybyname

Not sure wether to buy a 4x10 4ohm for the 4 ohm input

Where the stuff comes out of the amp is the "output".

[jaybyname]

Output!...sorry.


In ref.

(4 ohm single or 8 ohm pair only)

So plugging a single 8 ohm cabinet into one of the outputs would be quiet?

[CL400Peavey]

Originally Posted by jaybyname

So plugging a single 8 ohm cabinet into one of the outputs would be quiet?

Not at all, depending on the speaker. The difference in volume between an 8 Ohm cab and a 4 Ohm cab is pretty negligible.