Need some help with this. I have a Goliath II 4X10s and a home brew 15 cab both are 8ohms. I am using a Hafler power amp with a BBE preamp currently. Im in the market for a replacement amp but the majority of used stuff tends to be 4 ohms. I know I can rewire the 4X10 to 4 ohms but what happens to the max power they can handle, and what to do with the 15 cab? Any advice would be welcome.
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Ohms dilemma
- Thread starter generation land
- Start date
Just how do you propose rewiring your 8Ω 4x10 to make it 4Ω?? That would be a neat trick!
Paul
Paul
Well as you can gather B-string I dont know much about this stuff, thats why I have asked for help.
Not beating on you Bro! I just like to avoid +1's and let others share their help and expertise as well. 
Speakers don't care what Ohm rating you are pumping your Watts, I know it is a bit confusing but the lower the Ohms the easier it is for the head to push Wattage. Heads tell you what the minimum safe operating load is, and yes most are 4, this means that they can go down to 4 Ohms, 2 8 Ohms cabs add up to be a 4 Ohm load. So lets say your head can pump 300 Watts at 8 Ohms and 500 watts at 4. This means that if you have your 4x10 OR your 1x15 attached, your head will send up to 300 Watts to that cab. If you then attach the other cab to said head, you will get 250 Watts to each cab (500 Watts divided by 2 because you have 2 cabs to share the load). You can rewire a 4x10 to get it to become 4 Ohms (and no it is not by removing 2 speakers) but then if you add the 1x15 you get a 2.6 Ohm load and this is not a good idea. Even if you have a head that can handle a 2 Ohm load you would want to add another 8 Ohm 1x15 (making the total load 2 Ohms) rather than run at a 2.6 Ohm load. I hope this helps you out man. Keep your head up it all gets easier. Cheers.
Thank you Kosmicwizard, I am starting to get the idea. So now I am looking for a good used 4 ohm head for around $300. Any recomendations?
2.6 ohms is not a problem; it just means you don't quite get as much power as you would at 2 ohms. In the case of an 8 ohm cab in parallel with a 4 ohm cab, it also means the 4 ohm cab gets 2/3 of the power available and the 8 ohm cab gets 1/3, roughly speaking.
There is really no practical way to rewire an 8 ohm 4-10 to 4 ohms.
There is really no practical way to rewire an 8 ohm 4-10 to 4 ohms.
It not easier for solid state amps to produce higher power with the lower number in ohms, it actually causes more heat and is harder on the output devices. But that is the nature of solid state amps and the design limits ("min." load in ohms) is determinted by the designer and componets used.
I can see no way of rewiring a 4 speaker 8 ohm cab to 4 ohms with the existing drivers.
