1960a Marshall cabinet (300watts) - 8ohms or 16?

  • Searched the forums but unfortunately can’t find a thread.


    Was experimenting with the Kemper the other night. My cabinet can run 4,8,16 ohms.


    I understand the Kemper is 600w at 8ohms and 300w at 16ohm.


    I know the whole gallon of milk into a half gallon jug thing, where you obviously can’t fit the milk theory.


    Switching to 8ohms gave the Kemper more “guts”, drive and power over the 16ohm option, but my concern is will I destroy my cabinet if I play at 8ohms?


    Trying to keep up with a guitarist who has a 5150, a drummer who bashes the drums and a bassist who brings an 8x10 to shows. Past 2 shows the crowd asked me to raise my volume, but I was at -13db!!



    Thanks for the assistance!

  • If you run at 8ohms you will be fine AS LONG AS YOU DON’T TURN UP TOO LOUD to use more then 300w worth of power. If you stick with 16ohms you should be safe even if you get carried away. I would stick with 16os to avoid the risk of getting a little over enthusiastic is the band as really loud. If you aren’t loud enough at 300w into 16ohms the problem isn’t that you are too quiet. Everyone else is too loud! Get them to turn down.

  • Thanks for the reply. Appreciated. I’ll stick to 16ohms for safety purposes.


    I just wish I knew how loud I could go if needed without having to worry about blowing speakers. I keep it around -13db at 16ohms and I’ve come to the conclusion my drummer must be deaf. He is the one that complains the most, and the cabinet is directly next to him.


    I wish the Kemper had a 4/8/16 selector switch like my 5150, but the Kemper is just better overall (and lighter!)

  • Aren't you only playing through two speakers when switching to 8ohms on that cabinet? There have been lots of discussions about the internal amp not being loud enough for some players. Check your various volumes, it's easy to miss one, or bring up the mids if your tone is scooped. And you don't need an ohm selector switch on the Kemper, I guess you can say it self selects to whatever you're plugged into.

  • It’s just 1 cabinet, 4x12. It just doesn’t have the “guts” or drive on 16ohms / 300watts


    Actually played a show this weekend and the cab that we all used was set to 8ohms and my sound got compliments with the fullness and drive it had.

  • Yeah, he's only running through two speakers but if it works, it works. It is possible for the KPA to run at 4 ohms, but it's risky without an internal cooling fan. That's probably why bass players have largely avoided the PowerHead

  • Yeah, he's only running through two speakers but if it works, it works. It is possible for the KPA to run at 4 ohms, but it's risky without an internal cooling fan. That's probably why bass players have largely avoided the PowerHead

    I run my power rack into the 16 ohm input of a 1960A, there should be no reason at all why it's not producing enough volume. My guess would be that gain staging somewhere in the KPA itself isn't optimized for full output if somebody isn't getting enough volume with 300 watts. A 100 watt Marshall tube amp into that same cab is going to be louder than snot, and pushed hard it's still "only" delivering upwards of around 180 watts.

  • Try upping the 'power amp boost' in the output section. I had the same trouble (with my 1960 16ohm). That sorted it - loads more oomph

  • I've driven my 4 x12 at both 4 ohms and 16ohms ( I rewired), and could not tell the difference at all. Volumes broadly the same.


    I also have no problem with volume and we play loud. As above, make sure the power amp boost is full on...you'll be going some to blow a 4 x12...