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Ohms - Don't yell at me

S

seand123

Jan 16, 2026
10
15
#1
Hi All,
I prefaced my subject as I'm sure this has been asked many times, but reading through the many threads, I couldn't get the answers I was looking for. So, don't yell at me :)

I ordered a markbass Little mark 58R, which is 500w RMS at 4 ohms. I also ordered the mb58r 2x10 xl speaker cab, which is rated at 400w. I had originally ordered the 8ohm version of the speaker cab, but guitar center sent me the 4ohm version by accident. My question is, aren't I going to be overloading the speakers if I plug this in, or is the 400watt speaker RMS rating for EACH speaker? Long story short, am I safe to plug in the 500w RMS @ 4ohm little mark into the 2x10 400w RMS cab @ 4ohm?

Secondly, the cab has two speaker inputs. Does this mean they're wired in parallel vs series? I would have assumed that it would have one wire into the cab for series operation.

Best,
 
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#3
Amp can make 500W at 4 ohms. 4 ohm cab is only rated for 400W. Yes you have enough power to destroy the cab.

The amp does not make 500W all the time. The power depends on how loud you try to play. If the speaker can easily exceed your volume requirements, it's safe unless you do something stupid or perhaps have an accident.

If the cab cannot meet your volume requirements, it's much easier to blow it up. The natural response when you need more volume is to turn up. But of course, you have no way of knowing when the power level exceeds 400W.

Should you return the 4 ohm cab and ask for the 8 ohm version you paid for. Maybe. If the goal is to eventually buy a second matching 8 ohm cab, most definitely. If the 4 ohm cab is loud enough and you have no desire to buy a second cab, perhaps not.
 
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#4
The 400 watt rating is for the speaker SYSTEM, not for each speaker. The two input connectors on the cab are wired in parallel -- the second connector enables you to connect a second speaker system in parallel if your amp does not have two (parallel) output connectors.

The 500 watt rating for the amp IS an RMS power rating and I suspect the 400 watt rating for the cab may not be. I'm with @Wasnex -- return the 4Ω cab and get the 8Ω version.
 
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#5
I am an experienced user in these
matters, and I agree with everything
that’s been said.
The 4 ohm cabinet will not give you
significant volume over the 8 ohm
cabinet.
You should exchange the 4 ohm now
for the 8 ohm cabinet. If you
decide in the future that you need
significantly more volume, adding
another 8 ohm cabinet will get you
there.
I see nothing on-line that indicates
that this head will drive any load
less than 4 ohm total. Two 8 ohm
parallel cabinets will give you
that 4 ohms.
 
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#6
Podgorny said:
The 4Ω cab is the correct one to use. The rating for the amp is likely 500W peak, while the cab is RMS, so it can handle much higher peaks. And in general, there's nothing wrong with a power mismatch, so long as you aren't driving things into distortion. And that's true for underpowered amps as well as overpowered ones.
Click to expand...
Not true, the amp is 500 watts RMS and the peak value of 500 watts RMs is 1000 watts peak.

Many cabinets can’t even handle their rated RMS mechanically below 50-60 Hz, which is why overpowering is more risky to the speaker.
 
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#10
bass player 53 said:
If you
decide in the future that you need
significantly more volume, adding
another 8 ohm cabinet will get you
there.
Click to expand...
To help make a more informed decision:
  • The speakers are rated 400W RMS
  • I believe the sensitivity for the cabs is 101dB 1W/1m
  • The amp is rated 300W at 8 ohms and 500W at 4 ohms

Calculated SPL of different amp/cab combos:
  • One 8 ohm cab at 300W = 125.8dB
  • One 4 ohm cab at 400W = 127dB
    • (1.2dB louder than one 8 ohm cab)
  • Two (matching) 8 ohm cabs at 500W = 131dB
    • (4dB louder than one 4 ohm cab)
    • (5.2dB louder than one 8 ohm cab)

The SPL figures may be a bit optimistic, but the decibel differences between each choice should be fairly close.
 
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#11
Hey All - thanks for all the replies. The 300w available @ 8 ohm for the Little Mark, and the 8 ohm cab version was the plan (in case I wanted to add another 8 ohm cab later). However, for those interested - I went back and took a look at Markbass' site and reviewed the specs. They actually do list the cab as 400W RMS and the amp as 500w "MPT", which is just marketing jargon it seems. I think when I quickly looked before my mind replaced "MPT" with RMS by accident...

In this case, I guess its safe either way? Just depends on whether or not I want the expansion capacity later. I guess I'd need to confirm if the amp is rated Max.
 
#13
seand123 said:
Hey All - thanks for all the replies. The 300w available @ 8 ohm for the Little Mark, and the 8 ohm cab version was the plan (in case I wanted to add another 8 ohm cab later). However, for those interested - I went back and took a look at Markbass' site and reviewed the specs. They actually do list the cab as 400W RMS and the amp as 500w "MPT", which is just marketing jargon it seems. I think when I quickly looked before my mind replaced "MPT" with RMS by accident...

In this case, I guess its safe either way? Just depends on whether or not I want the expansion capacity later. I guess I'd need to confirm if the amp is rated Max.
Click to expand...
No, no, no!

MPT just describes “MarkBass Proprietary Technology” which has nothing to do with rated power.

MarkBass is clear in their rated power as being RMS in all materials I have seen.
 
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#16
bass player 53 said:
I am an experienced user in these
matters, and I agree with everything
that’s been said.
The 4 ohm cabinet will not give you
significant volume over the 8 ohm
cabinet.
You should exchange the 4 ohm now
for the 8 ohm cabinet. If you
decide in the future that you need
significantly more volume, adding
another 8 ohm cabinet will get you
there.
I see nothing on-line that indicates
that this head will drive any load
less than 4 ohm total. Two 8 ohm
parallel cabinets will give you
that 4 ohms.
Click to expand...

Great advice as well.
 
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#18
@Wasnex already gave an exhausting answer in his first reply, but let me elaborate:

If the amp is stronger than the cab, you can blow it. That's the easy part.
Furthermore, as @agedhorse already hinted at, the power rating of a cabinet often refers to the thermal rating of the voice coil - the point where it can take damage (melt) by too many watts passing through, and the mechanical limit of the speaker almost always is less than that, meaning you threaten to literally rip the speaker by overexcursion before you melt the voice coil.
These are the dangers you're facing.
When do they become relevant? As @Wasnex already said, when you're playing in a loud environment, at volume levels that require you to drive your gear hard. When you're playing cocktail jazz with that gear, you'll probably never even come close to risking anything. When you're facing a hard hitting drummer in a loud rock band, the chances that a 210 will not cut it are much more real.
When you turn up the amp in a controlled environment, you will hear stress signals from the speakers (farting out), and when you apply common sense, you'll immediately abandon what you're doing and dial back on the volume or bass knob to lessen the load you're putting on the speakers.
In a super loud environment, those stress signals are less audible and you might miss them.
There is no real world scenario where you can safely predict how many watts an amp is putting out by the knob positions alone - you would need to measure the output to find a reliable number.

So, to sum it up and reach the same conclusion as most people here:
1. You can safely operate that system as long as you find yourself in the situation where an amp like that is more than enough and you have headroom to spare.
2. It generally is better to use an 8 ohm cabinet, should you decide to buy another one in the future, the 4 ohm version prohibits that and is not that much louder than a single 8 ohm.
3. If you can see yourself using that amp in loud environments, play it safe and get the 8 ohm cab.
 
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#19
I own a Little Mark head and two 210 cabs (same kind, but not XL).
as already mentioned, the head outputs 300W RMS at 8 ohms, 500W RMS at 4 ohms.

one 210 cab in 8 ohms is a nice pairing for that 500W head, as well as two 210s 8 ohms each.

I'd consider keeping the 4 ohms only if I had a Nano Mark instead (300W at 4 ohms) and was sure, I wouldn't need a second cab ever.
 
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