Am I doing something wrong? Advice needed please.

[derrenleepoole]

I'm running the Mark Bass Little Mark 250 head into a 4 ohm Schroeder 12" regular cab, and I've noticed what seems like distortion on the low end, especially when pushing the volume. It's best described as a slight farting noise, not super noticeable, but now I have noticed it I can't stop listening for it!

I play a P-bass lyte with an active eq, and like most MB users hardly touch the eq at all on the head, using instead the 2 filters to shape my sound. But even then these never go past 12 o'clock, the same with the volume actually as I'm a quiet player.

I bought the 4 ohm version of the Schroeder cab so I could get the most out of my small MB head with little financial outlay, with a view to eventually getting an LMII that could still run at 4 ohms and have a cab that could handle it. But I'm wondering if perhaps I judged wrong?

Only 2 weeks ago I managed to blow a speakon cable (thought it was the cab at first) so you can imagine my relief when it wasn't. I know this isn't normal, and suspect something is a miss but I don't know what. So I need some thoughts on what it might be from some people in the know. Are there different types of Speakon cable and connections? I bought the Schroeder based on glowing praise on these forums, and so far I've been really happy with my purchase. But I'm now a little worried, because if something is wrong I can't afford to return it back to the US to replace. (I doubt it's that serious, but you know what I mean?)

 

[KJung]

Don't know if something is actually wrong here. While the 1210 is quite efficient (loud per watt within it's basic voicing), many pump 500 to 800 watts into that particular cab to get the best result (i.e., to open up the low end of that low mid voiced, high -3db rolloff cab).

My guess is, you are just running out of headroom. If you are cranking that VPF filter to levels approaching 12 o'clock, that pumps a HUGE amount of deep low end of of that head. Deep low end is what really eats up power (and is where you really hear the difference between 250 watts and 500 watts (all other things being equal).

So, if the 'farting' sound you hear only happens at your loudest playing level with the lowest notes of your bass, then it's probably just an issue of headroom, and an LMII (which just CRANKS through the smaller Shcroeders IMO) will easily fix.

Usually, if you have a problem with a driver, you will hear distortion, etc. at all volume levels and across most of the range of the instrument.

Just guessing hear, but I think you might just eventually need some additional wattage.

Edit: The only way to really find out where the issue is would be to try your cab with a different (more powerful) head, and try your head with a different 4ohm cab. That would help you isolate whether the issue involves the cab, the head, or if it is, as I suspect, just trying to push too much volume and low end out of a 250 watt head.

Edit2: If you are using the Mini 12 (I don't know why I assumed the 1210), then my guess is, you are just asking too much of a small 112 cab. Any 112 cab will start to fart out a bit when you really roll the low end into it. IME.