Sparky Mark

Probably the only sure way is to take the grill of the front of the combo, remove the speaker and see if the impedance is marked on the rear of it.

The SMX 300 watter is forced (fan) cooled.

Noisiest fan I've ever had was in my mid 90s Hartke AH3500. Never bothered me because that's all I was used to (and it's still going strong). Back then gear was big, heavy, noisy (mostly ugly too) and real men played bass; nowadays I'm not so sure. 😁

Fans can add audible noise if they run when you are playing at low practice levels; some are noisier than others and can be intrusive. Dust is also sucked into the amp by fans; I have 35 year old natural convection cooled Trace Elliot heads that are completely clean inside. Unless I was running a natural convection cooled head near to its max output in a warm environment for long periods I wouldn't be concerned.

This is how Markbass used to do it. I doubt it's changed.

I have a couple of neo single twelve cabs that are great when "almost as good" is good enough but for those special occasions I'm happy to make the extra effort. This particular TE combo and cab are the smaller 33cm deep versions and even I (nearly 58, 5'9", 11st 7lbs) can move them relatively easily. On the other hand, perhaps we should all quit public performances once we are too frail to move anything other than balsa wood instruments and ultra light gear? 😅

I agree but I'm wondering whether one mode of operation could reduce the longevity of the amplifier more than the other?

Thanks Andy. Do you think there would any difference in the longevity of a solid state amplifier used with the output control at max and volume set via the gain control verses one where the gain was set just below input clipping and volume set via the output contol?

The real problem is the ageing process. A lot of us are in our 50s and 60s and simply can't schlep the gear we threw about with ease in our earlier days. Even 9lb plus basses are a major issue for some of our arthritic backs and shoulders. I use a folding trolley to move my gear and if that's not possible I ask if someone can grab the other handle to help me out.

I wonder whether latest amplifiers are simply quieter because of design improvements rather than the power amp topology? By maxing the output stage you will also be maxing the amplifier's noise floor and any other externally generated effects (mains hum and appliance noise, radio interferances, etc.) affecting the preamp. In live situations it shouldn't be a problem but as this is the worst signal to noise ratio it might not be ideal for low level recording. It's a mode of operation that can be employed with valve amps to get that unique power valve break up that preamp valves just don't achieve, but I'd be interested to hear from one of our amplifier designers (i.e., Agedhorse) whether maxing the output stresses the solid state power amp more than using it in the more conventional way?

If your combo is designed to allow an extension cab to be connected it's most likely the internal speaker is 8 ohms. Connecting an 8 ohm extension cab in addition to the internal 8 ohm speaker will present the combo's amplifier with a 4 ohm load. If the internal speaker is 4 ohms you should not connect another speaker whatever it's impedance as this could cause the amplifier to overheat and burn out.

It's the same as this. Two outputs, one of which is used for the internal 8 ohm speaker.

I've finally found a matching cab for my 1215 combo and cannot wait to hear them live.

Acebassmusic understood the OP question and this video explains clearly how a speaker driver produces different frequencies simultaneously. Many thanks.

Thank you but my reason for asking was that as right handed I'd never come across a lefty Fender bass case before. I bought this on Basschat as I'm a bit of Fender fan and was looking for an aged case for my CS62 relic P. When it arrived it was evident it was for lefty P basses and prompted me to research its rarity. With shipping I was happy to pay about the same as a new righty deluxe G&G case, so not cheap but reasonable considering its scarcity. I put expensive cleaning materials and several hours labour into it to remove silver spray paint and black paint over that on both sides so it's not for sale at the moment, but who knows? Thanks again.

This what the class D power section looks like. Only needs a single heatsink due to the higher efficiency compared to the class AB.