Hello,
Is it possible/safe to plug the head/rack internal power amp into an 8 Ohm 150 W cabinet? Specifically, into a Marshall MX212A, which is equiped with two Celestion Seventy-80 (80W 16Ω) speakers ...
Thanks in advance !!
Hello,
Is it possible/safe to plug the head/rack internal power amp into an 8 Ohm 150 W cabinet? Specifically, into a Marshall MX212A, which is equiped with two Celestion Seventy-80 (80W 16Ω) speakers ...
Thanks in advance !!
Yes it is safe to use this as long as you don’t run the power amp too hard. There is a wattage meter on the output page which will let you see how hard you are pushing the speakers.
QuoteDisplay More Wattage Meter
The internal power amp is mono, and delivers 600 watts at 8 ohms — however, the wattage will be lowered to 300 watts when used at 16 ohms. At 4 ohms, the wattage is electronically limited to 600 watts. If these 600 watts are exceeded, the power amp is deactivated for a moment, which will result in a short dropout. It would require insane volumes for such dropouts to occur — however, if you are connecting a 4-ohms cabinet, you should test it carefully to ensure that your loudest signals stay below that critical level.
The power amplifier provides sufficient headroom to avoid clipping, even with dynamic clean sounds. Very loud signals and transients will then be compressed by a soft-clipping circuit with a nice, organic sound.
If you are afraid of damaging your speakers with the built-in 600 watts power amp, then use the Wattage Meter to monitor exactly how much power is being delivered.
A speaker doesn’t get damaged by too much peak level, but by accumulating too much heat over time. Think of a traditional light bulb: When you switch it on, it takes a moment to reach full brightness. When you switch it off, it will dim slowly even though the current is cut immediately. Due to this time lag, it takes one or two seconds of overpowering a light bulb before it breaks. The same applies to the coils of your speakers.
The Wattage Meter takes account of this time lag and simulates the accumulated heat in your voice coil measured in watts. It is a unique tool that allows you to get a feel for the kind of volume you should expect for a given number of watts. You might be surprised just how loud a few watts can be!
A few rules of thumb:
• The maximum wattage of the power amp is not a measure of permanent load on your speaker coils. It depends on how loud you play. A 600 hp car will not use more horsepower than a 100 hp car while you cruise through town — more likely, it will be about 15 hp.
• Bass frequencies will put much more load on your speakers than high frequencies. Palm mutes create lots of bass.
• Cabinets with an open back will acoustically reduce the bass frequencies — this means wattage which the power
amp delivers, and the speakers still have to process, but you cannot hear it and therefore won’t realize.
• The scale of the Wattage Meter is calibrated to 4 ohms. If your cabinet has an impedance of 8 ohms, you need to
halve the displayed values. If your cabinet has an impedance of 16 ohms, you need to divide the displayed values by
4.
• If you combine multiple speakers, the wattage is split. For example, if you have four speakers each rated as 50
watts, they can handle 200 watts in total.
• If you are running at high volumes and notice any indications of speaker distress, turn down (Monitor Output)
Volume or Power Amp Boost.
WARNING!
Never connect an active device to the power amp output! Any active devices (such as power soaks) that
have a grounded circuit will destroy the power amp by creating a short circuit. Only passive speaker systems should be connected to the SPEAKER OUTPUT.
Please refrain from connecting devices with impedances lower than 4 ohms, as the power amp could be damaged.
Always ensure adequate ventilation - especially if mounting your PROFILER into a rack. Failure to do so may cause the power amp to shut down to prevent overheating.
Great !! Thanks a lot !!