What’s In The Cabinet?

Celestion G12M GreenbackWhat’s in an amp cabinet?   As it turns out, quite a lot.  In this video I do an experiment with the same two AC15 amps as in my last video– the AC15C1 Custom, and the AC15HW1 hand-wired.

Both amps use the same Celestion Greenback G12M speaker, and these two here have each been played about the same amount, so they should be “broken in” evenly.  

Now, by disconnecting the wires from the two speakers, and routing them through an AB box to the external speaker output of one the amps, I can isolate a single amplifier circuit, and hear it through both cabinets in turn.   In this way, we can first listen to the AC15C1 amp circuit through its own cabinet, and then listen to that same AC15C1 amp circuit through the AC15HW1 cabinet.   Switching back and forth really highlights the different sound character provided by the two cabinets.

VOX AC15 High Frequency DiffuserWhy so different?  The AC15HW1 cabinet is obviously larger, which provides a bigger resonant cavity.  It’s also built with birch plywood which is lighter weight and perhaps more resonant than the denser MDF used in the Custom.   Another important difference is the high frequency diffuser used in the AC15HW1 which really softens the high-end.  In the video, I also experiment taping a makeshift little diffuser over the AC15C1 cabinet to see what happens.