An assembly, comprising: at least one output device comprising at least left and right speakers; at least one cord connecting the left and right speakers to a plug, the plug comprising: a) a conductive distal tip connector for receiving audio signals for play on a first one of the left and right speakers; b) proximal to the conductive distal tip connector, a first conductive ring for receiving audio signals for play on a second one of the left and right speakers, the first conductive ring being a continuous cylindrical ring; and c) proximal to the first conductive ring, first and second arcuate conductive segments (36, 38) having respective first and second ends (40, 42), the first end of the first arcuate conductive segment facing the first end of the second conductive segment and being spaced therefrom, the second end of the first arcuate conductive segment facing the second end of the second conductive segment and being spaced therefrom; and d) an extension port device electrically connectable to the first and second conductive segments and configured for electrically shorting the first and second conductive segments. at least one output device comprising at least left and right speakers; at least one cord connecting the left and right speakers to a plug, the plug comprising: a) a conductive distal tip connector for receiving audio signals for play on a first one of the left and right speakers; b) proximal to the conductive distal tip connector, a first conductive ring for receiving audio signals for play on a second one of the left and right speakers, the first conductive ring being a continuous cylindrical ring; and c) proximal to the first conductive ring, first and second arcuate conductive segments (36, 38) having respective first and second ends (40, 42), the first end of the first arcuate conductive segment facing the first end of the second conductive segment and being spaced therefrom, the second end of the first arcuate conductive segment facing the second end of the second conductive segment and being spaced therefrom; and d) an extension port device electrically connectable to the first and second conductive segments and configured for electrically shorting the first and second conductive segments. a) a conductive distal tip connector for receiving audio signals for play on a first one of the left and right speakers; b) proximal to the conductive distal tip connector, a first conductive ring for receiving audio signals for play on a second one of the left and right speakers, the first conductive ring being a continuous cylindrical ring; and c) proximal to the first conductive ring, first and second arcuate conductive segments (36, 38) having respective first and second ends (40, 42), the first end of the first arcuate conductive segment facing the first end of the second conductive segment and being spaced therefrom, the second end of the first arcuate conductive segment facing the second end of the second conductive segment and being spaced therefrom; and d) an extension port device electrically connectable to the first and second conductive segments and configured for electrically shorting the first and second conductive segments.