Magnetic coupling for stereo loudspeaker systems

A loudspeaker system comprising:

• a right main speaker having a right main positive terminal and a right main negative terminal;
• a right sub-speaker having a right sub positive terminal and right sub negative terminal;
• a left main speaker having a left main positive terminal and a left main negative terminal;
• a left sub-speaker having a left sub positive terminal and left sub negative terminal;
• a right plus input terminal;
• a right minus input terminal;
• a left plus input terminal;
• a left minus input terminal;
• a transformer comprising a first winding;
• a second winding, a magnetic coupling effectively between the first winding and the second winding, and a plurality of terminals including a first point, a second point, a third point and a fourth point;
• the first winding being electrically connected to the first point and the second point;
• the second winding being electrically connected to the third point and the fourth point;
• and
• the loudspeaker system being configured such that
• a) the right plus input terminal connects to both the right main positive terminal and the right sub positive terminal,
• b) the right minus input terminal connects to both the right main negative terminal and the second point of the transformer,
• c) the left plus input terminal connects to both the left main positive terminal and the left sub positive terminal,
• d) the left minus input terminal connects to both the left main negative terminal and the fourth point of the transformer,
• e) the right sub negative terminal connects to the first point of the transformer, and
• f) the left sub negative terminal connects to the third point of the transformer.

A loudspeaker system operable in relation to a ground, the loudspeaker system comprising:

• a right main speaker having a right main positive terminal and a right main negative terminal;
• a right sub-speaker having a right sub positive terminal and right sub negative terminal;
• a left main speaker having a left main positive terminal and a left main negative terminal;
• a left sub-speaker having a left sub positive terminal and left sub negative terminal;
• a transformer comprising a first winding, a second winding, and a magnetic coupling effectively between the first winding and the second winding;
• a first electrical path from the right main negative terminal to the ground;
• a second electrical path from the right sub negative terminal to the ground;
• a third electrical path from the left main negative terminal to the ground;
• and
• a fourth electrical path from the left sub negative terminal to the ground, the first electrical path being of lower impedance than the second electrical path at frequencies greater than 200 Hz, the third electrical path being of lower impedance than the fourth electrical path at frequencies greater than 200 Hz, the second electrical path passing through the first winding of the transformer, and the fourth electrical path passing through the second winding of the transformer.