Magnepan 3.7x

The Magnepan 3.7x is a full-range planar magnetic speaker designed to deliver exceptional sound quality and a unique listening experience. The 3.7  features a 1.25-inch-thick panel that measures 22 inches wide by 68 inches tall, with a thin-film planar magnetic driver.

The 3.7x is known for its detailed, transparent sound with excellent imaging and soundstage. Its dipole design creates a spacious, natural sound free from the coloration and distortion often associated with traditional box speakers. The 3.7  also features a one-piece extruded aluminum frame that provides stability and eliminates the need for a separate stand.

The speaker requires a good deal of room space to perform at its best, and it is recommended to be placed at least 12 inches from the back wall and 4-5 feet from the side walls. The 3.7  is a popular choice for audiophiles and music lovers who want to experience the unique sound quality that Magnepan speakers are known for while being relatively affordable compared to Magnepan's higher-end models.

What is unique to the Magnepan 3.7x vs 3.7i

The general idea of the Magnepan X program is to take the existing design of a given speaker (a Magnepan i series speaker),  and, almost one-for-one, replace all of the components leading up to the driver with superior ones. These substitutions yield a noticeable, graphable, and awe-inspiring improvement. There are certain model-specific features, but the core X upgrades include the following:

Better Capacitors: All capacitors that aren't already, are replaced with high quality, copper-rich, polyproylene capacitors [banks]. Each capacitor [and bank] used is individually tested to the hundredth, so left and right crossovers' capacitances are within five thousandths. With the increased level of testing and tighter tolerance, minor value tweaks are employed in some models, resulting in fewer capacitors used and a smoother response overall. 

Better Coils (inductors).
All coils replaced with high-gauge copper wire, air-core, and bobbin-wound coils [arrays]. Each coil [array] used is individually tested to the tenth so that the inductances of the left and right crossovers are within five hundredths. 

Better Wiring:
Existing signal path wiring upgraded to 15-gauge or higher solid copper wire and trimmed to tighter specification. Higher level design, layout, and pathing of the crossover components such that wire lengths are short and the overall wire mass is considerably reduced. Left and right crossovers and nameplate impedances are ensured to be equivalent for ideal balance. 

Better Connections: All connections within the circuit, from the solder lug attached to the terminal screw on the nameplate, to the crossover board, to the driver terminal block, and back are soldered connections. Besides the terminal screw, solder lug, and jam nut connection on the nameplate, there are no mechanical connections used.

Better Inputs: All nameplate components are gold rather than nickel. 

Appearance:The appearance of an X Upgrade is not intended to be visually any different from that of its non-X counterpart (aside from the gold nameplate components in situations where that wouldn't already be gold). The cover of some models may be visible, such as with the MG 1.7x, and as such, that will be noticeably different in a side-by-side test, from the back of the speaker. The nameplate will also have a small X after the model to denote that it is part of the X Upgrade program.