Design and features:The Marshmallow Wireless HA-FX39BT has an integrated microphone and volume, music player function, and call connect/disconnect controls for use with paired Bluetooth devices. This model uses a collar/earphone design - all of the electronics and controls are incorporated into an open collar that sits around the neck, and the earphones are attached to wires that extend from the collar. This model comes with two pairs of ear pieces in various sizes and a USB charging cable.
Sound quality: We found the Marshmallow Wireless HA-FX39BT delivers sound quality that falls in the good range - it reproduces music and voice reasonably well despite the obvious shortcomings in its sound. The overall sound can be summarized as boomy and somewhat hazy. Bass (as in bass drums, bass guitars, stand-up bass, etc.) good impact but is boomy, somewhat prominent, and deep bass is lacking. The midrange (voices, guitars, horns, etc.) is somewhat hazy, and a bit thin and grainy, and somewhat overwhelmed by the bass. The treble (cymbals, the upper range of violins, etc.) is fairly extended but a bit smeared (sounds that should have a delicate shimmer sound blurred). While the sound has a good sense of liveliness it is closed-in (sound-wise it is obvious that you have something plugging up your ears).
Comfort: As typical of in-ear models the Marshmallow Wireless FX39BT produces a sense of pressure in the ear canal opening that might be uncomfortable for some. It took a lot of fumbling with the earphones when inserting them to get a good ear canal seal, and if the ear canals are not sealed properly the sound quality is affected and the bass sounds subdued, or the overall sound level is reduced. The collar is not generally noticeable unless it interferes with clothing. When the earphones are taken out of the ears they can hang from the collar is very convenient; the collar has adjustable slides that limit how much the earphones will dangle and generally keeps them out of the way.
