Features Impervious to humidity and temperature variations. No wood used in guitar-construction. No humidifier required. RainSong's most refined thin-body (OM) with a full-scale/14-fret neck for a comfortable yet loud instrument. 25.4" scale length, 14-frets clear of the body neck for full-sized playability and feel. Unidirectional carbon soundboard is RainSong's lightest, and, combined with all-carbon-fiber construction, the most responsive. Fishman Prefix+T electronics Description Product Description The Concert Series is all about Warm Tone. These are the lightest soundboards built by RainSong using unidirectional carbon. Unidirectional carbon mimics the tight grain of a fine spruce soundboard. Thus, it is not surprising that this line produces a warmer tone. How do you describe RainSong's JM? Three words: loud, loud, and loud. And if that's not enough, it's also loud. This is the largest body RainSong builds. The sheer size, combined with the attributes of Projection Tuned Layering make the JM one of the loudest acoustic guitars on the planet. This guitar is loud. We had to say it again. But the JM is not just about power. The narrow waist and some layering refinements specific to the Jumbo soundboard give the JM some real finger style grace. The guitar is strong, but impeccably balanced, with bass, mids and trebles distinct, clear and, dare we say it again, loud.