Replaced a Panasonic V65 VT60 Series 65" 1080p plasma hdtv that still functions flawlessly but the OLED consumes a fraction of the electricity, will eventually pay for itself through significantly reduced electric bills.

Class D 1,200 watt @ 4 ohm ultra quiet, very low distortion, powerful, dynamic, highly detailed amps with a silky smooth midrange and treble presentation that is never harsh or bright and creates a solid,stable, plalpable and enjoyable 3D sound stage illusion that is wide, deep, detailed, open and very convincing.

Fully balanced ss dual-mono preamp that is very neutral, accurate and detailed that has a high-end quality from top to bottom with just a touch of midrange and treble  sweetness, warmth and euphony and an exceptionally strong ability to create a solid, stable and believable sound stage illusion . Great match, just like high quality tube preamps and depending on an individual's overall system sound preference, with very neutral class D amps.

 Replaced a pair of 2.7QR speakers that were approaching 25 years old in my system.  Both models are high quality 3-way planar-dynamic dipole designs with large dipole bass sections and very good midrange performance.   However, there's absolutely no doubt in my mind that the true star of the show and the biggest difference maker between these 2 speakers is the truly spectacular true ribbon treble transducer in the 3.7is compared to the quasi-ribbon  treble section of the 2.7QRs (QR specifying quasi-ribbon.  The significant treble improvement in treble quality and detail provided by the true-ribbon transducer in my system  is truly transformative in its effects on my system's fidelity, realism and enjoyment.

I had my room evaluated by a GIK consultant and bought about $3,500 worth of room treatments that have now been custom installed: stacked pairs of Tri-Trap bass traps in all 4 corners, multiple 244 bass trap panels (2 with Panel Art covers)and multiple 242 absorption panels with Scatter Plates to add diffusion (2 also with Panel Art covers) and 3 Wavy Leaf pattern 4" thick decorative panels.  These are a combination of bass traps underneath for absorption of excess bass frequency energy and diffusion on the surface for scattering higher frequency sound waves.  Overall, the strategy for my room was a  balance of sound absorption and diffusion throughout the room with an emphasis on diffusion on the front and rear walls.  They've only been installed for a couple days so far but the most significant changes I've perceived are an increase in the depth and width and openness of the sound stage illusion along with an increase in details, realism and naturalness.

    I added the Lumin D2, along with a Synology 20 TB hard drive unit for storage and an iPad for a controller mainly for convenience but also for improved sound quality.  I have about 3K CDs and a few hundred hi-res music albums currently stored, ranging from FLAC to WAV file types and from 16bit/44.1KHz sampling rates and resolution up to DSD-wide sampling rates and resolution.  I may be fooling myself  that I can accurately discern between the various resolutions, but I don't care since they all sound excellent to me no matter the resolution.  All these source components are on connected to my wi-fi and communicate flawlessly with each other via the included Lumin software app that is very good.  Not as robust as my prior JRiver software but very similar in mega-data inclusion and GUI general look and operation.

     I consider this bass system the best single upgrade I've made to my system in the entire 45 years that I've been involved in this hobby and building systems.  It's a complete bass system, for $2,800, that consists of four relatively small passive subs, 12"x14.5"x28" and 44 pounds/each, that contain 10" long-throw aluminum drivers.  All 4 subs are powered by an included 1,000 watt class AB amp/control unit.  Each sub is 4 ohms and all are connected to the amp in series/parallel configuration.

     i upgraded my Panasonic 1080p hdtv to an LG OLED 4K hdtv, so I needed to upgrade my 1080p Oppo UDP-105 to the 4K UDP-205.