The shells of the PHX are 11-ply hybrid shells. The woods used are progressively harder from the center ply to the outer plies. The center ply is jatoba; this is a very hard wood' and it "anchors" the fundamental of the shell. Sandwiched on either side of this is kapur. This wood is in the mahogany family and adds warmth to the sound of the drum. The inner and outer plies are maple, except in the case of drums using the optional burled ash outer ply. These drums use an outer half-ply each of maple and burled ash. Maple rounds out the tone adding high and mid frequencies to the shell. Bearing edges
All drums have a 30° bearing edge, but each "family" of drums uses a different profile. Bass drums have a sharper edge cut toward the outer plies. This gives the bass drums attack and shortens the decay. Floor toms have a slightly rounded edge to give them a perfect balance of attack and sustain, making them very articulate at all dynamic levels. Toms have an even more rounded profile for warmth and sustain. This combination of shell composition and bearing edges makes PHX what many of our artists described as "the most musical drums [they] have ever played". Hardware
PHX uses redesigned versions of the Nouveau lug and YESS. The new lug mounts on a square hook rather than a round post. This keeps the tension rod in perfect vertical alignment and eliminates the need to use two hands while tuning the drum. We used the aluminum die-cast hoops made popular on our Absolute series for PHX. These hoops are very light but rigid, giving you the open, warm sound of a triple-flanged hoop and the accurate tuning of a die-cast hoop. Lugs and hoops are available in chrome or gold.
The new version of the YESS mounting system supports the drum at the top and bottom. The new version mounts the tom bracket onto a piece of the shell, and that wooden plate is isolated or shock-mounted using rubber grommets. A 3-piece fastening system is used to attach the new YESS to the shell, and the inside and outside fasteners do not touch. This system totally isolates the drum and allows the full tone to come through and maximizes sustain.
They are listed at the top of the web page so at least Yamaha is proud of them.
The biggest complaint I have heard and read is that they are so expensive. I've heard that a six piece set can cost you as much as $10,000. Way out of my league so I don't know what a bottom price would be if you pursued it.
A well know Yamaha and Zildjian endorser told me face to face just three weeks ago that he was well satisfied with his Yamaha Maple Custom drums, but Yamaha wanted him to use the PHX kits to get them more in the public eye. He said his PHX drums sound great, but so did the Maple Customs. I really wonder if he would have changed kits if it weren't for the push from Yamaha. I never played the PHX drums, the price being too far out of my league.