Monster has quite a few unreleased headphones under its belt that were kept under wraps for months until now. We managed to discover two unreleased and unannounced headphones that are said to see the light of day this year. Last time is was the Beats Executive headphones, and now Diamond Tears and Tranquility headphones. Apparently Monster has collaborated with JYP Entertainment, a popular Asian pop record label to introduce a pair of noise-cancelling on-ear headphones called Diamond Tears. These are as over the top styled as Monster's Tron headphones with a unique, jewelry-like clear crystal design with tangle-free cable, foldable ear cup design and are said to have super accurate and detailed sound reproduction.

Next up is Monster's titanium colored Tranquility headphones that have an over-ear design and described to have superior audiophile sound quality. The Tranquility headphones feature sound-isolating ear cups, dual input and output plugs, external active noise-cancellation with a built-in rechargeable battery and a fold flat to fit inside the included carrying case. Obviously we don't have an official release date, but we do know that the Diamond Tears headphones are expected to be sold at $250 while the Tranquility headphones will sell for $400.

Out of all the headphones announced back at CES 2011, the most awesome looking pair of carbon fiber infused over-the-ear headphones were slashed by Sleek Audio today. The Sleek By 50 Cents headphones looked very promising coming from a reputable audio company such as Sleek Audio. The wireless hybrid, $400 pair of headphones is no more says Sleek Audio as they cancel the deal between them and rapper 50 Cent. It's not clear what really happened, but Sleek Audio has released a statement regarding their actions:

Palmetto, Fl. XX, 2011 – Sleek Audio today announced the termination of the Brand License Agreement between Sleek Audio LLC (“Sleek”) and G-Unit Brands, Inc. (“G-Unit”), 50 Cent’s licensing company. In addition, the Brand License Agreement, including video production, between TV Goods, Inc, Sleek and G-Unit has also been terminated.

“We will be re-evaluating our Wireless Hybrid over-the-ear headphones at a later date. Currently we are working to bring our new, U.S.-made in-ear products to the market,” said Mark Krywko, CEO of Sleek Audio.

The official Sleek By 50 product website no longer exists.