A note from Grain Audio's Designer on the OEHP .01.
In the consumer electronics market many products share similarities while being significantly different. The headphone market is a particularly trick field after all, all headphones have a headband and two earcups. When you get into the materials and details is where the the differences really stand out. The Grain Audio OEHP.01 is a proprietary design conceived of and designed by us. We stand by it as unique without reservation.
If you squint at the OEHP.01 and the TMA-1 there are similarities in the headband, earpad and method of wiring the earcups together. However none one of these details are unique to the TMA or the OEHP. The headband type can be found on many audio headphones in the market as well as safety headsets used in the construction and engineering field. Using an exposed cable to wire earcups together and provide adjustability is not a new feature either. This detail has been seen on audio and communications headphones for decades. The earpad style can also be seen in several other products.
All that being said the size, shape, material and execution of the "similar" components is drastically different between the OEHP and TMA. Our headband is an integrally colored glass reinforced ABS with a concealed adjustment track. It is not a rubber coated plastic with expressed registration. The headband has has been shaped and designed by us and built to our specifications. The PU earpad is a different durometer, shape and size compared to the TMA. We have designed it for superior acoustic isolation and it works with our earcup/driver design to deliver a balanced natural sound rather than a bass heavy profile.
Beyond these parts the hinge and adjustment mechanism is completely unique to Grain Audio. Other products use a fairly typical gimbaled hinge, our injection molded elastomer bushing with integrated vertical adjustment function is completely unique to Grain Audio. From sketch to hard tool this is a one of a kind part. The use of a solid wood earcup designed and engineered by Grain further distinguishes the product acoustically and aesthetically.
As stated before the OEHP.01 is a product unique to Grain Audio. It was designed in house and engineered with our own manufacturer to deliver great acoustic detail and a unique aesthetic and material experience.