The GMP 450 is the closed back cousin of the GMP 400, which has an open back design.   The sound is very similar to the open back GMP 400, but with a little more bass response and narrower soundstage.  Very impressive though for a closed back design.   Interestingly, I found that the GMP 450 requires a decent quality headphone amp (I had them hooked up to an Icon Audio HP8) to really make them sing, whereas the GMP 400 was more flexible about it's source.   The earcups are mounted on what German Maestro call a cardomatic suspension...

The German Maestro GMP 8.35 D (and it's higher impedance relation the German Maestro GMP 8.300 D) are without doubt the toughest headphones I have come across.  German Maestro call them "nearly indistructable" and I agree!   Sound quality is very nicely balanced.  Bass response is rich, with accurate and precise trebles.  The GMP 8.35 D and 8.300D are both serious audio monitoring tools that are refined and insightful. This is a reference quality headphone that is suitable for studio, home Hi-Fi or portable applications.  At a push you could...

The GMP 400 is handbuilt in Germany and comes with a 3 year warranty.  The GMP 400 is the open back cousin of the GMP 450, which has a closed back design.   The GMP 400's sound is very nicely balanced.  Enough warmth to make them an enjoyable listen, with an incisive precision that allows you to really hear all the hidden detail in a good quality recording.  I feel the balance is just right.   These headphones are like a mixture between all the things that are good about the Sennheiser HD650, the Grado SR325is and the Beyerdynamic DT880.  Not...