[retskrad]

Examples being the HD650/HD600, and the DT880/DT990. They share the same driver, but had different bass/mids/lows. How do the manufacturers tune the sound to a certain signature?

 

[PurpleAngel]

  Examples being the HD650/HD600, and the DT880/DT990. They share the same driver, but had different bass/mids/lows. How do the manufacturers tune the sound to a certain signature?

 
I would assume the design of the cups can effect the sound.

 

[Head Injury]

   
I would assume the design of the cups can effect the sound.

Basically. Different materials, cups, grills, pads, and damping of the driver itself result in changes to the frequency response and decay. The sound waves from the driver don't go directly into the ear, they reflect off everything in the cup. As they bounce around some will get amplified, or canceled out, depending on the acoustic properties of the housing. Just take a look at all the mods for the T50RP driver, including the well known Mr. Speakers headphones. It's amazing what a new cup can do: Before and After
 
Think of it as room treatment for headphones. It follows similar principles.

 

[retskrad]

Why does changing pads for example tame the treble, or increase the bass? Whats the science behind it?

 

[jodgey4]

Sometimes angled pads can push the more directional high frequencies away from or towards your ears, also changing what reflections occur against your outer ear. Bass can change due to seal and stiffness by helping direct the bass better towards your ear and not out.