Some random browsing I found SRH1540 on Shure's website. They're close-backed and share the same design as the 1440/1840. The pads seem to be velour/fabric. Price and release date are still unknown.
Transducer Type: dynamic, neodymium magnet
Driver size: 40 mm
Sensitivity : 99 dB SPL/mW
Impedance: 46 Ω
Max. input power: 1000 mW
Frequency range: 5 Hz - 25 kHz
Net weight (without cable): 286 g
Cable length: 1.8 m
Type of cable: Dual-exit, detachable oxygen-free copper
Plug: Gold-plated 3.5 mm stereo mini jack
Hope they can be an upgrade to my DT250.
Edited by NicoCat - 10/17/13 at 8:16am