Convertible headphones – Spain's DHS-1 from Palma Audio are that [€2'195]. These dynamic circumaural designs with a 50mm dynamic driver of 26mm voice coil use Sapele wood cups with a golden-ratio perf pattern in the back. A matching aluminium cover rotates by 14° to either leave the holes exposed or hermetically sealed, allowing the user to change the loading between open-backed and sealed modes with a simple turn of the plate. Sensitivity is a high 107dB/1mW in open mode, 109dB in sealed. Impedance is 32Ω. Weight is 490g. Included accessories are cables with 3.5mm and 6.3mm terminations; and a hard carrying case. Purely on paper, this is a very clever idea. The obvious challenge is how to optimize both modes with the very same chamber. Palma's designers seem convinced that after three years of R&D, they've nailed it. They even secured a patent for it. Intrigued? I sure am.
