Modified Fostex T50RP orthodynamic/planar magnetic headphones. Introduction from MrSpeakers's website:
"We want your expectations to be unrealistic. And we hope we'll exceed them.
When we built the Mad Dog headphone, our goal was to deliver a sparkling, musical and immersively realistic listening experience at a price many people could afford, without breaking the bank. We believe the Mad Dog blew our goals away. The Mad Dog is a really fun headphone and we hope it will make you want to rediscover your music library, over and over.
Each headphone is hand modified and tuned to:
Be super-fast and ultra-revealing
Deliver exceptional channel balance with broad and spacious imaging
Increase bass extension, while keeping it tunefull and tight
The tech specs don't really mean much for headphones, but here are the not so gory details:
Frequency range from 16-22KHz
Impedance 50 ohms
MrSpeakers' Mad Dog headphones can be driven by most personal music players, including iPads, iPods, iPhones, laptops, PCs and other devices. It should be noted that we've come across some tier-2 brand phones and media players that really can't provide enough power to really drive this headphone adequately. To make the most of the Mad Dog headphones, MrSpeakers recommends the use of a good (or great) amplifier, DAC or DAC/Amp with at least 100mW per channel.
The great thing about these headphones is that the better the source components the better your headphones will sound."
The headphones had very good reception in the 2012 New York Spring Head-Fi Meet. It has been said by many who have heard both that the Mad Dog are a more neutral headphone than the Thunderpants, a popular T50RP mod.