Mbox 2 headphone quality bad?

[Eas Craven]

Hi. I'm primarily a mix engineer. At home I run Pro Tools 10 with an Mbox 3 Pro. I use some Mackie monitors and Audio Technica ATH-M50 headphones.

There's a rapper who pays me to run sessions at his house on his setup. He has an Mbox 2, some older Mackie monitors (I think the first MR5s), a Presonus preamp, Sterling Audio mic. I like to give him a rough mix to the two track before I leave; I do the final mix when we get the tracks from the producer.

His monitors are against the wall in the corner (untreated room) so I can't really trust what I hear. So I thought it would be a good idea to bring my headphones along since I really know them. I was surprised to find that when I plugged my headphones into his interface, the sound was terrible. It was very thin and processed sounding compared to my Mbox 3 Pro.

Now is this normal or is there something wrong with the Mbox 2?