Hi, I'm looking for a pair of budget tracking headphones and have a budget of up to £50. Ideally I would like something with a replaceable lead. I've done quite a bit of research and come up with the following models :- Monoprice 8323 - £15 Superlux HD669 - £24 Superlux HD661 - £24 Superlux HD631 DJ - £36 What are you thoughts on these headphones? Which would offer the best audio quality and prevent sound leakage into the microphone most efficiently? Are there any other headphones that have a replaceable lead that would be a better alternative? What would you recommend?