You will need an amplifier. You're likely to need one anyway, if you're unsatisfied with your current results. Even the best headphones will not perform well driven by a weak, shitty amplifier.
This device hooks up like a speaker, but is a direct transducer. Mounted firmly to the bottom of your chair and driven with sufficient power, it can hammer your brain flat through your arse.
This device hooks up like a speaker, but is a direct transducer. Mounted firmly to the bottom of your chair and driven with sufficient power, it can hammer your brain flat through your arse.