The Sennheiser CX 300 which if i am right is the first set of IEMs from Sennheiser. Being a fanboy of Sennheiser i rushed to pick this one up and i must they’ve done a pretty good job. The CX 300 has a freq. response of 18-21,000Hz, Max spl 112dB got enough ‘oomph’ to make you get a good in-ear experience.I found that the mid and highs were pretty good, as with all sennheisers. The package comes from prices ranging from 35€ to 70€ (do an amazon search) which makes this well worth for its money.I still have one grouse with the CX 300 which is it feels kind of awkward in the ear, because the slightest tug tends to displace the headphones. Remember the in ear seal gives the headphones its awesome Bass effect and the sound isolation – with such a weakness, the CX 300 does disappoint me a little. But it might also be that since this is my first pair of IEMs may be i am doing something wrong!!? But i would definitely recommend the CX 300 for any aspiring IEM enthusiast!