I was so shocked and surprised that it took me a couple of moments before I even paid attention to the quality of the sound I was listening to. Just being able to hear without having to crank the volume was pleasure enough in itself for the first little while. Once I started to pay attention to what was going on inside my ears I was even happier. I had been a little leery of the PCS-150s advertised bass enhancement as I'm not a fan of bass heavy music. However all it means in this case is they've found a way to create a full, rich and balanced sound. There's none of the tinniness I've long come to associate with ear phones and neither have they resorted to most people's answer to that problem by simply amplifying the bottom end.
One of the tracks I use for testing headphones and speakers features a band that uses a lot of hand percussion alongside the standard rock and roll set up of guitars, bass and drum kit. Not only could you make out instruments the percussionist was playing normally lost on most speakers and ear buds, but you could also hear each instrument and the vocal harmonies clearly, distinctly and proportionate to their place in the mix. It was like the audio equivalent of 3-D as the sound had a depth of field you very rarely have the privilege of being able to appreciate. You could even hear the individual notes being played on the acoustic bass and the pitter patter of the congas drums, instruments which are normally lost when played in a rock and roll band.
To say I was impressed with the custom moulded eers PCS-150 ear buds isn't overstating it. Not only do they live up to their hype of providing a product that eliminates a high percentage of atmospheric noise common to the urban landscape which fits comfortably and securely into your ear, the quality of the sound they produce is as good as any high end speaker system if not better. While the PCS-150 comes complete with a built in microphone, for $30.00 less you can purchase the PCS-100 and get the same quality sound without the microphone. For the real audiophiles out there they also have the 200 series with even more enhancements to the sound quality for $299.00 with and $269.00 without the microphone. I doubt my ear is good enough to notice any difference, but if they are of the same quality as the 100 series, I'd bet they're worth the extra $100.00.