I am quite happy with the bass in my S4's. You can do good bass and descent mid/high with <$100 IEMs.
Are you referring to the Klipsch image s4? I'm looking for a fuller sounding IEM, but I haven't been able to find any. The cheap (on sale) Sennheiser's I bought a couple of months ago left a lot to be desired in the frequency response category (even on paper, my skull candy model had better specs for the same price, not on sale), so I'm hesitant to purchase any sub $100 models from this company.
Oh, and I don't want this post to be portrayed as me crapping on these phones, I don't have them. I had bought the much cheaper CX150's (I think I got them for $15), which had great reviews and lots who liked the bass response...but it wasn't the sound I was looking for. So please don't take this as me saying Sennheisers are bad, I just need more full sound personally. My CX150's sound crystal clear, just not full enough for me if that makes any sense. Then again, they are bargain bin, so I get what I pay for.