Yo Stocktony! I'll tell you, when you are sweating a purchase, I can feel your brain working 2000 miles away! Anyway, here's what the C-4's do that the 603's don't:
1. Generally sound better on any source, from overheads to harp. They have lower self noise, respond better to fast transients (sudden changes in volume), and are more accurate to my ears. *All of this is my opinion, not a fact*.
2. Bass rolloff, also known as a high pass filter, is useful in reducing "boom" when close mic'ing acoustic. Nice point- if you don't like it, turn it off. On some songs and some instruments, you want to let the bass come out more.
3. Pads are useful when close mic'ing cabs or percussion. When using a C-4 as an overhead, I usually don't use the pad, but that depends on the kit, the drummer, and how close the mics are to the kit.
4. Omni capsules, unlike all directional capsules (cardioid, figure of 8, wide cardioid, hypercardioid, etc.) produce virtually no proximity effect. In other words, they don't boost bass when the source is very close to them. Omnis, however, are a 2 edged sword, as they will pick up more room reflections, ambient noise, breathing, etc. Omnis are really cool with a great player in a great room, and not so good on a heavy breather in a bad bedroom. The additional capsules simply give you other choices.
In conclusion, it is my opinion, totally subjective and based on actual use, not scientific analysis, that the C-4's are better mics than the 603's, with or without the pad, the bass rolloff, and the omni capsules. However, it is also necessary for me to say that the 603's are very good mics, quite reasonably priced, and are very good on
acoustic guitar in particular. Whether the C-4's are really better mics, and whether they are worth the extra money, is a matter of opinion, and if anybody tries to say that one or the other is a fact, they are bullshitting you, or they are confused.
