Hey Im new here. Love the site. Has tons of info (almost too much) which is why im having a hard time finding an answer.

Can I get the same type of bass response from an in-ear headphone that I can from a closed ear headphone? Or is that just not possible?

See I was always fooled that the driver size meant better all around sound. I'm looking for some real accurate ones for the gym(noisy place to be) but Im also a musician so I would love to hear the instruments in my song clearly especially the bass. So any info would help. Thanks

Here's a quick response, because I'm sure you'll get a lot more . . .
In-ears will absolutely provide you the same range, and even articulation the higher you move up the chain; however, it's the impact you'll miss. It's the same problem with moving from speakers to headphones in that the impact of the bass restricts from the entire body to around your head. With in-ears, that moves even closer, from around your head to right into the ear canal, creating the sensation that it's in your head. Try some true IEM's sometime and I think you'll see what I mean.

Ironman pretty much hit it right on the nail. In-ears can offer quite a large amount of bass, but the difference is the lack of "feel" around your head and body that you would hear with speakers and bigger headphones.

However, you said: "I'm looking for some real accurate ones for the gym(noisy place to be) but Im also a musician so I would love to hear the instruments in my song clearly especially the bass."

Many IEMs are actually quite good at bass accuracy and they are especially good for gym use because they are very portable, isolate A LOT of outside sound, and stay in your ears easily when moving/working out.

My sister uses a pair of JVC marshmallows, which are really low end IEMS. They aren't the greatest headphones ever, but for $20, you can't really go wrong, and when I tried them out, they had some major bass.

Check out SF5 Pro. They have strong bass and I find that they are great for listening to rock music.