S.Coups/Seungcheol:When it comes to moans/whimpers/etc, S.Coups would actually be fairly quiet. He'd more of a giver than a taker, and when he is receiving, he is more just heavy breaths and the very occasional deep groan. He saves that groan for when he's coming, probably with your name, and if you can get him to make noise otherwise it's a huge accomplishment. That and he's also a big dirty talker. I mean, he's got a gorgeous deep voice and he just loves the way you react to it and he would just dirty talk even if it was for himself.
Jeonghan:He just makes the absolute best sex noises. I've read some fics about the boys singing during and actually whatever noises he made would be so beautiful sounding that you might mistake them for song. Like he's just so perfect that this would bleed into every aspect of life. Even when he's getting head and there's right or wrong way to do that, he was just look so gorgeous and sound ten thousand times better. And the sound of your name being moaned off his lips would actually almost kill you because it sounds so good.
Joshua/Jisoo:Just imagine being on your knees in front of him and you're giving him so much pleasure it's almost painful and he's just on the verge of cumming when his mouth hangs open and his voice cracks when he lets out a heavy "Jesus Christ". I love the irony and it actually really suits him (and now I just can't get that out of my head). He has such a sweet, small voice that hearing him mutter filthy things ("you like that, babygirl?" or "God, you look so good on my cock.") would be a contrast that you would never get over. And hearing him swear over and over in that sweet voice - it would wreck you. (Cause just the thought wrecks me but that's off topic.)
Jun:He would also be another quiet one. He's so concentrated on you and not blowing his load early that he gets pretty quiet during sex. And he's so athletic (with all the dance and the martial arts) that it would take a lot to getting him panting or breathing heavily. But this doesn't really bother you much.
Hoshi/Soonyoung:This kid won't shut up during sex. We all know he's like sex wrapped up in a cheesy sweatband and sex would be all or nothing with him and it's never nothing. So he groans, moans, whimpers, panting, huffing; any imaginable or unimaginable human noise to make during sex will come out of his mouth. He gets so into the head space of sex and really lets himself get lost in you that he never ever holds himself back vocally.
Wonwoo:I find him so hard to peg. He could either be very quiet or surprise you and burst out the worst/best kind of dirty talk you've ever heard and have the moans of a porn star. He would probably feel like his moans need to be a show for you, so he might exaggerate them a little. That's not even a bad thing. He wants to let you know you're doing a good job and turning him on and he can do that with his dirty words and dirty, dirty sounds.
Woozi/Jihoon:Whimpers; he has those shaky little whimpers, especially because he desperately tries to hold himself back. He can be kind of a grump and he's got this well-established thing about pride, but when that first, tiny little whimper escapes him you know you've broken him. Then they slowly get louder and more intense and some of them even become high pitched moans, all mixed in with gusting breaths. During sex he breaths like someone who's trying not to sound out of breath; and it's actually incredibly sexy.
DK/Seokmin:Loves to bit his lip and kiss you to mask his noises. He indulges himself much more in your moans and prefers not to have the attention on himself. If anything he lets out that epic, finishing moan when he's orgasming and it cracks his voice and shudders in the best way.
Mingyu:This motherfucker is a groaner. He groans full and deep and lets it rumble through his chest so you can see it and feel it and hear it so clear and just let it fuck you up. He doesn't shy away from making noise, and it's deep and manly and always serves to turn you on.