is it a hiss or is it a hum? these are very different things.
hypertonic was 100% correct. the sm58 and sm57 micrphone capsules are exactly the same, the only difference in the two mics is the shape of the body and the popshield. except for the whole 58 is a stage mic etc. everymic is a stage or studio mic, they are what the are and you can use them how you please.
Your hiss may just be speaker hiss which is slightly accentuated by the mic hiss, it may not be as bad as you think. have you tried playing you stuff back on different speaker systems.
what software are you using? software can be noisy.
if you have any behringer gear in your signal chain that won't help either, some of their gear is usuable for for recording but alot isnt.
usb microphones can be very noisy too and i understand your budget considerations, but in my experience saving that little bit longer for the better gear is very very well worth the wait and you don't end up buying the cheap thing twice.
the usb microphones can be noisy because they have to fit the analog to digital converter inside of the microphone as well as all of the regular microphone circuitry.
a little known brand of microphones mostly because they are russian are octava. they make some great microphones and the housings are beautifully machined and they are generally solid mics. ive recently been out far northern australia recording wildlife with a combination of sennheiser and octava mircophones. octava do a usb mic too
http://recordinghacks.com/microphones/Oktava/MK-012-USB
i would tend to stick away from the likes of behringer, samson etc but if you are in a hurry to record then there is no harm in buying these microphones.
people will always tell you to buy the best and i am one of those people too but with budgets in mind, maybe extend your $100 to $150-200 dollars.
your computer maybe part of the reason for the noise too. depending on where the usb is running on the circuit board in relation to the other things such as fan, power etc this is get inductive noise from the board. so it isn't necessarily the quality of the mic you are currently using.
when all else fails go for the known brands even if they are a little more expensive and in some cases not so expensive.
http://www.bhphotovideo.com/c/produc...Condenser.html
http://www.bhphotovideo.com/c/produc...ro phone.html
http://www.bhphotovideo.com/c/produc...icrophone.html
http://www.bhphotovideo.com/c/produc...2u_XLR_to.html
http://www.bhphotovideo.com/c/produc...2u_XLR_to.html
if you have any questions feel free to message me and ill try my best to answer within your budget.
good to see some of the old boys are still here
yes im talking about you glice and #$%&^%$#