Which model of guitar did you get? G 310, G 400, etc.

Poplar wood is one of the "select" hard woods they use. It's a good wood for guitars, light and stable, but Ash gives a better resonance or tone. Mohogany is a real hard and heavy wood that gives sustain and thick resonance. This of coarse depends on what the player is looking for and what's being played.

There are several types of pickups, each have a different sound. The pickup may not sound the same on the same type of guitar made of a different type of wood. This is because the woods density tends to effect the sound of the strings and the amount of vibration the pickup "picks up" from the body. Try a different pickup and see if it,s to your liking. There not that hard to install.

: I am not sure what you mean by "which one did you get" , but the humbuckers are black, non adjustable. The guitar is ivory colored, black pickguard, 4 knobs, with a ebony colored fretboard, though the sides of the board look like mahogany. The guitar cost, on sale, $200, probably because the tone pot was bent slightly. The guy at the store said it was poplar, but he didn't sound completely sure. I'd guess from the overall sound it probably is poplar, since It sounds a bit similar to a Strat made of poplar, which I tried. I also saw Strats that were made of Ash, which sounded different than the poplar Strats.
: : Most Gibsons and Epiphones are mohogany necks and bodies. The bodies are sometimes swamp ash, for a lighter feel and somtimes they just use select hard wood. The pickups can vary though. Which one did you get?

: : : Does anybody know what kind of pickups the Gibson SG has? For that matter what kind are the Epiphones? I bought an Epiphone SG and the pickups are different than the Gibsons. Or at least the Gibson has covers. Mine are open. My guitar sounds great as is, just thought I might be able to improve the sound with a pickup change.

: I am not sure what you mean by "which one did yo
u get" , but the humbuckers are black, non adjustable. The guitar is ivory colored, black pickguard, 4 knobs, with a ebony colored fretboard, though the sides of the board look like mahogany. The guitar cost, on sale, $200, probably because the tone pot was bent slightly. The guy at the store said it was poplar, but he didn't sound completely sure. I'd guess from the overall sound it probably is poplar, since It sounds a bit similar to a Strat made of poplar, which I tried. I also saw Strats that were made of Ash, which sounded different than the poplar Strats.
: : Most Gibsons and Epiphones are mohogany necks and bodies. The bodies are sometimes swamp ash, for a lighter feel and somtimes they just use select hard wood. The pickups can vary though. Which one did you get?

: : : Does anybody know what kind of pickups the Gibson SG has? For that matter what kind are the Epiphones? I bought an Epiphone SG and the pickups are different than the Gibsons. Or at least the Gibson has covers. Mine are open. My guitar sounds great as is, just thought I might be able to improve the sound with a pickup change.

perhaps i can help a little with this.. different Epi SGs have different pickups and stuff.
also, gibson SGs have different pickups on them too, so it depends what the particular type is. on the bottom of the pickup it sometimes will have a number to identify it.
generally, the pickups without the chrome covers on (or gold) are usually not the "better" ones, but thats all a matter of taste anyhow. ive heard of someone who put the chrome covers on their pickups that had none, and they claim it affected the sound, make it warmer. I have no idea since i never tried to tinker with a pickup like that.

Some Gibson SGs have single coil pickups, or any sort of variety of Gibson pickups on them. Some Epi SGs have Gibson pickups.
one way to tell the Epi SGs apart:

the lower end SGs tend to have bolt-on necks. doesnt mean theyre "bad", just put together differently, and sound a little different. The "better" Epi SGs have the set-in necks, like their Gibson counterparts.
You could read up on this at one of the music sales sites, or even at Gibson's website. they show the various models they presently make in the Gibson and the Epiphone lines at the Gibson homepage.

Generally, the pickups with covers on are usually higher in price.
generally, the set-in necks are more expensive.
generally, ebony costs more than rosewood.
generally, the bigger or fancier cut inlays in the fingerboard make it worth more.
some have inlays on the headstock too, these are usually higher-end guitars. the others are just painted logos.
Some SGs have ebony fingerboards, some have rosewood.
a few SGs have 24 frets (their Deluxe), but most have 22 jumbo frets.
seems to be, more often than not, they have Grover tuners.
at stores they tell me the dark red stained red SGs are worth more for resale than the other colors. (its more popular color.)

Some SGs have tremelos (Vibratoes of various types and brands) on them, some don't.

the easiest way to tell a "higher end" model from Epiphone is the headstock.
if it has the big split diamond shaped type logo its usually a "better" guitar.
also if it has the little mother of pearl logo thing in the middle of the headstock, its probably their G400 Epi. (Gibsons have this same logo on them.)
their other models don't seem to have the logo there.
the G400 seems like it is pretty darn close to a Gibson SG from what I have seen. I never owned an Epi though.