I have a semi-beginner playing on a brand new baritone saxophone. We have some jazz band pieces that require him to play D's and below. I've tried everything from having him not to bite down hard (if at all) to putting more air into the horn. I'll even have him go down a scale and he can play the notes that way.

Does anyone out there have any pointers on how to help my student play these notes? The problem once he gets these notes out will be to play them soft because we have one piece "summertime" he's supposed to play a lot of D's and some Bb's as well. Most of the time he'll jump the octave and play that note but not on purpose. I'm a trumpet player so i'm stuck. Can anyone help? Thanks!

Have you told him to drop his jaw? That's key to keeping low notes in their lower octave on bari.
If he's done that, it's (and I know that everyone says this) a leak. You say it's a brand new saxophone? Probably needs a bit of adjusting.

You don't move your jaw, tell him to open his throat.

Heh.. thanks for correcting my mistake. I am an alto player most of the time... Thanks!

Have you tried to play it on his horn? I could be one or multiple leaks.

Thanks for the comments everyone. I've heard it might be a leak from a lot of people. When we come back from spring break I'm going to test it out. I'm also going to tell him he needs to PRACTICE MORE. I'll assume it was like trumpet for me...I couldn't play all the way down the range of the instrument when I first started. It took practice to play low! Thanks again.

Like everyone else says, just drop the jaw, open the throat, and pray.
Most importantly, get him to practice, practice, practice!
I played clarinet for 4 years, and my teacher put me on bari sax. That was a huge jump!
I would suggest starting him on alto or tenor sax. Once he knows how to play low notes on those, put him on baritone.
Even the jump from tenor sax to bari can be difficult.

Again, DON'T move your jaw. Open your throat, that will take care of it if the horn is working properly.

A good reed may help to. For bari, a plastic reed works wonders and you don't have to worry about wetting it. I played cane on bari for a few years before a professor suggested I switch to plastic. Instantly, I was sounding much better.

<Added>

*too, sorry.

When i have a problem reaching a note, i think low. i can't really explain it, but i think of a LOW note, and i can usually hit it.

I was also told that think that you are trying to swallow a whole raw egg with out breaking it...i also tried to not imagine the taste...YUCK

I am a baritone saxaphone player myself and I have been taught to get low notes by using my throat and it does take some time to get used to playing below the D

From my personal experience, a player not being able to hit the lower notes was because the reed wasn't wet enough. This is a common problem with players who go from alto or tenor down to bari. There is a lot more reed there that needs wetting than what the player is used to. I couldn't imagine a plastic reed being used unless it's in a jazz setting.

After reading many other people's replys, I was thinking. What mouthpiece is the student using? Is is a stock, no name mouthpiece? I had huge problems with the stock mouthpiece on my school's bari so I got a mouthpiece that worked well for me on tenor, the selmer c*. That was an ok mouthpiece, but i still had some problems so i got a Beechler level 4 metal mouthpiece for like $125 from www.wwbw.com. They have a bunch more to order from than they state online and you can have them send you a couple mouthpieces, pick the one you like and send the other ones back. Then depending on they style of the mouthpiece the reed is going to be the next issue. On the c* i need to use at least a 3 for the reed, but on the Beechler, if i use a reed higher than 2.5 i can't play very well. If you can get your student to try different mouthpieces, it might help.

try a weaker reed strength and tell him/her to put some air in that horn. he/she will know when its too loud.