made some minor change

If that's a 48 inch driver then the path is probably long enough.

You should realistically be looking for path lengths around 10 - 20 feet, depending on what you are trying to do. If you don't define any goals and post pictures with no dimensions or known parts you are probably going to take the long road to whatever your destination may be.

Your drawing is starting to look like a Labhorn. Look up Labhorn for a real world example of this type of horn with tons of available info. Just a few more folds and you'll be there.
Edited by diy speaker guy - 10/9/12 at 8:57am

Or just go with a proven design: http://billfitzmaurice.net/T30.html

Spiral it around the enclosure once or more.

It's hard to know how they will perform without modeling them. You can't model them if you don't know what driver is in there (unless you just want to use your own driver.)

It doesn't look like it goes very low and it probably doesn't need that vent.

You STILL have not stated any goals, all you are doing is posing pics and asking if the design is good. You need to spend more time with Hornresp and all these questions will answer themselves.

Have you looked up the Labhorn or the T30 as recommended for educational purposes?