I'm not sure why it would be different now you're on a converter box but it may be something to do with how the box handles the 'demuxing' of the mpeg signal.

My hitachi tv has an option to adjust the default sound level for a particular channel - you might want to see if your tv has the same option, if the levels are consistent it ought to solve your problem.

With cable tv like I have, the problem is poor quality control back at the company's main distribution outlet. There should be a 'master control' room that checks the levels of everything going out. I suspect it's something about your converter box, since it's a new issue.

Take a look at the manual or the internal menus if it has them, or the manufacturer's website and see if they offer any solutions, otherwise.

Thanks pjb. I've noticed its especially bad when I tape a show on my VCR. The TV volume is fine, but when I go to watch the tape its extremely loud, even though the volume for that station was fine right before I taped it.

My cable provider exhibits widely-varying volume levels between non HD and HD channels. Some of the HD channels are startlingly loud.
Casey

You can buy a volume control box. I've got the same problem and found a box at a major online electronics store. I'm sorry I don't recall the name. It's a 3 letter
name , I believe, which is commonly mentioned in forums.

It was 30.00.

When I wrote to our local station's chief engineer he said the network insisted that output levels be at a certain point while other networks required other levels. It's
so bad that I sometimes avoid stations if I find anything
even remotely interesting on an alternate channel. I
am using OTA signal not cable. But the network still is the one who sets the level to cable and
it's probably in the contract what audio levels must be maintained to the public if they
are to be allowed to broadcast.

Thanks gardurnit and Casey.