firmware (and audio problem)

Well I started with an audio problem and have gone throught the other messages in the forum to no avail.  Basically the sansa device just doesn’t playloud enough.  I set the EQ to max values and there is some increase, but still not particularly loud.  (and yes the volume is all the way up).  One of the repeated suggestions is to update the firmwar but I can’t seem to figure that out.  My version is 4.1.07a.  The updates available on the website specifcally say they do not work with version 4 firmware.  Not sure what to do from here.

You can update your Firmware. The message about not being for 4.xxx
firmware are for the update. You want to use the Sansa Updater.
Download and install the Sansa Updater. Then set your
player to MSC mode by going to Settings-USB. Plug your player
into your computer and it will update your firmware. I believe I also
had Version 4.1.07a.  I now have 4.1.08.

As for the volume. What files are you using?Type of headphones?
Speakers? Also I discovered that setting all the EQ bars on mine
on 0 ( flat) causes it to boost up in volume like a loudness button.
All must be exactly on 0 and set to Custom.  I only use this
myself when I am inputing to another sound device.

I forgot the link.

Click here for the Sansa Firmware Updater