Question Low audio after render

Thank you for your help! i do have audacity (the program). but, that's another whole new learning experience. and, thank you for your service, sir. my late husband was navy. brother retired navy. father retired army (don't know what happened there...HAHA). Derek has been responding as well, so i better get on the stick. thanks again!!

thanks. downloading now. WOW! over an hour to download. the other files weren't that long, so i guess this one has a lot of things changing. i'll have to find out where i go to have these update automatically. haha guess it's tea time!
also, i rendered the small clip with what you gave me....i don't see a difference in the outputs, but i'll make sure i use those settings. so, this is what i'd use for ALL videos processed regardless of what device they are shown (some websites, some at big-screen venue).

so, this is what i'd use for ALL videos processed regardless of what device they are shown (some websites, some at big-screen venue)

Magix AVC is the main encoder in version 15 now - this is a new encoder which can take advantage of GPU Acceleration.
If you have an Nvidia graphics card, you can render using NVENC for faster render times.
If you have an AMD Radeon graphics card, you can render using VCE for faster render times.
If you have an Intel CPU with integrated graphics, you can render with Intel QuickSync.
If you have none of these options, you can still render with the CPU only.

All the above options are accessed by going into the Render As window I showed you, selecting an Output Template and then pressing the Customize Template button.
At the bottom of this window you will see Encode Modes.

Output for Film Festivals is a completely different "kettle of fish".
Film Festivals normally have very specific specifications/formats you must render with.
There is no simple answer to this until you cross that bridge.

If your audio sounds OK through your headphones, but sounds different through your computer's speakers, it sounds like your problem has nothing to do with Vegas.
Each computer will be set up differently for Audio - it can get very confusing to explain this, without seeing your computer first.

Generally speaking, right-click the speaker icon in lower right corner of your Windows Taskbar.
If you are using the latest build version for Windows 10, select Sounds on the right-click Menu.
Then select Playback.
See if this window changes when you connect your headphones.
Double-click Speakers and go into Controls and make sure levels are at 100%.

Also left-click speaker and make sure levels are at 100%.