I'm not sure about your specific problem with audio, but I do know that you can use software like DVD Shrink to fit your video onto a single DVD disc.
VHS to DVD conversion
I just got a capture card (Neo DVD standard).I have a couple of questions:
My volume controls are all the way up,I can see the video and hear it from my PC but when it is transferred to DVD,I don't get the audio.Why is this?I am using an Audigy sound card.I have the VHS video out to the input of the capture card and am using the audio out of the VHS to the audio line in on the Audigy.Also it only records part of the movie saying I don't have enough space on the DVD??Do I have to manually compress the video and if so,how?Thank you email@example.com