Dvd audio quality

[tfamok]

Hi everyone. I hope you are keeping well.
I have been converting a few mkv & mp4 video files to DVD recently. I have noticed when playing the burned DVD’s on my DVD player that the sound is slightly mumbled/hard to make out sometimes when people are talking. I have bought a good quality soundbar with (clear voice) on it but this makes little difference. I have tried adjusting the tv audio setting also but because my original DVD’s are of perfect visual/audio quality when being played I’m guessing this is not the issue.

I have spent a long time researching this topic and to be quite honest, i find the whole business of digital audio way beyond my understanding. So, I thought I would seek help from a few intelligent audio experts. Despite my research I seem to have more questions than answers.
I tried converting the same video file with different audio formats to see if made a difference to the final output. I thought ac3 video would result in better output when being played on dvd than aac audio. This made no difference although maybe I’m going about it wrong.

So I guess my questions I would like help with are:
1. Does the DVD conversion/authoring software make a big difference? At the minute I am using ConvertXtoDVD 4.1.19.365 but am thinking of buying the latest version of wondershare video converter. Would this make a difference or am I wasting my money?
2. Would a video with ac3 audio and a video with aac audio give different results in quality when converting?

Thank you so much for your help people. This place is great. Being able to seek help from people with such a vast wealth of knowledge in this subject, for free, is outstanding. The internet is a wonderful place.
Thanks again, Teddy.

[hech54]

Never buy crap to try to improve crap.

[pandy]

It can be few problems so without detailed analysis it will be impossible to give you correct answer.
I would try to create custom audio track (custom volume settings).

[DB83]

Or to put it another way.

You can not get back what has been taken out in the original conversion to mkv/mp4. The people who make these (assuming that they have not come from official sources) often do not know or do not care about final quality. Their motives are elsewhere.

[sneaker]

1. Does the DVD conversion/authoring software make a big difference?
2. Would a video with ac3 audio and a video with aac audio give different results in quality when converting?

This is usually not a question of quality but of mixing. If the source audio has been down-mixed with a low center speaker (where most of the dialog happens) voices will be low. Needs higher center mixing coefficient. Or if the dynamic range is high with quiet voices. Then needs dynamic range compression ("night mode"). If mixing is too loud then clipping will happen, software needs to protect against it (normalization). And needs to use sufficient bitrate - but that's not noted by people.
If the software doesn't offer such options then yes: the DVD conversion software makes a difference.

[tfamok]

1. Does the DVD conversion/authoring software make a big difference?
2. Would a video with ac3 audio and a video with aac audio give different results in quality when converting?

This is usually not a question of quality but of mixing. If the source audio has been down-mixed with a low center speaker (where most of the dialog happens) voices will be low. Needs higher center mixing coefficient. Or if the dynamic range is high with quiet voices. Then needs dynamic range compression ("night mode"). If mixing is too loud then clipping will happen, software needs to protect against it (normalization). And needs to use sufficient bitrate - but that's not noted by people.
If the software doesn't offer such options then yes: the DVD conversion software makes a difference.

Sneaker, I'm not at all clued up with audio. Thought I was a little until looking into this subject. If I have a video that has audio, how would I go about finding out if the mixing is bad or normalization needs to be applied. Is this possible for a novice to do. Could you recommend any software to do this?

[tfamok]

Thank you for the feedback guys. Much appreciated.

[sneaker]

Sneaker, I'm not at all clued up with audio. Thought I was a little until looking into this subject. If I have a video that has audio, how would I go about finding out if the mixing is bad or normalization needs to be applied. Is this possible for a novice to do. Could you recommend any software to do this?

First step is to find out what exactly your problem is. You talked about "mumbled" and "hard to make out sometimes when people are talking". Not really sure what you mean by that.
1. The voices are always too quiet compared to the sound effects?
2. Both voices and sound effects are too quiet?
3. In some scenes audio is loud and clear and only in some scenes too quiet? (effects, voices or both?)
4. The audio is crackling or has other audible artifacts?
5. How many channels does your source audio have?
6. How many did it have originally?
7. How many does it have after you converted to DVD?
8. Is your source already too quiet? (effects, voices or both?)

[hello_hello]

I thought ac3 video would result in better output when being played on dvd than aac audio. This made no difference although maybe I’m going about it wrong.

AAC isn't a supported audio format for DVD. Can ConvertXToDVD convert the audio to AAC or am I misunderstanding what you wrote?

So I guess my questions I would like help with are:
1. Does the DVD conversion/authoring software make a big difference? At the minute I am using ConvertXtoDVD 4.1.19.365 but am thinking of buying the latest version of wondershare video converter. Would this make a difference or am I wasting my money?

Often the free equivalents of paid software are just as good or better, as is probably the case here. Give AVSToDVD a try.

2. Would a video with ac3 audio and a video with aac audio give different results in quality when converting?

I'd imagine so, due to AAC not being supported for DVD audio, unless you're referring to a quality difference due to the source being AAC, then no it shouldn't. There's a theoretic quality loss when you re-encode, but that's not related to the source type.
Do you know what type of audio the source has? It might be AAC but if it's AC3 I'd imagine a decent conversion program would have an option to copy the audio, rather than re-encode it, and if the source was AC3 and you selected to convert to AC3, it'd probably be good if the program had an option to ignore you and copy it anyway..... unless you're re-encoding using a lower bitrate or downmixing to stereo etc.

I can't offer more specific advice because I haven't used ConvertXToDVD in years, but try AVSToDVD to see if the same thing happens. If the programs have an option to downmix 5.1ch to stereo, try re-encoding a section of the source with that enabled, and then disabled, too see if that makes a difference.

I wonder if the soundbar is downmixing to stereo using a standard formula, or if it's boosting the centre channel or altering the audio in a way it can't for stereo audio, due to the latter not having individual centre/surround channels. I don't own one so I'm thinking out loud there.

[JVRaines]

Turn it up. If the effects and music then become too loud, it's a problem with the mix. If you just don't like turning up the volume, then it's probably evil Dialogue Normalization (dialnorm). Try setting it to 31 if your conversion software allows.

[theewizard]

What does the audio sound like when the video is played on your pc?
The same or better
Try comparing the sound of a retail DVD
On the pc and on the DVD player
Maybe you need a new DVD player