Sound distortion on TV

[Ray Groome]

I have just transferred a set of my pte slide shows onto a USB2 memory stick for play back on a Sony TV (model 46HX703). (Using the helpful guidance given by davegee on the 16 Nov 2011- titled MPEG4 Files for HDTV).

The image quality is great but I have encountered unacceptable sound distortion on this high spec TV. No problems when playing back on my computer. The music is from mp3 source. Any suggestions please?

Ray Groome

[fh1805]

Ray,

The first thing I would check is that you do not have a problem with the choice of audio codec. What audio codecs does your TV support? (Look in the specifications/technical details section in the user manual) What audio codec was used when the MP4 file was created? (In PTE, navigate to the drive/folder where the mp4 file is stored and, in the File List panel of PTE's main window, right-click on the video file and select "File Info")

[davegee]

Ray,

Is this distortion with any/every MP3 that you use?

I've never had this problem - with a similar (smaller) Sony.

If you could make a small (file size) example then perhaps one or two of use could try it out for you?

DG

[fh1805]

A further thought strikes me... If you used an MP3 file as your soundtrack and IF the creation of the MP4 has generated an MP3 audio stream, then it is just possible that you have compressed an already compressed audio file. MP3 compression is a lossy compression that damages the audio. If you have a doubly-compressed audio stream then you have added damage to existing damage. If you have the original soundtrack material (as an Audacity or Audition project, for example) then try creating a WAV soundtrack file and using that as input to the MP4 creation phase.

[davegee]

Two thoughts Peter.

Ray says that it is OK on the computer.

I use MP3 files between 192 and 256 for PTE and I have never had the said problem.

Ray,

What's the Kbps for your MP3?

The Sony allows you to set a different "Volume Offset" for each Input - check the SOUND settings when in USB input mode?

DG

[fh1805]

Ray says that it is OK on the computer.

Dave,

Good point. I'd missed that. That implies that there has not been any "double compression" damage.

Peter

[Ray Groome]

Thanks for your prompt responses.

MP3 music and MP4 video are compatible with the Sony TV. The music is 320 kbps.

Your reference to the Volume Offset was helpful as I was having problems with reducing the volume level (but Sony made it difficult to find that control!)

By adjusting the Treble and Volume Offset to minimum and turning off the Sound Enhancer on the TV I have reduced the distortion, but there is still room for improvement!

This is a little disappointing as the use of a USB memory stick is a very convenient way of playing back pte slide shows on a TV whilst maintaining good quality presentation of the images.

( I played the slide shows using the Home/Video menu on the TV- I trust that was correct)

Ray Groome

[davegee]

HOME > VIDEO > USB.

The settings that apply to your HDMI or TV or AV1/2 will apply to your PTE show and each of the inputs has a different Picture/Sound setting. Use the same "starting point" each time and adjust your Picture Sound settings to suit.

I have everything set "flat" on my TV - no "enhancements" whatsoever. I'm not a big fan of Vivid Picture and Cinema Sound and all the rest.......... The only thing that varies is the Volume Offset.

Do you have an external sound system or are you just relying on the built in system?

DG

[xahu34]

A further thought strikes me... If you used an MP3 file as your soundtrack and IF the creation of the MP4 has generated an MP3 audio stream, then it is just possible that you have compressed an already compressed audio file. MP3 compression is a lossy compression that damages the audio. If you have a doubly-compressed audio stream then you have added damage to existing damage. If you have the original soundtrack material (as an Audacity or Audition project, for example) then try creating a WAV soundtrack file and using that as input to the MP4 creation phase.

Two remarks:

• In case of a high quality MP3 file, recoding to an MP3 with 192 kbps or higher does not add that much damage (in my experience)
  
• MP4-videos created with PTE seem to use AAC (not MP3).
  

Regards,

Xaver

[Conflow]

Ray,

These may sound like stupid questions to others, viz:-On your USB-Pen....

Q.1)

Are these PTE.Exe Slideshow Files with Mp3 Sounds ??

Q.2)

Or are they Video-Files and what Video-Format (Audio:M3)??.

Q.3)

In both cases did you "Normalise" the Audio-Tracks before making your Files ?

Thats a common fault as most Sound-Files must be below -90db for TV-input.

See the 'Before' and 'After' attachments.

Brian.(Conflow))

[davegee]

Brian,

I'm not answering for Ray.

These are H.264 MPEG4 files created in PTE via the Publish Menu - I have been doing this for a couple of years now and have never had the need to Normalise or any other procedure to get perfect Sound and Video.

However I don't know what mp3's Ray has used - he says that it plays OK on Computer.

DG

[fh1805]

...Sound-Files must be below -90db for TV-input...

-90dB? What kind of dB are you thinking of: dBSPL, dBFS, dBu, or what? My experience of audio engineering/sound editing/sound mixing, using Audacity, tells me that 0dB is the level at which "clipping" occurs (i.e. the point at which audible distortion occurs). A good sound signal will peak at around -3dB and will probably average between -6dB and -15dB. -90dB is unheard of (almost literally unheard of), it's getting close to the threshold of human hearing.

Peter

[Conflow]

Brian,

I'm not answering for Ray.

These are H.264 MPEG4 files created in PTE via the Publish Menu - I have been doing this for a couple of years now and have never had the need to Normalise or any other procedure to get perfect Sound and Video.

However I don't know what mp3's Ray has used - he says that it plays OK on Computer.

DG

Dave,

I accept what you say we have no argument about that. But firstly we dont know what PTE resources Ray is using

nor his File-formats....He simply said:.."I have just transferred a set of my pte slide shows onto a USB2 memory stick

for play back on a Sony TV (model 46HX703)"...

Secondly ~ What Sound-Tracks he plays on his PC is a matter of personal choice and more to the point, has he got

his "Volume-Card Levels" properly setup because the 'Listening-Volume Control' is seperate from the 'Wav-Control'

which controls the Card-output on most PC's.

"Normalisation" is a requirement for TV-Video and if its not correct you can easily overload the 'Sound-Discriminator'

circuitry within the TV-Set. I certainly know that because I have worked in the Industry for over 40 years and its also

a feature in 'Audacity' (for a reason) ~ and ~ its used in every Studio I have worked in....

So lets get the Answers first...And go from there. (Thats what my reply and attachments with examples were all about).

Brian.

[Ray Groome]

HOME > VIDEO > USB.

Do you have an external sound system or are you just relying on the built in system?

DG

I am using the built in system

[Ray Groome]

Dave,

I accept what you say we have no argument about that. But firstly we dont know what PTE resources Ray is using

nor his File-formats....He simply said:.."I have just transferred a set of my pte slide shows onto a USB2 memory stick

for play back on a Sony TV (model 46HX703)"...

Secondly ~ What Sound-Tracks he plays on his PC is a matter of personal choice and more to the point, has he got

his "Volume-Card Levels" properly setup because the 'Listening-Volume Control' is seperate from the 'Wav-Control'

which controls the Card-output on most PC's.

"Normalisation" is a requirement for TV-Video and if its not correct you can easily overload the 'Sound-Discriminator'

circuitry within the TV-Set. I certainly know that because I have worked in the Industry for over 40 years and its also

a feature in 'Audacity' (for a reason) ~ and ~ its used in every Studio I have worked in....

So lets get the Answers first...And go from there. (Thats what my reply and attachments with examples were all about).

Brian.

Thanks, that sounds interesting. No, I have simply downloaded music from a CD and used it straight into PTE. I know nothing about Normalization and do not use Audacity. But the problem I have is clearly related to clipping as much of the track plays OK- its only the peak notes that distort.

Ray Groome

[davegee]

Ray,

What do you use to produce the MP3 from the CD?

DG

[Ray Groome]

Ray,

What do you use to produce the MP3 from the CD?

DG

Windows Media Player

Ray G

[davegee]

Hi Ray,

See PM.

Have you tried a different track off a different CD?

DG

[Conflow]

-90dB? What kind of dB are you thinking of: dBSPL, dBFS, dBu, or what? My experience of audio engineering/sound editing/sound mixing, using Audacity, tells me that 0dB is the level at which "clipping" occurs (i.e. the point at which audible distortion occurs). A good sound signal will peak at around -3dB and will probably average between -6dB and -15dB. -90dB is unheard of (almost literally unheard of), it's getting close to the threshold of human hearing.

Peter

Peter,

You have taken my Post totally out of context ~ and to correct you on one item "0.db Signal level" is a Tone-Signal

of 1000.Hz Sine-Wave at 0.775Vrms across a 600.Ohm load = 1.Millewatt of Acoustic-Power. (The ISO & CCIR Standard).

In various sections of Audiometry the 0.db-Level refers to different things,viz:-

* In one circumstance its the lowest level of Sound which a Human-Ear can hear.

* In Radio & TV its the Peak-Signal allowed through the Mixers & Modulators prior to Transmission.

* In Radio/TV they use a PPM-Meter at level 5/6 indicating the correct levels below the Peak-level.(BBC)

* With NARTB-Tape Machines they use a VDU-Meter where the 0.db-level is shown as "0" and then +/-.(Sony etc)

* In your Audacity the "0.db Level" is the "Max-Instantaneous-Signal Level" before clipping.(Like VDU Meter).

* In volumetric "Loudness-Levels" 100.db is that level above Zero O.db to which Sounds can ascend/decend

and reducing that by 6.db (2:1) one arrives at 50.db which is the Max-Dynamic-Range of DVDs+CDs+Tape+Discs

as was shown in the "MP3-Loudness Corrector" (attachments) which I featured in my last Post.

So Peter, one needs to know what Reference-Level one is talking about before criticising anothers Post and that

detail was clearly shown in the attachments.

And for the benefit of others atttached is an article from the Audacity-Forum showing how to set levels.

Brian.(Conflow)

(Unfortunately all this is digressing away from Ray's problem).

[Conflow]

Ray,

You wrote,

Quote..."Thanks, that sounds interesting. No, I have simply downloaded music from a CD and used it straight into PTE.

I know nothing about Normalization and do not use Audacity. But the problem I have is clearly related to clipping

as much of the track plays OK- its only the peak notes that distort".

Thats what I had suspected ~ it seems as if the Controls on your "Volume-Panel" are set too high or you had the CD

playing 'too-loud' although you may not have noticed that if you had your Listening-volume set low. To get to your

Volume-Card-settings simply double-click the 'Loudspeaker-Icon' down to the left in the bottom Task-bar.

Set these Controls at Half-way:- Volume-Control ~ Wav-Control ~ CD-Control ~ All at half way.

Check with Audacity which you should download (its-Free). See the "How-to" details in the attachment.

Hope this helps,

Brian.(Conflow)

[davegee]

Hi Brian,

Well, I never knew that before!

That's the first time I have ever heard anyone mention that Level (Volume) Controls had an influence when Ripping MP3 files from CDs?

I have used a variety of programmes over the years to extract MP3 files and WAVs from CDs and none of them SEEMED to be reliant on Volume Controls of any sort?

DG

P.S. Here's WMP's Help file on Ripping - can't find a mention of Volume Control anywhere?

Change settings for ripping music

You can use Windows Media Player to rip (or copy) the tracks from your audio CDs onto your computer, after which the tracks that you rip become files on your computer. There are a number of settings you can customize to make ripping work better for you.

1. Click the arrow below the Rip tab, and then click More Options.
2. Make one or more of the following changes:
   
   • Location. Click Change if you want to store ripped files in a different folder on your computer.
   • File Name. Click if you want to use a different naming convention for ripped files. For information about how to apply changes to the naming convention or storage folder to files you had previously ripped, see the Rip music FAQ.
   • Format. Choose a format for the files that are created during ripping. The default format is Windows Media Audio, which optimizes the balance between file size and sound quality and is supported by PlaysForSure-verified devices. Other available options are:
     
     • Windows Media Audio Pro, which is designed to be used in low storage capacity portable devices, such as mobile phones, where the increased efficiencies of the format improve the audio quality at lower bit rates. Note that not all devices support this format.
     • Windows Media Audio (Variable Bit Rate), which can reduce the file size but may also take longer to rip.
     • Windows Media Audio Lossless, which provides the best audio quality but increases the file size.
     • MP3 and WAV (Lossless), which provide added flexibility.

Your selections apply to tracks you rip in the future; it is not possible to use the Player to change the format of a track you already ripped. If you are not sure which format works best for your needs, you can try ripping to different formats and quality settings and listen to the differences to help you decide.[*] Copy protect music. Select this option if you want ripped files to be protected with media usage rights. For more information about copy protection, see the Rip music FAQ.[*] Rip CD when inserted. If you select this option, you can choose either the option Only when in the Rip tab to have ripping automatically begin after inserting a CD only when you go to the Rip tab or Always to have ripping begin immediately upon inserting a CD. Note that with this feature turned on, you are not prompted to confirm your rip music settings, all tracks are selected for ripping, and that ripping will begin regardless of whether or not you have a connection to the Internet to get media information. If no media information was found during the ripping process, the Player will advise you to manually enter media information after ripping has completed.

These settings are also available by clicking the arrow below the Rip tab, pointing toRip CD Automatically When Inserted, and then making your selection from the menu.[*] Eject CD when ripping is complete. Selecting this check box, in addition to Rip CD when inserted, is useful if you want to rip several CDs in succession.[*] Audio quality. You can adjust the compression quality used during ripping. Choose a quality setting that represents the best balance between quality and file size for your needs. If you are not sure what setting to use, try ripping to different formats and bit rates and then play the files. Note that it is not possible to adjust the quality if you have selected a lossless format.

[Ray Groome]

Ray,

You wrote,

Quote..."Thanks, that sounds interesting. No, I have simply downloaded music from a CD and used it straight into PTE.

I know nothing about Normalization and do not use Audacity. But the problem I have is clearly related to clipping

as much of the track plays OK- its only the peak notes that distort".

Thats what I had suspected ~ it seems as if the Controls on your "Volume-Panel" are set too high or you had the CD

playing 'too-loud' although you may not have noticed that if you had your Listening-volume set low. To get to your

Volume-Card-settings simply double-click the 'Loudspeaker-Icon' down to the left in the bottom Task-bar.

Set these Controls at Half-way:- Volume-Control ~ Wav-Control ~ CD-Control ~ All at half way.

Check with Audacity which you should download (its-Free). See the "How-to" details in the attachment.

Hope this helps,

Brian.(Conflow)

Thanks for all the comments.

The Volume Mixer settings were all set to the 50% mark. The problem occurs on a variety of tracks from different sources.

I have downloaded Audacity and explored the Normalisation facility- but I note you have to specify the the maximum amplitude. Do I accept the default value of -1.0dB?

Ray Groome

[davegee]

Hi Ray,

One final word from me.

Normalising an MP3 which is already clipped is not going to help.

DG

[Conflow]

Ray,

Yes ~ I agree with Dave on this one ~ if its already (overmodulated) "Clipped"

there is nothing you can do about it..except re-record it again but this time

use the "MP3-Loudness Software" to correct any chance of "clipping" thats if you

dont want to use Audacity. If the Files are still "clipped" there is definitely

something wrong with your PC-setup or the Sony-TV.(With Audacity try the default)

Copy of the "MP3-Gain-Program" here attached.

Dave,

The above is a typical example for you ~ All 'Commercial-Playable-Media' use some

form of "Compander" (Compressor/Expander) on the Studio side of things prior to

any subsequent "Print-Burning" on to CD or DVD. Sometimes with 'cheap' Copies as

in Supermarkets things go wrong, God knows why !!! ~ But in Ray's case he has many

Mp3 sources ~ they cant all be wrong ?

Ray,

If you can oblige, I would like to have a look at one of your Tracks to analyze it

and determine if the 'fault' is on your side or on the Sony side of things.

Perhaps with a reply Post you could attach a small Mp3-File <3.Mb in size.

Brian.Conflow)

Mp3-Gain Software below: 625kB. (Windows.Zip File)

[Guest Yachtsman1]

Hi Ray

Just to throw one into the pot, -1 is the usual Audacity default. you can do a visual check by looking at the Audacity waveform, if there are any spikes top and bottom of the track reaching the outside of the track, you have clipping & need to normalise., in case you weren't aware.

Yachtsman1.