Banjo Hangout Logo
Banjo Hangout Logo

Premier Sponsors

343
Banjo Lovers Online


Want to hide these Google ads? Join the Players Union!
Feb 11, 2019 - 7:18:44 AM
1167 posts since 2/12/2009

I have been converting some of my old minidiscs to mp3 format lately and have noticed what I am informed is compression making the sound kinda wow and flutter almost like somebody was fooling with the volume pot ! is there anything I can do to remedy this ? being a bit dim at such stuff I am scratching my head over this one !

Feb 11, 2019 - 8:45:36 AM
Players Union Member

DC5

USA

4083 posts since 6/30/2015
Online Now

Without getting too technical, sound can be expressed as a sine wave. With analog sound this wave is moved to a mechanical device, like a record or tape. With digital sound you break up that sine wave into tiny pieces, represented by a series of 1 and 0. The smaller pieces you make, the closer the sound is to the original. Wav files come the closest to mimicking the original sound and really good wav files are very large as they break the sound up into the smallest pieces. (Digital photography does the same thing.) Old phonograph records come the closest to the actual analog sound, which is why they are seeing a resurgence. When any digital file is compressed it is passed through an algorithm that removes some of the 1s and 0s, making the file smaller. For example lets say that the digital representation is 1000110111100010101. This could be compressed to 130210413010101. The 3, 2, 4, 3 are not actual numbers, but a computer code representing them. In other words there is a code that says the next 3 bits are 0s or the next 4 are 1s. You will always lose some detail in the compression. Kind of like reading a Reader's Digest abridged version of a novel. I hope this makes sense.

Feb 11, 2019 - 11:23:32 AM

53 posts since 11/27/2017

Simple answer - don't compress them. You should be able to choose a conversion that simply "wraps" the digital files you have in a new format. You could use Apple Lossless as the format, or -- failing that -- make sure that the mp3 conversion is set to the largest "number" possible for bits per second. If you compress your DAT files to 64kbps, they are going to sound bad. I use 360kbps as a basic standard, and for stuff I really care about, shift to Apple Lossless.

Feb 11, 2019 - 12:56:09 PM
likes this

6356 posts since 2/14/2006

quote:
Originally posted by spoonfed

I have been converting some of my old minidiscs to mp3 format lately and have noticed what I am informed is compression making the sound kinda wow and flutter almost like somebody was fooling with the volume pot ! is there anything I can do to remedy this ? being a bit dim at such stuff I am scratching my head over this one !


What they already said.  Basically, mp3s are compressed files anyway.  So to some extent, you will hear this happen with mp3s.  But there are different quality mp3's.  When you're converting, you're probably using 128 kb/s conversion.  If they give you an option to convert to 320 kb/s, do that.  It takes more processing power and instead of the song being a 3-4MB file, it might be a 7-8MB file, but the quality will be much better.

 

OR, just convert to WAV files.  No audio loss in WAV files.

 

doug

Feb 11, 2019 - 3:44:09 PM

2164 posts since 4/16/2003
Online Now

Minidisc to mp3? I've done that.

You want your mp3's to be 256kbit or higher.

That should do fine.

Feb 11, 2019 - 10:11:18 PM

dr4dpet

USA

580 posts since 2/9/2016

In the short term, a compressed format (lossy) will serve your listening purposes.  They have the advantages of being smaller files and most people never notice the difference between them and uncompressed formats when a larger bitrate (the 256 or 320 mentioned above) uncompressed format is used. The larger the bit rates give you bigger files. You may also see mention of Variable Bit Rate (VBR) compression for the same formats. VBR would indicate greater compression on the silent or less complex sections of the file, resulting in smaller files.

Probably the greatest advantage of the uncompressed formats (lossless) is that as you make copies of copies of the compressed formats you may begin to notice the introduction of artifacts. This shouldn't happen with the uncompressed formats. Probably the ideal, if you have the storage space and time to invest, would be to have a master copy of your files in an uncompressed format and a compressed version for use on computers, phones, media players, thumb drives for use in vehicles. 

The most common of the lossy formats is mp3 format. Another format in common use, that is suitable for most all devices is ogg vorbis. The more common lossless formats would be .wav, alac - the apple lossless mentioned above, and flac. (Unless things have changed you will need a 3rd party player to use flac on apple devices. Flac is natively supported in Windows, Android, and LInux.) Personally, I use ogg vorbis and flac.

Note: There is a difference between audio format and container type and I knowingly misused them in my discussion while sticking to the most common useage forms.

Feb 12, 2019 - 8:05:56 AM
likes this
Players Union Member

rudy

USA

13471 posts since 3/27/2004

quote:
Originally posted by spoonfed

I have been converting some of my old minidiscs to mp3 format lately and have noticed what I am informed is compression making the sound kinda wow and flutter almost like somebody was fooling with the volume pot ! is there anything I can do to remedy this ? being a bit dim at such stuff I am scratching my head over this one !


Lots of good information has already been posted, but the problem most likely stems in the conversion process between Sony's proprietary compression format which the disc was originally recorded with (various versions of ATRAC) and whatever happens to do the mp3 conversion by the method you are using.

The compression depth set for your mp3s will make a differance in the overall quality but will NOT cause volume "pumping" of the recorded material.  The minidisc process requires the compressed information is de-compressed when it's being listened to, so it's most likely happening in that process.

Most listeners find 320kbs mp3s to be close enough to CD quality that they can't tell the differance on most listening devices, but many folks use 128kbs as a good trade-off between storage space used and sound quality.  For most music there isn't that much of an audible improvement between 128 and 320 to really notice.

128kbs is the default standard for mp3s to be uploaded to Banjo Hangout, so consider that.

If you notice the volume changing cyclicly during playback it's due to improperly implemented compression, not the mp3 format regardless of bitrate.

Feb 14, 2019 - 11:29:28 PM

dr4dpet

USA

580 posts since 2/9/2016

Building on what Rudy said. 

You didn't mention what OS is installed on your computer, but knowing that most people are using windows; Microsoft released additional support for various Sony ATRAC and AMR audio (and video) codecs as an option update to windows 10 four months ago - October 2018. Check if you have this update installed. (We can only hope the solution is as simple as this.) Furthermore, Win 7 didn't come with full support either, even these are old codecs.

IF you are on Linux, the ffmpeg library supports ATRAC and AMR codecs.

Hangout Network Help

View All Topics  |  View Categories

0.171875