Converting MP3 to higher frequency - Poor Quality

[Unregistered]

Hi Everyone,

I have telephone conference calls on MP3 format and I need to convert to a higher frequency in order to load it onto my MP3 player. The problem is, every time I convert it, the quality is horrible and I can barely understand what anyone is saying on the conference call.

Any idea on how I can fix this issue?

[ChristinaS]

Re: Converting MP3 to higher frequency - Poor Quality

Hi Everyone,

I have telephone conference calls on MP3 format and I need to convert to a higher frequency in order to load it onto my MP3 player. The problem is, every time I convert it, the quality is horrible and I can barely understand what anyone is saying on the conference call.

Any idea on how I can fix this issue?

As it happens I was just reading and article in Puget Sound Computer User (www.computeruser.com) about www.octiv.com. The article was called: Calling All Callers: Octivox's Clear Call. They talk about a device that can be installed between the phone and the phone jack to improve audio.

Apparently there are also software solutions for this.

[Unregistered]

Re: Converting MP3 to higher frequency - Poor Quality

The thing is, I have no problem with the original MP3 file. The conference call is very clear when I listen to on my workstation. It's just that when I try to convert it to a higher frequency from 8000Hz to 16000Hz, the quality is awful. I have no problems converting the frequency of MP3 music files, just with these MP3 conference calls.

[ChristinaS]

Re: Converting MP3 to higher frequency - Poor Quality

The thing is, I have no problem with the original MP3 file. The conference call is very clear when I listen to on my workstation. It's just that when I try to convert it to a higher frequency from 8000Hz to 16000Hz, the quality is awful. I have no problems converting the frequency of MP3 music files, just with these MP3 conference calls.

Hmmm... this is a problem of a different nature then.

Are you maybe converting to stereo while the original may have been mono?

I have done this with a a mono audio file, but at the same time I also converted it to 16-bit stereo and applied numerous other transforms to the wav so as to enhance it (echo, etc). The result was somewhat of an improvement for the song, but it can cause problems for speech.

[xoas]

Re: Converting MP3 to higher frequency - Poor Quality

Unregistered-
You may want to check your dMC Configuration. Go Start>All Programs>dBpowerAMP Music Converter>Configuration>dMC Configuration. Under the button that reads ID Tag Options is a box to enable Professional Frequency Conversion. If it is unchecked (the default setting) check it. Professional Frequency Conversion is supposed to reduce problems that may arise from converting a file from one frequency to another.
Best wishes,
Bill Mikkelsen

[Unregistered]

Re: Converting MP3 to higher frequency - Poor Quality

Thanks for the replies!

ChristinaS, I've already tried converting it to mono. In fact, I've even tried replicating the exact same settings of the original MP3 file.

Bitrate: 40Kps
Frequency: 8000
Channel Mode: Mono

You would think the outcome would sound the same, but it came out worst.

xaos, I tried your suggestion of turning on the Professional Frequency Conversion, but the results are the same.

I'd hate to have to return my MP3 player because I can't convert my MP3 files properly, I got a terrific deal on it. But I've tried other converters with the same results and I'm running out of ideas.

[ChristinaS]

Re: Converting MP3 to higher frequency - Poor Quality

Thanks for the replies!

ChristinaS, I've already tried converting it to mono. In fact, I've even tried replicating the exact same settings of the original MP3 file.

Bitrate: 40Kps
Frequency: 8000
Channel Mode: Mono

You would think the outcome would sound the same, but it came out worst.

xaos, I tried your suggestion of turning on the Professional Frequency Conversion, but the results are the same.

I'd hate to have to return my MP3 player because I can't convert my MP3 files properly, I got a terrific deal on it. But I've tried other converters with the same results and I'm running out of ideas.

Then why are you converting the files to a different frequency? Leave them be. Or is that what's required by your MP3 player?

I didn't know you were using an MP3 player, I thought you were playing them through your pc. MP3 players may require higher fidelity files which these obviously are not.

[Unregistered]

Re: Converting MP3 to higher frequency - Poor Quality

Then why are you converting the files to a different frequency? Leave them be. Or is that what's required by your MP3 player?

The reason I need to convert is because the MP3 player doesn't support audio files at such a low frequency. I think I need to file at a minimum frequency of 16000Hz.

[ChristinaS]

Re: Converting MP3 to higher frequency - Poor Quality

The reason I need to convert is because the MP3 player doesn't support audio files at such a low frequency. I think I need to file at a minimum frequency of 16000Hz.

Are you converting directly mp3 to mp3?

I'd be tempted to convert first to a wav of higher frequency, mono, and then to another mp3, of the same frequency, mono as well. It may make no difference actually. But having a wav allows for some wav manipulation.

Oh, and maybe you shouldn't use Volume normalize (if you're using it) as it sometimes actually deteriorates the audio quality.

Finally, maybe you want to use a capture to wav through dMC Auxiliary Input, followed by a conversion to mp3, rather than a straight conversion between mp3's.

And I'm fresh out of ideas

[dbample]

Re: Converting MP3 to higher frequency - Poor Quality

Hi Everyone,

I have telephone conference calls on MP3 format and I need to convert to a higher frequency in order to load it onto my MP3 player. The problem is, every time I convert it, the quality is horrible and I can barely understand what anyone is saying on the conference call.

Any idea on how I can fix this issue?

This is likely because mp3 is a lossy compression, and converting from that to anything esle, including exactly the same format and bit rate or higher bit rate, results in a worse copy of it. Secondly, you can't invent the data that was lost when it was recorded in the original mp3 low bit rate, so converting it to a higher bit rate is definitely not going to improve quality (I know you are not claiming that and you only want to do it for compatibility with your mp3 player, but it is a point worth making). For the afore-mentioned reason, though, it is in fact going to degrade quality no matter what you convert it to.

So my take on this is that it is likely not because of something you do wrong during the conversion, but because of the inherent drawbacks of manipulating an mp3 low bit rate audio file.

[xoas]

Re: Converting MP3 to higher frequency - Poor Quality

Unregistered-
To test out your problem I have created a mono mp3 file at 40 kbs and a frequency of 8,000 khz. I then converted this to a 128 kbs joint stereo mp3 file at 16000 khz and at 44,100 khz frequencies. Without professional frequency conversion the results were not pretty but with professional frequency conversion the results were listenable.
BEFORE TRYING ANYTHING HERE, PLEASE CHECK MY NEXT POST BELOW. SHOULD the advice there not work then go ahead and consider the following:

You may want to check the file tag for your source files. It may be that a different mp3 codec might work better. I am using the dMC release 11 beta which uses a new and different mp3 decoder and you may want to consider trying this. The new decoder is supposed to be an improvement in reading atypical mpeg files. You can download the dMC release 11 beta from the Betas section of this forum. BTW-I am using the dMC r 11 beta.
Your problems may lie with your original source files, however, since the quality of the original material was probably not that great. On the other hand, if it sounds ok on your computer you could try converting the files to wav and then to mp3 by recording them through the sound card using dMC Auxilary Input.
Best wishes,
Bill Mikkelsen

[xoas]

Re: Converting MP3 to higher frequency - Poor Quality

Ok. I've spent some time in contemplation of this problem while washing dishes. I've changed my opinion slightly. I think the capabilities of your mp3 player are likely to be at the root of your problem. Check out the documentation you have for your mp3 player (or look it up if you don't have a manual that is helpful on this subject). Find out what frequencies and bitrates and etc. your mp3 player supports. It may not necessarily recognize files with a 16000 khz frequency, or files at whatever bitrate you are converting to, or mono files, or variable bitrate files (if you are using a vbr setting).
So first, figure out what your player supports. Then try converting to those settings (and yes, do enable Professional Frequency Conversion). Or, as a shortcut, try converting one of your files to some setting you are positive your mp3 player will recognize (such as joint stereo, 128 kbs cbr, at 44100 khz) just to prove you can do it and then you can toy around with how far you can adjust the conversion to still have it playable on your mp3 player.
Only if that doesn't work would I advise trying to change codecs or going with dMC release 11 beta.
Best wishes,
Bill Mikkelsen

[Unregistered]

Re: Converting MP3 to higher frequency - Poor Quality

SWEEEEEEEEEET!!!

It worked! I used the dMC release 11 beta and it worked!

Thanks everyone for going through this with me! I really appreciate the efforts and I apologize for invading your minds during dish washing time.

[ChristinaS]

Re: Converting MP3 to higher frequency - Poor Quality

SWEEEEEEEEEET!!!

It worked! I used the dMC release 11 beta and it worked!

Thanks everyone for going through this with me! I really appreciate the efforts and I apologize for invading your minds during dish washing time.

Great!

What are you going to use as motivation for dish washing, Bill, now that this problem has been settled?

[xoas]

Re: Converting MP3 to higher frequency - Poor Quality

It worked! I used the dMC release 11 beta and it worked!

Congratulations!