Audacity Forum

Hi and thanks to all those associated with Audacity for providing such an excellent programme and service.
I am an amateur home studio musician.
I am having a problem with files I export from Audacity in MP3 format.
When I complete a track it sounds absolutely fine when played through Audacity.
However, when I export as MP3 the lower frequencies, notably the bass, are way too high and sound distorted.
Of course I can reduce the velocities through effects-amplify or by changing the gain, but this just makes the track quiter. When the sound is turned up, the distortion remains.

I could of course make adjustments (equalisation and the like) in Audacity, but shouldn’t I get from the exported MP3 file more or less exactly what I hear from the Audacity output?

Would a useful first step be to upgrade my version of the Lame encoder?

Should I export the whole Audacity file as a WAV and then use a different programme to convert to MP3?

Has anyone else come across a similar problem?

Any help gratefully appreciated.

Try exporting to wav temporarily, does that sound ok?

I could of course make adjustments (equalisation and the like) in Audacity, but shouldn’t I get from the exported MP3 file more or less exactly what I hear from the Audacity output?

More or less, yes. You should get an mp3 representation of the project. As long as the mp3 bit rate is high enough, everything should be fine when you export.

My guess is you've got Audacity set to export to a low bit rate. In the Edit -> Preferences -> File Formats menu, change the mp3 bit rate to at least 128 kbps (preferably 192 or higher, if you ask me).

At that bit rate, the exported mp3 file should sound more or less exactly the same as the Audacity project.

One more thing to be aware of, if you have any tracks that are normally muted in the Audacity project (like a drum machine, or a guide track), they will show up in the exported file when you use the File -> Export function (this is really irritating to me, I wish it were different). You'll either have to remove that extra track (don't save after doing this), or highlight everything you want and nothing you don't and use Export Selection.

Also, you can't upgrade the lame_enc.dll file, it works the same for everyone.

Many thanks for taking the time to respond, alatham.

I'm pretty sure the bit rate is set to 128 kbps (am writing this from the office!) but will check when I get home.

Also will try a 15-20 sec. extract at 192 and see what happens.

Yes if I export to WAV (again I just pick out a 'noisy' 15-20 second stretch to save time) that comes out just fine.

Thanks for the muted track tip - I think I would have thought of that one - but on the project in question nothing was muted.

That's what I figured about the encoder. It either works or it doesn't!

Anyway, am not running out of options yet. I have a second PC (older, different sound card - different everything in fact).
Will try to make an MP3 on that. If I get the same result then yes I have a problem!

THanks again - regards, Marc

Hello Marc,

Hope you don't mind my butting in on your thread.

I don't have much to offer except that I believe the sound card is the culprit.

I have a similar problem. I am putting some of my old cassettes into mp3. I don't have the knowledge that you do about filters and things like that, but I have tried pretty much everything in the Audacity menu that might have relevance to their being too much bass and it makes little difference. The volume is reduced, but not the bass

When I initially record the track(s) into Audacity the bass is more than on the original. And when I convert into mp3 the effect is compouned. .

I find that the bitrate makes a difference to the quality but not the bass.

Echo your thanks and appreciation to everyone at Audacity.

Pete

Pete, you and Marc have two different problems.

Pete, I believe you have a bad sound card, since you can't record properly. If you can listen to the output of the Walkman somewhere else (plug headphones into it, or plug it into a receiver) and it sounds ok there, then you should be getting the same quality when you plug it into your Line In on your sound card. Unless your sound card is faulty.

But Marc's problem is in no way related to his sound card. If you can record the project using Audacity and it sounds good there, then the sound card is not to blame. Something is going wrong with the export function (or something is set wrong), but I haven't been able to figure it out.

Marc, can you try exporting as a wav and using a different program to convert to mp3 as you suggested earlier? If you need free software to do this, I think this should do the trick:
http://www.download.com/WAV-to-MP3-Enco ... 84935.html

Thanks Pete for your input.
As Andy says, the card seems to function fine for recording/playing Audacity (and, indeed, the audio tracks it deals with in another programme I use, Power Tracks Pro Audio).

Interestingly (or, not, perhaps) it is a higher spec sound card than the one on my other PC where, apparently, I can make the MP3 exports without a problem.

I’m assuming that when you’re recording those old cassettes Pete you do so from a hi-fi system which allows you to control the bass (and set it to close to zero). This might help.

Back to my problem – I will do as you suggest Andy and try to proceed using other means of conversion (but wouldn’t that still be going through the same CODEC ?)

Wierdly, the MP3 export seems to go through just fine on my older PC (see here for result
http://www.soundclick.com/bands/songInf ... ID=5932018) but in both cases I’m using the same version of Audacity (1.2.6) and the same encoder. Could this be a driver-related thing? I have ASIO4all on the newer set (which has an Audigy SE card) and the ‘standard’ Creative Labs driver on the older PC with its SB Live card.

Of course, in a sense that’s problem over as I can always use the other PC to perform the export but as with all these things one would like everything to work proerly everywhere!

Thanks again,

Marc

Well, I still have a hard time believing the sound card is at fault here, but I do know that Audacity doesn't support ASIO drivers (for legal reasons, not practical reasons). I'm surprised it works at all, unless you recompiled Audacity to support the Steinburg code that they supply (which is legal and apparently works, there's a page on the Audacity wiki detailing this if you're interested).

Could you try rolling your drivers back to a WDM set and seeing if that helps? I'll be very surprised, but at this point I think we're both shooting in the dark.

Back to my problem – I will do as you suggest Andy and try to proceed using other means of conversion (but wouldn’t that still be going through the same CODEC ?)

Not necessarily. Not all programs use the LAME encoder, though most do. But it's still up to the software writer to implement the LAME encoder and if Audacity isn't implementing it 100% correctly I'm sure the developers would like to know.

Thanks again for your help, Andy (do stop when you get bored)

Tried disabling ASIO4ALL for the entire card – no change

Various settings which may/may not have some relevance are given below :

Device Control :
PCI / USB tab
Quality of Audio OUT
48 Khz / 24 bits

SPDIF tab
Sample rate of SPDIF OUT : 48 khz


ASIO4ALL 2.7 (apparently is installed & running and seems to be working ok with Audacity)

SB Audigy card
IN 2x 8-96 kHz, 24 Bits
OUT 6x 8-48 kHz, 32 Bits

AC97 Troubleshooting : « Always resample 44.1 kHz – 48 kHz » is ticked
« Force WDM driver to 16 Bits » is not ticked

AUDACITY

MP3 Export set up
LAME v3.96
Bit rate 192


As a conclusive test, I have just imported a commercially produced track from MP3 into Audacity (plays fine). I then re-exported a passage as MP3 and I get the same disproportionate amplification of the bass frequencies.

So it has nothing to do with the quality or otherwise of the Audacity tracks I create myself.

Following your advice earlier in the week, proceeded the same way but using Wav to MP3 Converter 2.5.0 (having changed none of the default settings) to perform the conversion…

Ha, Eureka (well sort of), but I think we have made some progress here.

The converter was not happy converting a mere 20 seconds of my WAV into MP3. It froze. I checked out the help pages to find why and learnt that this programme is only really happy working on 16 bit WAV (see below *)

So I re-recorded my extract as 16 bit wave and, sure enough, playing this WAV back as a test just to see what it sounded like, I find that it too has the over-amplified bass.

Over to you, Andy…


*
Encoding Process Gets Stuck
This happens, again when your WAV has errors in it, or if it is not a 16-bit WAV. Missing bytes or corrupted areas of the song can disrupt the encoding process. Your wav can have these problems if it was decoded from an mp3 at a low bitrate or if its ripping process was interrupted. To avoid this problem, make sure your wavs are of the highest quality. This means that your wav should not be missing any of its song and is ripped fully and properly from the CD. Our encoder typically takes only seconds to encode each MP3, so if it takes too long, you know you should change the sampling/bitrate or your WAV is unsupported.

Oh man, this is wracking my brain.

It seems like a longshot, but when you listen back to these mp3 files, are you always using the same program? Does that program have an EQ applied?

If two different programs are causing the same problem, then that seems to reason that the playback is the problem. At this point, I'm almost totally stumped.

Have been listening back to the MP3s using WMP9, which I don’t think has an EQ, although it does have a volume. The bassy ones sound wrong. Then without changing a single thing in the configuration I can listen to other MP3s – either ripped from CD or recorded elsewhere – and they sound OK.

Plus when I listen to one of the faulty ‘over-amplified bass’ files on another set, they still sound wrong.
So playback does not appear to be the issue.

And Andy, you’re a young man – life’s too short.

Short of flying you over and getting you to check out everything for yourself, I’m stumped too.

I’ll just invest in a few high-capcity USB keys and more the files up & down between the 2 computers when I need to make an MP3.

Many thanks for the time and thought you’ve invested in this problem and good luck with your own continued music-making.

Marc