lossless equalizer for MP3 - does it exist?

Hi, would Audacity assist you?
http://audacity.sourceforge.net/
http://www.guidesandtutorials.com/audacity-tutorial.html

Are you saying that you are noticing changes in the EQ when creating MP3s?
I suppose it's fair to say firstly that MPEG's MP3 compression algorithm has been superceeded by MPEG's AAC algorithm.
Of course MPEG's main aim was not to loose quality in the frequency spectrum when encoding to either Mp3 or Mp4 -- so they've done all they can with the algorithm. After all they are both lossy compressions by name. I personally don't have a problem with high bit rate mp3's or MPEG-4 AAC files -- but some audiophiles say on certain equipment, under certain conditions that they can detect differences. It's a bit picky for me.

...just adding. I don't hear that many people complaining about the quality of CDs, which are encoded at 16 bit 44.1Khz -- a very old, low standard -- when a lot of sound today is being processed at 24bit 96kHz.
For each standard there is an Eq algorithm -- as there was one for Vinyl records, which was called the RIAA equalisation.
But realistically all audio should be re-equalised in real time for each room it is played in or for any device that it is played through. That's because the eq is designed in flat rooms but rarely replayed in flat rooms -- like the eq for a system in your bathroom will be entirely different to that of a living room.

Merete: Audacity is lossy. (decodes, re-encodes) ...I think.

Fredshovel:

Good point. Let me clarify - I'm looking for an MP3 EQ which will not degrade the MP3 *FURTHER*.  ie- Most audio editors will decode the MP3, allow editing (like EQ), and then re-encode it into MP3, thereby degrading it further.

While an app like mp3Gain does not decode/re-encode, it operates on the MP3 data directly.

I have some MP3's which could use more bass, so I'm wondering of I can add bass (to the MP3 itself) without any loss in quality resulting from decoding/reencoding.

-Soy

Thanks...