I am looking for an audio editor (it does not matter if it is free or not). I am starting to learn music and how create and edit in Mac. I want a simple but still powerful enough application to edit audio files and apply some effects. I come from Linux, so, and the obvious choice would be Audacity. What other alternatives do I have (may be more "Macish")
I don't know how "Macish" it is, but Reaper is inexpensive, easy to use, and has an excellent guide called "Up and Running" (PDF) that will quickly get you started using it. It also has a free 30 day trial period so you can check it out properly.
I have used Audacity for recording, and found adding effects to be tedious. With reaper you simply add the effect to the track and adjust it in real-time.
Do you have Garage Band? It's really quite a powerful sequencer. If you don't have it, I believe it can be purchased through the Mac App Store for not much. I'm not sure if it fits what you mean by a sound editor though. If not, then I'd suggest you use Audacity as: a) it's free, and b) you know it already, having come from Linux.
Ardour would be the F/OSS alternative to Garage Band.
TwistedWave is available from the Mac App Store for about $80. I don't have any experience with this program but it's a sound editor as opposed to a sequencer.
I know it is expensive, but Logic Studio comes along with Soundtrack Pro. It's a great program allowing for powerful waveform editing.
I jumped straight into it and bought a video training from Lynda.com. It's not really the easiest editor after all but for the Mac I guess it's by far the best one. Most other stuff I've discovered always was about Midi and making music. Sequencers, etc, but very poor or no waveform editing capabilities.
Audacity is nice but I find it very hard to use.
And then there's also SoundBooth from Adobe. I don't know it's price though but guess it's insanely expensive. I've got that as well inside my CS5 Production Premium package but haven't ever used it. From what I know by watching some about videos, it's comparable to Soundtrack Pro from Apple.
Note that Soundtrack Pro has been developed with a strong focus on sound editing for movies, so there is a lot of "interface chrome" going on for this kind of stuff.
I'm not sure if there's a "real" standalone wave editor for the Mac, besides Audacity, which does it the "Apple way" (easy to use, great user interface, etc.).
Garage Band is comparable to Logic Pro 9 but imho not very useful for sound design, just for making music.
After all I am a beginner though so you shouldn't take my advice for granted ;-)
Ableton Live is a recording and production program which might fit your needs. It's simple to use, and it can handle most production tasks. I've used it over 2 years and I haven't yet found a task that I cannot solve with it.
It's not a Logic Express or Logic Pro level tool, but it is more like Garage Band in price and ability to do a lot of high quality work with only a little investment in learning and cash.
I use Amadeus Pro for quick editing. It doesn't have as many features as Audacity but it's more responsive and definitely feels "more Mac". I'm not sure it's $60 better than Audacity - I got it cheap as part of a promotional bundle - but it's worthy of a look.