I watch your course about common panning mistakes. There is a video called stereo spread. As you are using a word monitoring there, I understand the video is about the real instruments, at the moment about the real speakers, and thus it has nothing to do with me? So if I pan with built-in speakers, I couldn't make the stereo spread mistake mentioned on your video... ?

If your song will ever be listened to by others, on their own systems, then you should mix on regular (normally-spaced) speakers so you'll be able to tell how the panning will work on other systems as well as your own (you should also check the mix in headphones as well). If you're the only one who'll ever be listening to your songs, and you don't have separate speakers, then I guess I wouldn't worry about it too much, but I wouldn't say that issues of stereo spread would not exist in your mix, you just wouldn't be able to tell until/unless you listened on normally-spaced speakers.

So, if I don't want to buy the regular (out of garageband) speakers, I still can pan with built-in speakers, but the result of the pan I also can listen to with headphones? As I want my song will be listened to by others, but I don't want to buy the regular (outer) speakers.

Yes, you could mix/pan while monitoring with the built-in speakers and headphones. Panning aside, the sound quality of the built-in speakers will not really be good enough for professional mixing, but if you're not worried about that, and if the headphones have decent sound quality, then I guess that could work ok.

You write not be good enough for professional panning the sound quality of built-in speakers. Well, how bad it could be then? For example, if I listen to the song on the radio, they all seem good for me. But I have heard that Fancy, the group from 80's, has not the best quality. But I myself couldn't listen to it - Fancy sounds to me as good as other singers. Do you feel difference between Fancy and other group? Is the Fancy quality 'not good enough' for you? Or do you have any examples about panning with built-in speakers and the same thing with outer speakers? It is interesting for me to listen to the difference.

A professional mix that's distributed to the public has to sound good on the various different systems it may be played on, so professional mixers monitor on good speakers, properly arranged for stereo imaging, and also check the mix on other systems -- smaller speakers, bigger speakers, crappy speakers, headphones, earbuds, etc -- to make sure it works on many different systems. They also try to mix in a room that doesn't overly color the sound. Most likely anything you hear on the radio will have been mixed and mastered to this standard, so while mixes all sound a little different in tonal balance and dynamics, they all should be up to certain standards of what's considered professional quality. That said, those standards -- and mixing preferences -- change over the years, so 70's songs have a different sound than 80's songs, etc etc. If you plan to market your music then you would need to pay some attention to how your mixes sound compared with other commercial mixes. Or you could have them mastered professionally -- part of a dedicated mastering engineer's job is to make sure a mix meets current professional standards. On the other hand, if you're just distributing your mixes casually, or to friends & family, then that's not so important and I wouldn't really worry about it at this point.

If I don't want to buy regular speakers but want to get professional quality, can I buy that work of mixing/panning? Any idea, what the cost may be or what is the cost of decent speakers?

Decent monitors that would be ok for mixing might range from small speakers for a couple hundred dollars each to a few hundred dollars each, up to models that cost thousands of dollars. When you say "buy that work of mixing/panning" I take it you mean hire someone to mix your music for you? If that is what you meant, then yes, there are plenty of commercial mixing services -- just Google "mixing services" and you should get plenty of results. This discussion seems to have moved away from the specific thread topic of panning to a more general topic of mixing considerations -- please start a new thread when the topic changes..

I don't understand one thing. You write that I should check the mix in headphones as well. Is it means, that decent headphones are the same good for mixing/panning as the regular speakers? Because I believe the speakers are big and loud and I don't like that kind of stuff. If the headphones are same good, then no problem, I try to mix by myself (no need to hire anybody).. Hope this is still panning question.. ?

No, headphones are not the same as speakers for mixing -- mixes done on headphones may sound different when heard on speakers, and not as good on speakers as mixes done on speakers. Most professionals mix on speakers, because those mixes usually translate better to headphone listening than vice-versa. But a professional mixer will need to hear the mix on both speakers and headphones, good and bad, and make adjustments to make sure it'll sound ok everywhere. Of course you can always choose to mix yourself, and not worry about any of that, especially if you're not ready to, or not planning to, commercially release your music -- it's up to you. Keep in mind that mixing is a skill that requires a good deal of time and practice to be able to do well.. The last few posts in this thread seem to be about general mixing considerations -- whether to mix on speakers or headphones, commercial mixing services -- and not specifically about panning; please start a new thread on mixing for any discussion on that topic..