I expected a lot more audio quality form a €2500 laptop. I just can't believe the audio quality is that bad. it is just like the computer sends out music with the equalizer, used for the internal speakers.
Please, stop jumping to conclusions, and start troubleshooting methodically.
First suspect has to be the cable... If the cable is bad, then you will get weak and distorted sound. If the cable is improperly shielded, you will get interference. So; get a known good cable and test. I'll lay 2:5 odds that the cable is the primary problem.
Then, for both yourself and the poster with the sound system at church; the gain has to be staged properly on any source/preamp/amplifier system. Too little signal from the source means excess noise because the preamp has to be cranked up to bring the signal (and all the noise) up to the level that adequate amp output can be achieved. Conversely, too hot of a source signal will distort the inputs of the preamp/mixer channel. Also, the preamp, mixer or speakers has to be set for (and capable of handling) the level of input from the source. Often mixers have a mic./line setting, or a 10 dB pad, which is switchable. On a preamp, use the AUX or Tape In jacks, not the Phono jacks.
Do not, under any circumstances, attempt to use the software EQ and compression in the Mac (iTunes or whatever else) to improve the sound of the reproduction system. It will only make it worse. Turn off all software EQ and effects.
There remains a possibility that the Mac is defective, so if all other tests have been done, then take it and your speakers to your local authorized Apple service centre and test it with them. Don't be overly surprised if it turns out the machine works well with other speakers...
And finally: You want to do professional level audio. You have spent €2500 on a machine. So spend €100 - €300 and get a professional level digital audio interface -- Firewire or USB. You will get better sound quality and much more flexibility. This is no different from buying a Mac and complaining that TextEdit doesn't do a professional job of page layout -- you need to buy the appropriate additional tools for the job you want to do.
percuisly, its a state of the art laptop, it should be extrordinary sound quality, people use these things for recording music for god sake
Yes: And they buy pro-quality digital audio interfaces to record with. The Mac doesn't come with a built-in pro quality recording interface because 90% - 95% of owners will never use it for that. Just like it doesn't come with Photoshop, or Maya or Cubase.
