why does output peak when other levels are fine

Because signals add up. You have 10 tracks going into 1 output, each extra track will contribute to the loudness at the output. The position of the faders only tells you what is subtracted from the audio's actual level. So if you have, say, drums that peak at -3 dBFS, lowering its fader to - 5 will mean it now peaks at -8 dBFS.

Since your highest "over" is only 0.1 dBFS, it is not a huge problem. You could either drop your output another 0.5 dB to -1.5, or use a Limiter on the output.

http://help.apple.com/logicpro-effects/mac/10.1/#/lgcef1becd08

Eriksimon gave you the proper technical explanation and I just want to add a real-life analogy:

Assume you have 5 glasses of beer (5 Channel Strips), each one is half full (-6dB). Now if you pour (route) the content of those five glasses into a single new glass (Output Channel Strip), then it will over flow (clip) - Prost 😁

Hope that helps

Edgar Rothermich - LogicProGEM.com

(Author of the "Graphically Enhanced Manuals")

http://DingDingMusic.com/Manuals/

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