This is an answer I wrote to Max on pianoworld.com in response to his posting a video of his tuning and asking for feedback. You can see the video at Max's Tuning Here is my response with step by step instructions how to improve unisons:   Max, you are posting for an objective truth from professional technicians. I will tell you what I think. The unisons are very bad. Someone who tunes as much as you do and cares enough to reach out and look for ways to improve should not be tuning unisons at that low a level. Here is a simple thing you can do to prove this to yourself how bad they are, and also help you tune treble unisons better.

Isolate and Improve Unison Technique

Isolate and Improve. (We improve tunings, we don't make them perfect. The higher your sensitivity to unacceptable unisons followed by subsequent improvement, the better your unisons will be.) 1. Play a few unisons, say within an octave, one after the other. Identify one that sounds the worst. - Use the comparison technique of comparing the trichord unison with the sound of a single string. 1. Identify a unison that may need to be improved. 2. Mute off two of the three strings. 3. Play the note. You are now listening to a single string. 4. Remove the mute. 5. Play the note now, which will be the three strings together. 6. Compare that sound to the sound of the three strings together. 7. If they sound exactly like the single string, then the trichord is as good as you can get it. 8. If you hear that the trichord unison has more shimmering or colour in it than the single string unison, it means the trichord unison is not as good as you can make it. 2. Take that one unison that you have identified could be improved, and mute the left string and play the note. You are now listening to the right two strings only. 3. Take that one unison and mute the right string and play the note. You are now listening to the left two strings only. 4. Which pair sound better? - If the right two sound better, that means the left string could be improved. Remute the right string and retune the left two unisons by retuning the left most string. Remember, make them sound better, not perfect, just better. Remove the mute and listen for the improvement in the trichord unison. - If the left two sound better, that means the right string could be improved. Remute the left string and retune the right two unisons by retuning the right most string. Remember, make them sound better, not perfect, just better. Remove the mute and listen for the improvement in the trichord unison. - If both sound bad, or the same but not like a single string, then there is two possibilities: 1. The centre string could be improved. (i.e. the left and right are close to each other) - Mute the right or the left string and retune the other right or left string until the sound improves. Again, don't look for perfection. - Remove the mute and listen for the improvement in the trichord unison. 2. Both unison pairs are bad. I.e. no two strings are very close to each other at all. - Mute one side and retune the other pair. Mute the other side and retune the other pair. I.e. retune the trichord unison from scratch. In this way, you improve the unisons and continue to improve your internal concept of what a good unison sounds like by producing better and better unisons to hear right in front of you. If you do not improve your internal concept of what a good unison sounds like, you will be doomed to continue to produce those inferior unisons for the rest of your life. Obviously you do not want to do that or you wouldn't be posting on PW.