Symphonic Mixes Class 101 (aka Potion Making)
“Can anyone tell me what exactly a symphonic mix is? Anyone? Anyone besides the insufferable know-it-all Ms. Granger? Perhaps you, Mr. Potter?”
As MHarris has stated, a symphonic mix is a literal “orchestra” of different pheromones and products combining their individual effects together in a reinforcing and blended fashion as to produce new, often unexpected results.
Think of all the components you are using as instruments in your band, and you are the singer. While you determine and guide how the song is sung, your band of instruments creates the atmosphere and backdrop, and how they mesh together and blend determines how well the song will turn out.
As for concentrations, you should have sufficient quantities to generate an effect, but managing the intensity of one component versus another (also known as ratios) can affect how a mix turns out. Too much Androstenone may overpower the softer pheromones in the mix and steer it towards a mix that generates a darker aura and effects. Too much Alpha Androstenol and people may not take you seriously because they’re laughing their heads off.
My symphonic mixes have individual component concentrations ranging from 0.5 mcg to up to 10 mcg. Even at such low levels, they do have a definite effect because you have to remember that it is the total effect of the mix that’s important rather than the individual components. 1 mcg of P74 may not seem like much, but it may be enough to help produce one building block of the mix, which when combined with all the other building blocks, produces a complete and potent symphonic mix.
Of course, the number of components also plays a significant part of the effectiveness of a mix, and adjustments to starting concentrations have to be made to compensate for them. Generally, the more components you have in a mix, the stronger your initial concentrations of your components have to be in order to reach the desired diluted strength in the mix. Using 15 mcg/spray concentration pheromones may be good for a 5-10 component symphonic mix, but when you get up to 20 or even 30 components, you will probably need starting concentrations up in the range of 50-75 mcg/spray.
My most complex symphonic mixes have up to 36 components, and my starting concentrations tend to be in the 50 mcg/spray range. Of course, it generally takes more than 45 minutes to make a batch, but any good potion maker will invest the time needed for the perfect brew! 
I’ve had my share of bad mixes to go with the good, but when they do work, the effects of some of these mega-mixes are just insane! 