crossover question

[Rodtay]

in a crossover, does 0.1 uF make a big difference in the sound. Let's say we need a value of 11.6 uF and you can only come up with 11.5 uF, would this be a big problem? Also, would switching from metallized polypropylene cap to a non-polarized electrolic cap make a difference in the sound?

[Jay]

Depends on the circuit, 100n may make a big difference but mostly NOT. Audio system performance is mainly determined by speaker performance. Speaker performance is mostly determined by it's crossovers. Not a crossover with expensive components but a crossover with CORRECT (or magical) design (and the enclosure). This is true because especially non-expensive drivers has so many anomalies (and of course the weakest link in the audio chain) that you have to solve with complex crossovers. A crossovers with the same set of drivers may create a $2000 or $100 speaker!

In a crossover, it doesn't mean that it doesn't make a big difference just because you cannot hear a difference in sound. Whereever it is in the crossover circuit, I doubt you can hear a difference by reducing by 100n (because you will have to check the sound in every single frequencies, not to mention the other many related effects which are more important)

Even different cap brands have their own characters. The most important cap is the one filtering (in series with) the tweeter. Use any MKP as a standard (Electrolitic for coupling, paralell to the woofer, if it has to be a big value). In my experience, MKP has the biggest Performance-To-Price ratio (e.g. General Electric). I don't trust expensive MKP but oilcap or paper or paper in oil (in this position). I always put oilcaps at least in parallel with other caps (MKP) in the audio path.

[Rodtay]

thank you for your input. It has been helpful in helping me find components for my crossover easier. This is for my first project so I hope it comes out good.

[Ron E]

The difference between 11.5 and 11.6 is less than 1% Your typical capacitor has a tolerance of 5%.

Modeling a typical circuit, changes of even 10% are very subtle. It is fine to select values for crossovers within this 10% window.

It is much more important that the components match from side to side within ~5% or so. Side to side matching affects imaging.

Drivers can also vary, so some mfg's measure every speaker and adjust the crossovers by paralleling caps and unwinding inductors so that all meet a target +/-...