Mounting crossover to rear of driver

[lucadelcarlo]

In terms of a negative impact on sound, I recall that this is generally frowned upon for good reasons, but please remind me a) why one would not want to do this, and b) if it has to be done, how can it best be accomplished with the least negative impact on sound?

I know that there've been a number of coaxial drivers produced by manufactures with a x-over on board (not just a simple high pass), one by Tangband comes to mind, but this is generally never seen in high-end designs.

What do I need to be aware of in my selection of x-over parts and their layout in this situation, if it has to be done? The speaker and its enclosure in my scenario are both small and the enclosure does not readily provide a convenient interior surface to mount the x-over on. It would be convenient to mound on the backside of the driver, if negative effects can be managed.

[JMB]

Two things that come to mind would be vibration and inductance. These would impact the durability of the crossover and would likely influence frequency response, respectively.

[AllenB]

One obvious issue would be if you were to use an inductor with an iron core. The driver's magnet may potentially saturate the core. Different types of components in different parts of a crossover might suffer less or more.

Then there is the vibration. Some components will physically distort which might change their behaviour as they vibrate.

And thirdly vibration of the whole component would move it through the magnetic field producing flux and inducing current in some components.

Not that these things are never an issue elsewhere, of course, and not that it is necessarily going to be a problem. It's not unusual to see aluminium electrolytics hot melt glued to magnets with no particular stand out issues.