Parallel and series components in xover

[andy2]

In a xover, would the parallel or series components have more impact on the overall sound?

I am asking because if I were mix low and high quality parts to save cost, should I use high quality part for series components rather than parallel components? Or should it be the other way around?

[BillFitzmaurice]

Make your series components, those that signal passes through on the way to a driver, high quality, while parallel components that shunt to ground need not be top grade.

[Pan]

There is no difference whatsoever in the series or paralell connection, both affects the signal to the driver terminals as much.

/Peter

[andy2]

Speaker makers often say that their xovers have premium parts in the critical path. So what would determine a specific components in the critical path?

Is it just merely parallel or series or some other factors?

[BillFitzmaurice]

There is no difference whatsoever in the series or paralell connection, both affects the signal to the driver terminals as much.

Not so. In the signal path a low Re inductor is usually a good idea to prevent insertion loss, but with a shunt inductor in the HP section having a low Re isn't particularly useful. Conversely, using high quaility polys in the signal path of the HP section is recommended, but signals in the LP section being shunted to ground don't require the same attention or expense.

[Pan]

Kind of agree, sure, there are choices and compromises to be made often. My point was just about the widespread misconception that non-linearitys and resonances in paralell components does not matter... which they must do since everything in the circuit will affect the voltage on the driver terminals.

Then as you say, the demand for top notch performance depends on where in the circtuits the component is working.. impedances and so on.

/Peter

[PaleRider]

Originally posted by Pan
There is no difference whatsoever in the series or paralell connection, both affects the signal to the driver terminals as much.

/Peter

Exactly. But there`s another side of this too; filters powerhandling-capacity. Instead of using just one single resistor; use 3-5 or more in paralell (like 4x32Ohm=8ohm) and never use electrolyts, they`re just too poor. In my filters I also put like 3 caps in paralell to reduce filterresistanse, but only at the same size(for summary) and only for lower frequenses, not tweeters.

Personally I won`t ever use just one single component in paralell cause it makes the amp "see" itself or as i call it "a frekvensrelative shortcut". But if two or more compoonents are used -(in serie), in paralel with the signal, the amp/signal doesn`t "shortcut" the same way. (see speaker-imp-curves)

- and not to forget; the purity of the signal is affected by every component, not only the ones in serie!

[AndrewJ]

Both series and shunt components affect the sound.
The notion that the shunt components don't matter as much because they are shunting the signal to ground is bogus.
It they are imperfect the signal components that are not shunted to ground will then appear at the driver and contribute to the sound. Additionally, since all networks higher than 1st order use the interaction between the series and shunt components to produce the required equalisation and roll-off, then it should be obvious that the shunt components play an equal role.
Now in the case of shunt inductors, it is often the case that they can have a higher loss resistance than series components, as the circuit sensitivity to the loss resistance, within the passband, is lower than that of the series inductor. Additionally, less power is typically dissipated in the shunt component. This allows one to use a lower cost inductor because less copper is used in the winding, but the quality of the component still should be as high.

Andrew