Passive Crossover Design

Andy Kos wrote: Interesting comparison, but hardly appropriate in my opinion in this instance. If it were a 2khz crossover going between 12" and 1" I would agree it needs a bit more effort to get right, but even then, if it's not perfect, it will still work. Here we are looking at a 200Hz crossover point, it's hardly the most difficult crossover point to get two drivers that are reasonably well behaved either side, and although the result of a standard crossover here may not be 'perfect' it would be perfectly acceptable. The main issue is getting components to handle the power appropriately and that arent too lossy, poor components are more likely to cause problem than  missing out a zobel network.

MarjanM wrote: Andy Kos wrote: Interesting comparison, but hardly appropriate in my opinion in this instance. If it were a 2khz crossover going between 12" and 1" I would agree it needs a bit more effort to get right, but even then, if it's not perfect, it will still work. Here we are looking at a 200Hz crossover point, it's hardly the most difficult crossover point to get two drivers that are reasonably well behaved either side, and although the result of a standard crossover here may not be 'perfect' it would be perfectly acceptable. The main issue is getting components to handle the power appropriately and that arent too lossy, poor components are more likely to cause problem than  missing out a zobel network. Ok, let me explain some other problems here. Usually the lf driver here will probably be some sort of 15 inch driver and the mid driver most probably a 8 inch driver.  Now, if the 8 inch driver is a dedicated mid range driver, it should be about 3-6db more sensitive then the lf driver. Making an attenuation for a driver that will work at like 200-300W means that you need to burn about 100-150W and transfer that in to a heat. That is not a very good idea isnt it? Not that it can not be done, but again, it is on all different level type of work. Not something a newbie can do.

Edited by Andy Kos - 27 November 2016 at 7:12pm

Some good points above, but I still maintain that 200Hz is too low a frequency for a successful homebrew passive crossover as a newbie project.

Components to handle the power properly will be very expensive, especially when considering that you need a range of different values for experimentation.

There's nothing to stop you trying and I don't want to discourage experimentation, but it's useful to be aware of the limitiations. The biggest problem is finding suitable inductors.

If I wanted to gain some experience, I would start with a mid-to-high crossover. The parts are smaller, cheaper, and widely available.

For two crossovers it will take (according his calculations) 4 coils of 9mH each.

Scroll back 2 pages and see my first reply.

It does also depend on power handling requirement, if this is a hi-fi project it could potentially be achieved with smaller/cheaper inductors. If it's for higher power use, it's cheaper to go active.