DIY Replacing Components in Crossovers

This project you have in mind is one of the most cost-effective and rewarding of all the mods or upgrades you could do. The way you are talking is exactly the way to do it. Don't try and reinvent the wheel. Designing a crossover is very technical and very difficult, especially trying to improve on an already professional design.

Most all of the problems people have are due to changing values. The value of caps and inductors affects crossover points, changes the frequency each driver gets, and messes with the sound. Resistors are like volume controls used to turn the volume down on drivers that would other wise be too loud. Almost all the mistakes you hear about are people messing with these values. So measure and be very careful not to change any values.

Audiophiles love to talk about caps. In reality resistors and inductors are equally important. The better ones don't "change" the sound so much as reveal more of what already is there. As you go better and better (read, more expensive) they remove or distort less and less and so you get more and more of what was already there. This is for caps, resistors, and inductors. 

Here is a good source for many different caps -

Here's one for resistors -

 This isn't really comparative but gives some good info on inductors. Coils make a huge difference!

https://www.erseaudio.com/Products/FoilQCoils

Also if you look at my system page towards the end there are pictures of the crossover upgrade done on my Moab speakers. Several of us on the FB Owner's Group have done projects like this, to varying degrees. Everyone so far extremely happy. You will learn a lot. Good luck!

Great advice guys. Very much appreciated!

MC thanks for the links. I'll give that a study this evening. I wouldn't mind playing around with the inductors as well but I didn't see any values for those on the existing parts. I was simply going to do a one for one replacement for the parts that have their values identified and stick with it for the new part. Yeah, modifying the design of a crossover is way way out of my league. BTW your Melody integrated looks an awful lot like my old Mystery IA21 integrated amplifier I used to have. Wish I never got rid of it. 

Erik, based on your comments it sounds like even replacing parts one for one may be an issue for caps in parallel with the drivers. Your description of verifying the values with a computer program makes my palms sweat a little.

Thanks again guys.

I rebuilt my crossovers with path audio resistors, mundorf silver gold oil caps, jupiter copper foil caps, with duelund silver foil bypass caps on all capacitor !!. the difference was night and day, but it also was a lot of money for the parts. look up humble homemade hifi, you can read all about the difference in capacitors and how they sound. path audio resistors are the best to use sound and size wise.I moved my crossovers to the outside on the back of the speaker in an oak box I built with a plexi glass door, so I can make changes anytime I want without going inside the speaker.

The smart way to go about it, get some high end Deulund bypass caps. Not cheap, but at .01uf you can simply add one to any existing cap and hear improvement without having to buy a cap in some value you might never be able to use anywhere else. Filter caps at .01uf can be used lots of places. The value is too low to affect the circuit, but just enough to smooth and provide rich natural detail.

Next would be resistors. Almost all are the cheap white sand power resistors. Almost anything will be better. Power makes resistors hot, heat increases resistance, resistance lowers voltage. This all happens very fast. Fast enough to affect dynamics. So use quality resistors and don’t hot glue them like everyone does but instead mount them with air flow all around.

Inductors usually have to be measured. This calls for an LCR meter. But you don’t have to measure or even replace inductors to improve them. An inductor is a coil of wire. Coils of wire produce magnetic fields. Magnetic fields interact with wires. To minimize this we place inductors at right angles to each other. At least that is what we’re supposed to do. If your speaker has more than one inductor and they are hot glued flat to the board then you can improve the sound simply by moving one to be at right angles to the other.

Also inductors work slightly better with the signal going from the inside to the outside. Not a huge difference but it is there. If it is easy to reverse the leads then go for it. Don’t cost nothin’.

In case you are keeping score that is 3 crossover upgrades I have given you that cost nothing. And we haven’t even gotten to the rubber bands.

Grannyring, bought a number of Duelund CAST PIO caps as part of a crossover upgrade. These caps are out of stock most places.

So for the midrange section, where I need 13.0uF, I bought 8.2 + 4.7 + 0.1 for one speaker and 8.2 + 3.3 + 1.5 for the other speaker.

The Duelund CAST PIO 100 Vdc caps are disk shaped, with greater uF values (like 8.2 in my case) having modestly greater height or thickness than lesser values like 4.7uF, but the roughly 7” diameter is the same for the two values just mentioned and I think for the 3.3 as well.

It seems to me that the only real option is to put the caps on top on each other, like layers in a layer cake. The leads come out of the top of the caps, close to the outside of the disk-shaped caps. So I would need some sort of spacers so that the top caps aren’t resting on the leads of the cap underneath.

I will also need a way to secure the caps to the board. I don’t like the idea of plastic ties per se, and might be more interested in a bolt screwed through the board with the thread end toward the ceiling, and some sort of clip. Several bolts / clips per cap. I may end up having to settle for plastic ties, though.

I won’t have this problem for the woofer section, where I will be using Auricap XO+ (a brand new ‘uptier’ from the XO which HHHiFi rated 11 vs 15 for the Duelunds that I selected for the other sections), or one of the tweeter caps. The other tweeter cap is 5.6 + 0.22 + 0.22 to get to close to 6.0, so I think only the 13.0 need in the midrange section needs a solution.

Any thoughts on how to best put 8.2 + 4.7 + 0.1 on the one board and 8.2 + 3.3 + 1.5 on the other, and whether stacking the discs on top of one another might cause performance issues due to the magnetic fields of each etc?