Speaker crossover mod. Your advice?


I'm considering modding the crossovers of my Focal 1027s. Specifically, I am thinking about replacing the capacitor associated with the tweeter. I have received some helpful advice from another A'gon member who has done a similar mod to his crossovers (on a different model speaker from the same manufacturer).

I would greatly appreciate any suggestions from folks who have experience with this sort of thing. In particular, what sort of improvements can be achieved with this kind of mod? Any thoughts on which caps to use? Any common mistakes I should avoid? Is the whole thing a bad idea?

Thanks for your input.

Bryon
bryoncunningham
Thanks to all for the valuable input.

John - No sweat. I was about to send them to you when I saw your last post.

RE: Outboard crossover. Unfortunately, that's not in the cards. The room is not dedicated. Plus wife, pets, kids, etc.

RE: The size of the new caps. I was hoping to have the new caps "float" off the board a little, as in the following sketch:

FLOATING CAP

At least two problems that would need to be overcome in order to make this work:

1. Finding a cap with leads that are long enough to reach the board.
2. Finding a way to stabilize the cap.

Thoughts?

Bryon
Bryon--of course you're free to take this advice--or not--as you wish, but--
1. Stay away from Clarity Caps. That's what I removed from my Avanti tweeter filters. 'Clarity' my a...er...eye. I've been playing with caps for about 40 years. The SoniCap Gen.1 is the overall-best-sounding affordable cap there is.
2. Build the correct values with 2 caps. I believe you'll be thrilled with the results of using SoniCap Gen.1s paralleled with MultiCap RTXs, or, if you choose to afford them, SoniCap Platinums. The higher proportion of higher-quality cap, the cleaner/quicker/smoother the sound will be; I learned that dramatically in my TWO upgrades of tweeter caps.
3. Piggyback the 2 caps. If the larger of the 2 caps won't fit on the board, put the smaller on the board with the larger above it. I use 3M double-side self-adhesive foam tape. That plus the leads will hold the caps in place forever.
4. Replace the resistors in series with Mills MRA-12s, noninductive wirewounds.
5. Unless it takes hours to get to the x-over boards, do your upgrades in stages, with the tweeter section first.

The new caps in my x-overs made the treble so much better sounding that I now listen at around 5dB higher treble levels. You can tweek your treble balance by changing the value of R1.
.
Rx...

In order of importance...

Change L6 to aircore inductor $$$$$$$$$$
Change L3 to aircore inductor $$$$
Change L1 to aircore inductor $$
Change C3 to whatever suits your fancy
Change C1 to whatever suits your fancy
Hi Jeffrey - Your advice is greatly appreciated.

RE: SoniCaps Gen 1 caps. They have a 3.6uF cap and a 6.8uF cap, but both are only 200V, whereas the stock Focal caps are 250V. So I assume that's not going to work.

RE: SoniCap Platinum caps. They don't come in the correct uF values, nor do I see any combination of 2 caps that sum to the correct values. Not to mention, they are, to use your phrase, more than I choose to afford. :-) I was hoping to do the whole project for $300-$500, so I need to find caps in the $100 range or so.

RE: MultiCaps RTX caps. Again, I don't see the correct values, nor do I see any combinations of 2 caps that sum to the correct values. Also, they tend to be 200V like the SoniCaps.

Hence the search for caps continues...

RE: Mills MRA-12 resistors. This is a stupid question, but I assume that replacing the stock 7 watt resistor with a 12 watt resistor is fine, provided that they have the same ohms rating (of 5.6). Is that correct?

Bryon
Jeffreybehr, have you tried Clarity's MR caps? The rest of Clarity's lines are mediocre in comparison. And as much as I like Sonic Caps, there is absolutely no comparison between Sonic Cap Gen I's and MR's.

Bryon, floating caps is fine as long as the leads are protected with shrink wrap, etc... The leads on MR's are generally pretty long.