Speaker crossover mod. Your advice?

Thanks, Jeff. Just discovered this: "J" indicates a 5% tolerance, according to capacitor codes. In light of this...

Is it a safe assumption that the 3.6 and 6.8 caps are 3.6µF and 6.8µF? Are those typical values for caps associated with tweeters?

Also, finding a 3.6µF cap has been a little difficult. The caps I've found so far from various manufacturers are either 3.3µF or 3.9µF. I assume that using a different value will change the frequency of the high pass filter. Is that a bad idea? Or is the difference - .3µF - small enough to be ignored? Should I just keep searching for a 3.6µF cap?

Anyone?

Hi Bryon,

Yes, those are undoubtedly 3.6uF and 6.8uF. FWIW, though, I would not feel comfortable introducing an 8.3% error into the nominal value of the 3.6uF cap, especially in a crossover network that is designed, as this one appears to be, to have sharp slopes.

It might prove helpful to keep in mind that using two caps in parallel, where their individual capacitances sum to 3.6, would be a way of achieving the correct value. I believe 1.8uF is a standard value.

Best regards,
-- Al

Bryon,

I don't have the experience or confidence to change capacitor values, but that is an 8% difference you are considering. The Mundorf M-Cap Supreme line has 2% tolerance. You can read some reviews about caps at humblehomemadehifi, and also Google the Tempo Electric reviews.

I went to the Madisound website and looked at the Solen Fast Caps and didn't see a 3.6micF value. I assume that's what's in your speakers, but maybe Focal had them custom made, and if that's the case, they certainly must have considered that the best value for that tweeter. I wouldn't stray too far.

Here's a couple of options for you:

Option (1): M-Cap Supreme:

- two 1.8micF caps in parallel to give an equivalent 3.6micF value.

- single 6.8micF.

Option (2): Clarity MR w/ Mundorf Silver/Oil bypass caps:

- One Clarity MR 3.3micF with one Mundorf 0.36 S/O cap in parallel to give 3.66micF... (1.7%) but maybe that's okay, I don't know.

- One Clarity MR 6.2micF + 0.68micF S/O = 6.88micF (1.2% off).

I think the M-Cap Supreme would be an upgrade for you and you can maintain your exact values, but if the 1.7% and 1.2% differences are insignificant, some of the members on the other thread I referenced like the MR - S/O combination at lot, but others also report that they get the best results from having a single brand cap in the crossover.

If it were me, I'd do the M-Cap Supreme, it's a safe choice, maintains your exact values, and is a simpler installation.

As for the resistors, on the PartsConnexion website they have a 5.6ohm, 10W Duelund Cast resistor listed. Other than that, I'd go with the Mundorf resistor I guess.

John

P.S.: If you wanted to go all Clarity MR, you could do a 3.3 + 0.36 = 3.66, and then a single 6.8MR.

Thanks, Al. I assumed the caps were uF, even though they are not marked as such. As this is my first attempt at a mod, I don't want to make a rookie mistake.

You are right that 1.8uF is a standard value, so connecting two caps in parallel might be an option. Do you know whether two caps can be connected in parallel to the crossover board, in light of the fact that the board has only one pair of holes for the stock 3.6uF cap? Do I simply place the leads from the two new caps into the same holes, so that each hole has two leads?

Bryon,

I was just reading the white paper linked on the Madisound webstite for the Clarity MR caps. It mentioned that intermediate values are available upon request. You might be able to order a 3.6micF from them. That may be the same case for the Mundorf M-Cap Supreme too, but between those two, I'd go with the MR.

You can ask Madisound or PartsConnexion about it. Also, you might send Mundorf and Clarity an email and see what they say. But if you can get a 3.6micF cap made, that would be the way to go.

John

John