Speaker crossover mod. Your advice?

Byron,

There is another thread on Audiogon which might be of interest to you, "Capacitor log Mundorf Silver in Oil." It's a long thread but it logs the journey of several members who ended up with Duelund Cast crossover components. Those are very expensive components and I am not recommending them for your project just simply because for your crossover the cost would be huge. However, that thread does contain a lot of their impressions of other components they tried along the way.

I was going to suggest Mundorf Supreme as a good capacitor, but upon reading the large values you have in your speaker, I'm not sure what to recommend.

I am doing another speaker project and plan to use Clarity MR caps, Duelund Cast resistors, and North Creek 10awg or 12awg inductors, but I don't have nearly as many components as you, nor such high values.

What are you planning to do with the inductors, and are you going outboard with your crossover?

John

One more comment though, after reading your cap values again it is the woofer values that are the really big ones. Maybe it would be okay to just replace the midrange and tweeter caps as it's the inductors that would play the more important role with the woofer. Others on this or the other thread should be able to provide you with a more solid recommendation however.

Bryon,

I had missed your crossover pictures and apologize for my oversight. Magfan is absolutely right, there's certainly not going to be room on that board for any of the caps I've been discussing, and most likely not in the speaker enclosure either as he also mentioned.

If you do go outboard with your crossover, Google "inductor-coil-crosstalk-basics". There's also a good picture on the Parts-Express board showing good and bad inductor orientations.

John

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.

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

Bryon,

I don't have any experience with mixing caps from different brands. However, there's a lot of information in that Mundorf thread I mentioned. Those guys talk about mixing caps of different brands.

On 11/29/10 Undertow talks about his cap mix ratio a bit, but also mentions that there is no golden rule-of-thumb ratio.

On 2/1/11 Undertow responded to one of my questions, “I have used the Duelund, Clarity combo, but found that 100% Duelund or Clarity were better in my case overall. As for the bypass with the Silver oils and the Clarity MR's that is the best mid cost combo yet I have heard consistently, and very organic with good dynamics never any edge.” Also on that same date Face said that his experience was consistent with Undertow's.

My first choice in the various components we are talking about (capacitors, resistors, inductors) is Duelund. I used a Duelund VSF copper capacitor in my previous speaker project and loved it. The guys on the other thread have pretty much gone 100% Duelund CAST components, which is the blue riband of this arena. However, on my current project I don't have the budget to go with Duelund VSF copper, much less CAST. My goal with this project was to find the capacitor that those guys really liked before they went Duelund CAST, and that seemed to be the Clarity MR, so that's what I am going to try this time around. I also have access to a lot of tubes and will fine tune my system further once the crossover is in place.

I'm taking my crossover outboard this time and plan to use all Clarity MR caps and Duelund Cast resistors. I haven't decided on the inductors yet.

If you can get Clarity to build you a 3.6micF cap for you, I would do that and not worry about mixing caps.

Regardless of the caps you choose, I would recommend that you change out the resistors too and go with the Duelund Cast. If you don't have room for the Duelunds, I have used Mundorf M-Resist and thought they were fine.

Just another thought, if you have room for Duelund caps, I would not hesitate to go that route. CAST is the ultimate, but don't hesitate to use VSF. Write Frederik Carøe, he owns Duelund, and tell him that you need a 3.6micF cap and they will make it for you. Basically they make everything custom anyway, so it's no big deal. If you order it through PartsConnexion he'll just ask you to make sure they make a note on the order of the value you want. They may be able to adjust the size of the cap to fit in your space – and the same applies to the resistor, they'll make it shorter than their standard 5-inches if you require it.

John

Bryon,

I just want to add that I respect Face's experience and would heed his advice.

John

Bryon,

The size of the capacitor does not indicate its capacitance. You can get a meter from Sears for about $25 that will let you measure capacitance. That way you can be confident when you place your order.