Speaker crossover mod. Your advice?

Bryon, judging by the photos you linked to in your first post dated 2-12-11, it appears that the circuit connections are on a layer or layers internal to the board. Unless you can see exactly where they are by shining a light through the board, drilling holes would therefore be a no-no.

Best regards,
-- Al

Thanks for the warning, Al. That's just the kind of rookie mistake I was hoping to avoid.

RE: The lack of room on the circuit board for the new caps...

Another poster suggested (in private email) that I build a small platform to go above the existing crossover board and attach the platform to the circuit board with wood blocks that are glued to the spaces created by the removal of the old caps. Then I can mount the new caps to the second platform, which would provide plenty of room for some of these big boys. I'm planning on using this approach.

RE: Which caps to use...

Obviously, folks have strong feelings about caps. I don't want to start a war, but I do want to elicit one last piece of advice about which caps to go with. Here is what I'm hoping to achieve: SMOOTHER treble. I would like to try to remove the last bit of grain and glare from the top end. In light of that...

-After reading about caps in other threads, the Duelunds sound perfect. But they are too much of a budget buster. :-(

-I have seen the Mundorf silver/oil caps described several times as "smooth." Hence my interest in them.

-I have seen the Clarity MR caps described as "neutral" and "transparent." Those characteristics are great, but may or may not involve greater "smoothness," which is the principal reason why I am changing the caps.

Thanks for any guidance.

Bryon

Listen to Al.

The advantage of multiple caps in parallel? Lower ESR.

The DIS advantage? Lots of space. And, since caps are not 'pure' capacitance, they also have an inductive AND resistive component. Careful consideration must be given such changes.

Changing the caps without addressing the inductor is only 1/2 the job. if that.

Caps are also considered microphonic, which is a good reason to get the crossover OUT of the enclosure, not to mention the increased volume taken up the the caps could conceivably change the bass tuning.

Get an integrated plan together.

I have read a large fraction of the Mundorf s/o thread, the entire humblehomemadehifi shootout, and several others threads devoted to caps and crossover mods. I now have a plan...

1. Tweeter cap C1. Replace with a single 3.6uF ClarityCap MR.
2. Tweeter cap C2. Replace with a single 6.8uf Mundorf silver/oil.
3. Tweeter resistor R1. Replace with a Duelund CAST resistor.

My reasoning, FWIW...

--I would like to begin with the tweeter only. I very well may replace other crossover components in the future, but as a beginner, I would like to approach this in steps. Hence I will not be replacing any inductors at this time.

--I wanted to avoid bypassing caps, since several people warn about possible smearing effects. Hence each cap will be replaced with a single cap of identical value.

--I want to try to make the treble smoother and more liquid. Hence the choice of the Mundorf s/o for the 6.8uF cap. But the Mundorf s/o is not available in 3.6uF. Hence the choice of the ClarityCap MR for that position. I know that some folks discourage mixing caps from different manufacturers, but others report good results with that approach. So I will give it a try. My hope is that the liquidity of the Mundorf s/o and the transparency of the Clarity MR will combine to give me a pleasing balance of both characteristics.

--I cannot afford Duelund caps at the moment.

--I cannot go external.

That's the plan.

Bryon

E-mail Jeffrey Glowacki of Sonic Craft for advice. He knows more about crossover parts than ALL of us put together.

mail@soniccraft.com
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