the worth of a cap bypass (or cascade)

Could anybody comment on the worth of making a bypass or cascade cap for the high pass XO? I'm thinking of it, but it can get pretty expensive so I'd like to get people's comments first.

What I'm thinking of doing is replacing a 10uF 400vdc cap by the following cascade:

6.2uF 250 vdc
2.7uF 250 vdc
1.0uF 400 vdc
0.1uF 630 vdc

toughts? comments? suggestions?


2005-04-29 11:43 pm
hi Sberube,

I would suggest you try your combination with less expensive caps (like Daytons available from before you sink a lot of money into high-end parts.

I tried the essentially the same thing, mounting five caps on a circuit board with a bus bar that allowed me to alligator clip various combinations quickly. I found that a 0.1uF brightened the sound quite noticeably, giving imho a glaring edge to everything. I didn't like the effect. With a different amp/speaker/room combination, it might work.

Good luck,
I agree with Lensi. A small bypass cap can cause HF to get ahead of lower frequencies, leading to sibilance and/or excessively bright sound. I tried Solens with bypass caps including Solen, Auricap, Multicap, and Jensen oil. I did find the Auricaps worked better than the Solens alone, but I had to try various combos to arrive at an acceptable recipe.

I recommend a single good cap and forget the bypass if at all possible. I'd even go so far as to source an offspec pair to avoid paralled caps (e.g. my crossovers call for 10.7 uF. I was told by Audience that they could provide this value in an Auricap).

I also don't like using similar-sized caps as opposed to a single cap. I find it affects the coherence of the sound.