Crossover cap questions.

[Jidis]

Hi again,

I had a few more questions on caps for passive crossovers:

- Is there any major downside to running a network of parallel or series caps to get to a specific value rather than a single cap? If not, does that hold true regardless of how many you had to use (for instance, five small film caps of different values in parallel)?

- How much worse off are you for using a large value NP electrolytic to make up the bulk of the capacitance and then a small value non-electro in parallel?

- < less important question for less important crossovers > Relatively old hi-pass caps test within range on an LCR meter, and series resistance looks OK on an ESR meter. Do you assume that those caps are in good working order, and if not, under what conditions will they show their age? I've got a scope and a frequency generator and would love to actually see whatever these distortions are that I'm trying to avoid.

Much Thanks!

George

[tinitus]

ONE cap sounds better, always

If in need of bigger one than available, like say 150uf, the TWO filmcaps100uf+50uf is better than a single 150uf bipolar
Whether 75uf+75uf film cap is even better, I dont know, but some will claim that, other the opposite
But ONE is better, so....

But I dont say that nothing else wont work
Design is the most important of all
Then comes xover
Next is drivers
Then the built
And so forth
Xover components is pretty much last on the long list
And how you use them is even more important than the component itself

[Jidis]

Originally Posted by tinitus

ONE cap sounds better, always

Damn. Not what I wanted to hear.

I'll have to stock up on some larger values from somewhere. I found some recommendations for Vishay (MKT maybe) and ordered a bunch of them, but there was a minimum of ten each, so I thought I would be better off going with 1 and 1.5uF, then a couple sub .5 values to fine tune. To get higher values, I'd have to order a whole batch (15 or 20 bucks worth) of something just for a couple caps and I still couldn't get the exact values in one unit. None of my target values are large. I think 5.5uF is the highest one right now.

Thanks!

George

PS- Still wondering on the second two questions if anyone knows.

<edit>- (regarding that NP electro/film combo question) If it matters much, those higher valued ones would be serving mid/low frequency duty. My tweeter stuff looks like it's all going to be <2uF.

[tinitus]

Originally Posted by Jidis

then a couple sub .5 values to fine tune.

None of my target values are large.
5.5uF is the highest one right now.

Oh
with smaller values I never care too much about the exact value, but rather prefer a single cap, the closest standard value
Though one might need to determine whether going to the lower closest or higher closest value, if difference is close to the same
My, thats tricky in foreign language

Mind you, personally I have no doubt what I prefer
To me, multiple caps have more negative sideeffects than just using a standard value being slightly off value
You or others may have different experience/opinion
In time you may not think much about it either way, but will get accustomed to the sound you hear

[pheonix358]

I will have to disagree on this. Multiple small caps will decrease the impedance and inductance of the caps and this is a good thing. I have a personnal preference for only using one value when // caps. That is unless the other cap is a bypass. Using multiple caps is fine and should lead to improvements.

Terry

[Face]

If possible, you shouldn't parallel caps in series with your tweeter. Otherwise, don't sweat it.

[pheonix358]

Originally Posted by Face

If possible, you shouldn't parallel caps in series with your tweeter. Otherwise, don't sweat it.

Why, ok it shouldn't come up very often, the values are small anyway, but why not. You decrease both inductance and resistance.

[Face]

In my setup, I've found that a single cap always imaged better, paralleled caps always caused some image blur. Your mileage may vary.

[pheonix358]

Originally Posted by Face

In my setup, I've found that a single cap always imaged better, paralleled caps always caused some image blur. Your mileage may vary.

I agree in absolute terms if the caps are of different values, different values tend to cause smear, otherwise there may be advantages. Try both and see. It is a small point since I have seldom tried it.

Terry

[Pit Hinder]

The main problem, single or parallel, is believing the value printed on the cap - channel differences cause the "smear".

If you are on a tight budget, ie no measuring tools and cheap caps with larger tolerances, switching in parallel is your only hope - if you are lucky, tolerances will cancel each other to some degree.