Effects of capacitors in parallel

[ted01]

It has been suggested that I use two caps in parallel to achieve the values I need as I rebuild a xover network for the 4412's. Are there electrical or audible differences when doing this?

Thanks!
ted

[Robh3606]

No

Rob

[ted01]

Well, Robh3606. Sure wish you weren't so verbose!!

Cool. I'll be ordering what I need then.

Thanks,
ted

[Wagner]

Well, Robh3606. Sure wish you weren't so verbose!!

Cool. I'll be ordering what I need then.

Thanks,
ted

Try doing a search on the subject, you may be surprised to learn that you are not the first to ask this question.
It is dealt with in extreme detail here at this site I have learned (as a result of using the "search" feature).
I have also learned the very brief time I've been here (from lurking) that questions that have been asked a 100 times or more are generally ignored, or draw a short response at best.
Lansing Heritage is for serious enthusiasts, or rather encourages, and those who wish to be. Plenty of room on board for the novice, (I fall in that category), but not into wasting a lot of breath and bandwidth, so it seems.
If an honest attempt to answer a question on one's own devices proves fruitless, and you reference what you've tried, you will be amazed at how many people will take time to help you.
Try asking questions as if you were at the library; ask for directions to a particular section or topic. The archives here is extensive (as I am learning). Folks will help you navigate it.
They're not into internet forum "noise" here. At least not the important players.
That's my take on things.
Have fun,
Thomas

[Allanvh5150]

There is one major difference when placing capacitors in parallel. Capacitors have a certain amount of inductance. For example, 2 x 3uf caps in parallel have less induntance than a 6uf cap. This is the main reason that bypass caps are used. A small cap of say 0.1uf has very little inductance and will basicaly cancel the inductance of a larger cap without adding significant capacitance to the network.

Allan.

[Robh3606]

Well, Robh3606. Sure wish you weren't so verbose!!

Hello Ted

It's a simple answer to a simple question. By all means use the search function but be careful not to get lost in the conversations and opinions. There is as much as there are truths. If you look at many of the JBL schematics, 4345 as an example, you will see multiple caps used to get larger values. It's a very common practice.

http://www.jblproservice.com/pdf/Net...%20Network.pdf

Rob

[ted01]

Rob (and anyone else),

One last question... Is there any advantage in going with, say two 6.8 uF rather than, say, 12 and a 2 uF to get to 14 uF? In other words, should the caps in parallel be close to each other in value, or can any combination that adds up be used?

Thanks for the help.
ted

[jcrobso]

If this is for the high frequency section use a .1 uf in parallel is recommended.

[grumpy]

For combining bulk capacitance values (as opposed to whatever you'd like
to use if trying out the bypass technique), I'd worry more about matching the
capacitor construction methods and materials, and address physical mounting
or space issues... rather than splitting the value exactly in half if it's not
convenient to do so.

[ted01]

Thanks for the help everyone. Jcrobso, the schematic calls for a .01 uF cap for the bypass on all caps, not just the HF section. That is what is currently installed on all four of the xovers now (factory originals, I suspect). Pro's/Con's of using the .1 uF you suggested?

ted

[jcrobso]

Thanks for the help everyone. Jcrobso, the schematic calls for a .01 uF cap for the bypass on all caps, not just the HF section. That is what is currently installed on all four of the xovers now (factory originals, I suspect). Pro's/Con's of using the .1 uF you suggested?

ted

There was a rule of thumb, make 10% of the total value of the capacitance for the bypass cap. john

[grumpy]

My understanding is that the utilized JBL network values were settled on after
experienced listener review, and in combination of types (perhaps on-hand)
and values that produced a desired or "better" result. If that's incorrect,
someone pull the flush handle.

[Robh3606]

There was a rule of thumb, make 10% of the total value of the capacitance for the bypass cap.

Just curious but where did that come from?? It's not something JBL has ever done. They have used the .01uF across the board independent of the main capacitor values.

Rob

[jcrobso]

Just curious but where did that come from?? It's not something JBL has ever done. They have used the .01uF across the board independent of the main capacitor values.

Rob

I'm guessing I first read about this in a Audio Magazine from about 40 years ago, but now days we use .01uf in general. About 42 years ago Audio Magazine published an built it yourself active crossover article also.

[4313B]

There were a couple other places that published info along those lines. Here is one I remember from years ago:

Capacitor FAQS

Bypassing

The info that I posted on this website still stands:

Bypassed and Biased Capacitors