High value capacitors

[Scareurpasenger]

So, I am getting supplies together for a few new speakers but am trying to optimize performance and budget. Based on some reviews it looks like there may be some lower priced capacitors out there that seem to out perform for the price point. I just haven't seen anyone else mention these brands for use in their crossovers. In particular, Cornell Dubilier, Panasonic ezp-e and the JB capacitors jlx line. Does anyone here have any experience with these?

[Steve Manning]

So, I am getting supplies together for a few new speakers but am trying to optimize performance and budget. Based on some reviews it looks like there may be some lower priced capacitors out there that seem to out perform for the price point. I just haven't seen anyone else mention these brands for use in their crossovers. In particular, Cornell Dubilier, Panasonic ezp-e and the JB capacitors jlx line. Does anyone here have any experience with these?

Don't know if they are covered by Tony, but he reviews a bunch of different caps. http://www.humblehomemadehifi.com/Cap.html

[5th element]

Usually anything that's marketed as an industrial part, such as the Panasonic ezp-e, are going to offer better value than most 'for audio' parts. There's nothing special about audio except the 'special' pricing certain companies like to attach when they try and market parts as such.

Don't over spec either, some of these industrial parts have very high operating voltages and are completely unnecessary for almost all loudspeaker crossover use. You only buy a higher voltage part if you need it because otherwise it just costs more, takes up more space and comes with more parasitic losses.

A 100 watt/8ohm amplifier can put out ~40 volts DC when it fails. This isn't a situation you want to be faced with but you would want your tweeter capacitor to be safe under such a condition. And it will put out 28Vac.

A 200 watt/8 ohm amp will output ~60V DC when it fails and 42Vac under normal operation.

As you can see you don't really need particularly high operating voltages for crossover components.

Polypropylene has always been the go-to for high quality loudspeaker crossover parts, for good reason, it's one of the best dielectrics out there. But even for loudspeakers it tends to be overkill. Under detailed measurements polypropylene will show lower distortion than polyester, but polyester is still capable of distortion magnitudes below that of the speakers. We're talking 0.000x% distortion vs 0.0000x% distortion if my memory serves me well.

Polyester are available in a wide range of capacitances, are compact vs polypropylene, less expensive and come in a wide range of voltage ratings.

[JonMarsh]

There are many trade-offs for cost and size. Matt covers some very important points. However, even within the fold of "audio" capacitors, there are variations in build technique and results in some areas subjectively.

It's your usage case that should play a big factor in your final choice, as well as space and budget constraints.

Let's look at one of the types you mentioned- the Panasonic EZP-E series. BTW, in my day job, I play a high power, power conversion application engineer, so these are right down my ally of expertise (Senior Principal Engineer)

You mentioned high value, but did not quantify it- did you mean 20uf, 70uf, 100uF? or? (engineers like to be very specific... generally... my PhD engineering manager being one of the exceptions to that statement, unfortunately).

This series is designed for high power high voltage bus bypass applications, such as for motor inverter drives or solar inverters, or other high power SMPS applications. One problem with this series for audio is the tolerance- +/- 15%. That is really too much for a precision crossover application, where we would rather see 5% or less. For a zobel, it might be OK. DC voltage rating is 630V. That's good, IMO, because the thicker films and thicker metallization seem to have less issues with electrostatic vibration and physical resonance. a good "budget" audio cap following that are the Audyn Cap Plus 800V series. Premium audio capacitors go to a great degree of effort to suppress those electrostiction related phenomena, but it's not at all important for a bus bypass cap. If you're starting to get the impression it's all about the usage case, then you're getting warm...

Examples for audio caps include the Jantzen Superior Z series, the Clarity MR series, the Obligatto Gold series, etc. If you see the capacitor built with a metal or plastic tube as it's outside casing, then they're probably paying some attention to that.

Looking at higher value parts in the Panasonic EZP-E series, 60uF, 500VDC EZP-E50606MTA. This is a 10% tolerance part (better, not really good enough, though) It's 4 pin because by having input and output pins, they can minimize the series ESR for high frequency switching currents. Length is 41.5mm, height is 55mm (two inches) and width is 30mm. Price is $14.67 each, 10+ $13.95.
ESR is 3.9 mOhms, which is a good number. Typical audio caps I've measured are 5mOhm to 10mOhm. I don't think this makes any meaningful difference for crossover applications, but for high power SMPS switching it has a big influence on the peak ripple voltage for a given switching current.

Now, let's look at a similar "budget" audio cap, an Audyn Q4 68uF 400V MKP capacitor. 52mm diameter, 62mm length. A bit bigger, but it is also 5% tolerance. $17.70 each. 10+ price is $16.13.


So, is the non-audio cap a good deal? Well, I'll tell you, the way cap manufacturing works, what you'll usually find when you QA parts incoming is that the tolerance spread of the capacitors is pretty narrow. But what that means is that most of the caps are right near the bottom of the capacitance spec- that is, XX.X uF, - the tolerance value. So it if it is a 60uF rated cap, and the tolerance is 10%, they generally come in very close to 54-55uF. It's just economics and specmanship, and the reality of what is possible with precision manufacturing.

So, consider all these points carefully. I'd tend to recommend using Jantzen Cross cap or Solen or other "budget" film types if saving money is the key point of your agenda, and your sources and equipment don't really merit higher end components. But just to get the frequency response you expect out of a crossover, the tolerance must be 5% or less. most of my builds use 2% tolerance, and all parts are checked on a precision LCR meter before going on the board.

10% or 15% tolerance is not advised or recommended.

[5th element]

Come on Jon electrostatic and microphonic phenomena only have a tiny effect on phono preamps and that's when the caps are being smacked with a heavy object in a high gain, high impedance situation.

In a loudspeaker it's effect is going to be completely buried in the noise floor.

Of course you need to watch out for tolerances.

I wouldn't even use a film cap in a situation that needed a 68uF part.

I'd use one of those.

https://www.intertechnik.com/shop/cross-over-parts/capacitors/rough-foil/era681001_1768,en,606,46662

Unless I really needed something that could handle high voltages. Or was expected to last 20+ years.

[Scareurpasenger]

I should have been more specific. I was trying to make my money go further and not pay too much for marketing of the capacitor if there was a more general offering that produced a very good result. So my high , value it wasn’t the specification.

Although, the spec I am looking for is 50uf which can get very spendy. It is for a tweeter since that seems to matter.

[Evil Twin]

http://www.madisound.com/pdf/claritycap/MRWhitePaper.pdf

Not relevant to low frequency applications, but definitely relevant to midrange and treble applications.

[Scottg]

..It is for a tweeter since that seems to matter.

Depending on the tweeter and partnering electronics, yup. (..I'd argue though that 50uf for a tweeter "sounds" unusually low in freq., even for 4 ohms, unless it's meant for *correction. I could "see" it for a "FAST" design though.)

This is a good "building" cap (..a cap you add-to with more expensive caps for a particular sound) to get higher values:

https://www.madisoundspeakerstore.com/carli-capacitors/carli-mylar-20-mfd/

-it's good enough on it's own, and better with a good very small value bypass.


To get something more like an expensive sounding result typically starts requiring at least 1/3rd of the value of the total capacitance with that particular capacitor you like (..which is usually more expensive).


A budget option with a bit more "body" (a bit more "3D" image quality) would include the cap above +

https://www.digikey.com/products/en?mpart=SFS44T30J291B-00DU&v=338

And for some added clarity with a bypass:

https://www.tme.com/us/en-us/details/kfpm01-0.1u_600/audio-polypropylene-capacitors/miflex/kfpm01h410g/

*for correction I'd just use the Carli cap's (1 at 20 uf and 2 at 15 uf) with the tiny Vishay bypass:

https://www.partsconnexion.com/VISROD-72206.html

https://www.madisoundspeakerstore.com/carli-capacitors/carli-mylar-15-mfd/

[5th element]

Not to disbelieve the white paper and I studied at the acoustics department at Salford university myself... But if those resonances, and the associated, cyclic, plate deformation, were to impact on the loudspeakers performance then it would show up in deviations of the drivers transfer function and in the harmonic distortion.

They could have just done linearity testing at high power levels into resistive loads for swept frequencies. Both for linear and non-linear distortion.

I would be very surprised if it showed anything out of the ordinary. I mean sure it'll show up the parasitics of the device, if the equipment is sensitive enough and they fall within its bandwidth, but all the effects are almost certainly going to fall below the threshold of audibility.

As to their claimed blind test? I'll take that with a grain of salt.

Hell I could probably test this myself but I'd expect my amplifiers linearity to limit things before the cap does. And if that's the case then it's surely not going to be audible.

I don't mind being proven wrong but that white paper does nothing to change my mind as it's marketing produced by the company that wishes to sell their expensive capacitors. I don't doubt their findings of issues that capacitors can exhibit, what I doubt is their claim of its audibility. (Just how exactly was the test controlled etc?).

It's like some capacitor manufacturer trying to promote their super low ESR caps as something important for loudspeakers. Where in reality the ESR of any decent film cap is going to be low enough for correct crossover operation. I mean I've seen electrolytic ESR being a problem but that's when the wrong capacitor has been used, or a part has been defective.

[Scareurpasenger]

I am not familiar with bypass capacitors and from reading it sounds almost as controversial as speaker wires. I don't think this crossover has one. It is the Bagby crossover for the rs180mtm. It seemed like the most simple approach for the drivers compared to the others. If there were compromises in the design to keep parts list minimal, I am unaware.

[Bill Schneider]

Judging from the date of the crossover plans, be aware that the contemporary RS28A may be different than the one used in the design. There was a change in Dayton RS28A tweeters around 2017. They are different enough that Jeff used a Morel tweeter as a replacement in the Continuum II because the new RS28 was not a drop-in replacement.

You can read about it here... https://meniscusaudio.com/product/continuum-ii-loudspeaker-kit

The crossover shown above may require a little tweaking.

[Scareurpasenger]

Thanks for keeping a lookout for the newbie! I actually have the rs28as-4 tweeters which should be pre 2017. I will take some measurements to see how they fair and mockup everything as much as I can in software to see if I am missing something. Not to mention the learning opportunity.

[Bill Schneider]

That's super! You've got some great tweeters to work with.

[Scottg]

I am not familiar with bypass capacitors and from reading it sounds almost as controversial as speaker wires. I don't think this crossover has one.

OK, it's a 3rd order high-pass (electrical).

Bypass cap's are just parallel connected small value cap's to your higher value cap(s). Most of the time it's for an increase in perceived clarity (ex. Vishay). Sometimes you'll get some added spaciousness with better cap's like the Miflex copper-foil.

For the 10 uf I'd probably do an Obligatto Gold plus the Miflex as bypass. The 50 uF with just the Carli 20 uf and 2x 15 uf + another Miflex bypass (not the Vishay).

https://www.partsconnexion.com/OBLIG-74471.html

If I wanted to decrease the cost some, I'd swap the Obligatto for the Clarity Cap CSA:

https://www.madisoundspeakerstore.com/claritycap-csa-capacitor-250vdc/claritycap-10-mfd-csa-copperconnect-poly-cap-250v/

[5th element]

Except I've never noticed a lack of spaciousness without the bypass cap. What exactly is it it's supposed to do? From a technical point of view this is.

[Scottg]

Increased "sound-stage" (usually depth more than width).

It's probably an effect of mechanical resonance (..not its self-resonance where resistance is nominal). How that effects the sound, don't know. I think Clarity once spent some money researching this (..but you know: self-serving "quest" :cough: :marketing: :P ).

It's one of those things *you think is BS until you hear a difference. ops:

*or I did anyway.

Where I started "hearing" cap's subjective qualities wasn't with speakers, but rather SET's with low part's count particularly with speakers that were fullrange or "active". (..moving into minimalist additions to full-range drivers from there started me down this "slippery slope" with respect to loudspeakers.)

[bvbellomo]

I've been using Dayton Audio Polypropylene Capacitors for prototyping. At least as far as capacitance, they aren't far off spec, are cheap, and ship relatively quickly. Am I better off paying for something better or some of the other recommendations on this thread? Especially with a sealed design, it is nice knowing I can keep my prototype and make changes only infrequently.

And once I have a prototype I like, how do I upgrade? I have 40uF's in my woofer, 5uFs in my tweeter network, something similar to a Zobel to damp the tweeter near its FS (forgot what the correct name for this is) etc.

I can divide them into 3 tiers:
1) caps directly in the path of the tweeter
2) caps directly in the path of my mid
3) caps that 'cross' either as part of a higher order across a lower level driver, Zobels or similar.

Is it worth mixing 3 different price points of caps into a design?

I know this is subjective, and in a perfect world, I'd spend weeks listening to every line of every brand, or every combination. But I am not immortal, nor do I have millions of dollars for crossover parts.

[Scareurpasenger]

Well, I decided to give some CDE type 950 5% tolerance capacitors a shot. At 50uf, the price seemed a bit high for my budget to go with some Clarity CSA capacitors.

[bvbellomo]

I reread Jon's post and am confused what he meant by tolerance. "10% or 15% tolerance is not advised or recommended." after "you'll usually find when you QA parts incoming is that the tolerance spread of the capacitors is pretty narrow. But what that means is that most of the caps are right near the bottom of the capacitance spec- that is, XX.X uF, - the tolerance value. So it if it is a 60uF rated cap, and the tolerance is 10%, they generally come in very close to 54-55uF. It's just economics and specmanship, and the reality of what is possible with precision manufacturing."

If I can count on a cap labeled 60uF arriving between 54uF and 55uF, I don't see any point spending more money to buy a cap labeled 55uF if the labeling is the only thing different.

Aren't multimeter (or other ways of measuring) reliable? For protyping, I'd actually rather have inconsistent values. If caps are cheap but they only make a 50uF and 60uF, and I order 4 60uF and get a 52uF, a 54uF, a 55uf and a 58uF then I have a lot more precision tuning my design than trying a 50uF and swapping it for a 60uF and deciding which is better. When I upgrade, I may not get the same values - the nicer more expensive caps may offer a 52uF and a 58uF instead of the 50uF and 60uF I had to protype with.

[wolf_teeth]

I have used the JB caps original black and white models, and I didn't care for them. They are small form factor, so that could help in smaller designs. I still did not like them.
Later,
Wolf