Hi
I bought some quite expensive Mirage speakers a while back and the center channel packed up on me. So, I broke it open and found the crossover, which must have cost all of 3 bucks to build, has at least one bad cap.
I was sorely disappointed by the cheapness of the construction, and I figured I could do a lot worse than at least replace the 20-cent caps with some polypropylene ones. But here is where my innocense comes in. Two caps are the kind where both wires come out the bottom. And these seem to be polarized coz they have an arrow down one side. I went looking for a decent one at Parts Express (it's 470uf 25 volts) but it seems the most expensive one of these I can find is a princely 35 cents. 470uf also seems to be comparatively big...I could find plenty of expensive poly caps, but they were like 2.2uf or .47uf. And they are not polarized (although you probably guessed that).
It seems there are two kinds of caps here that probably do different things, but isn't it a bit pointless to spend 5 bucks on one and a miserable 25 cents on another? You don't get much for 25 cents these days - presumably it's the same with capacitors.
I've ordered another crossover (at least they only overcharged me about 15 bucks over the cost of the components; I was expecting at least 50, because these people seem to think we are all grateful we don't have to go and spend 200 bucks on a whole new speaker, so getting fleeced somehow isn't as painful) so if I can improve this busted one dramatically for about 12 bucks, I might as well rip em all out. They are probably going to crap the bed soon anyway. Whaddya think guys?
Also, after spending decent coin on some 12-gauge speaker wire I was pretty pissed off to find that these quite expensive speakers had the usual two-cents-a-mile wiring inside em. I don't see much point in replacing caps if I leave the crappy wiring inside, but I think re-wiring em up with the same 12-gauge would be tough. Not impossible for the woofer, but because of how the tweeter is installed it would be impossible to do much of anything to rewire that. The stuff that made me happy doesn't come in less than 12 gauge, and while I can certainly find thicker wire than the junk that is in there now, thicker doesn't necessarily mean better. They put these ridiculously impressive looking binding posts on the outside, which is just silly when you see what they are wired up with on the inside.
Thanks a lot for your time
Phil
I bought some quite expensive Mirage speakers a while back and the center channel packed up on me. So, I broke it open and found the crossover, which must have cost all of 3 bucks to build, has at least one bad cap.
I was sorely disappointed by the cheapness of the construction, and I figured I could do a lot worse than at least replace the 20-cent caps with some polypropylene ones. But here is where my innocense comes in. Two caps are the kind where both wires come out the bottom. And these seem to be polarized coz they have an arrow down one side. I went looking for a decent one at Parts Express (it's 470uf 25 volts) but it seems the most expensive one of these I can find is a princely 35 cents. 470uf also seems to be comparatively big...I could find plenty of expensive poly caps, but they were like 2.2uf or .47uf. And they are not polarized (although you probably guessed that).
It seems there are two kinds of caps here that probably do different things, but isn't it a bit pointless to spend 5 bucks on one and a miserable 25 cents on another? You don't get much for 25 cents these days - presumably it's the same with capacitors.
I've ordered another crossover (at least they only overcharged me about 15 bucks over the cost of the components; I was expecting at least 50, because these people seem to think we are all grateful we don't have to go and spend 200 bucks on a whole new speaker, so getting fleeced somehow isn't as painful) so if I can improve this busted one dramatically for about 12 bucks, I might as well rip em all out. They are probably going to crap the bed soon anyway. Whaddya think guys?
Also, after spending decent coin on some 12-gauge speaker wire I was pretty pissed off to find that these quite expensive speakers had the usual two-cents-a-mile wiring inside em. I don't see much point in replacing caps if I leave the crappy wiring inside, but I think re-wiring em up with the same 12-gauge would be tough. Not impossible for the woofer, but because of how the tweeter is installed it would be impossible to do much of anything to rewire that. The stuff that made me happy doesn't come in less than 12 gauge, and while I can certainly find thicker wire than the junk that is in there now, thicker doesn't necessarily mean better. They put these ridiculously impressive looking binding posts on the outside, which is just silly when you see what they are wired up with on the inside.
Thanks a lot for your time
Phil
Hi
Well, as I said, because of the way these things are built there is no way I can do anything with the tweeters without completely dismantling everything.
But for the rest of it, anything heavier than 24 gauge would be an improvement over this rubbish. I can get 18 gauge "speaker wire" from anywhere for 5 bucks, but just because it's thicker doesn't necessarily mean it's better. For sure, it couldn't be any worse.
It just seems pointless, having invested in quality wire to get the signal to the terminals, to have it come to a screeching halt because Mirage decided to save a nickel on wire. It would have made more sense had they spent half as much on the impressive binding posts and spent in on decent wire instead. But I guess a lot of people see the lovely binding posts, while far fewer see what they are connected to inside.
Phil
Since the distance from the crossover to the drivers is so small, the wire hardly matters. I can't see needing more than 18 gauge for that short run. Bigger won't hurt.
As for caps, it's a bit odd to see polarized caps in a crossover, tho they can be connected head to tail to make a non-polarized. If you really want to replace them, try some Panasonic FM series caps. They are very good, and don't cost much.
EEU-FM1E471L Panasonic Electronic Components | P12389-ND | DigiKey
or the 35V version, if they will fit:
EEU-FM1V471 Panasonic Electronic Components | P12415-ND | DigiKey
As for caps, it's a bit odd to see polarized caps in a crossover, tho they can be connected head to tail to make a non-polarized. If you really want to replace them, try some Panasonic FM series caps. They are very good, and don't cost much.
EEU-FM1E471L Panasonic Electronic Components | P12389-ND | DigiKey
or the 35V version, if they will fit:
EEU-FM1V471 Panasonic Electronic Components | P12415-ND | DigiKey
This would be a good choice.
470uF 100V Radial Mini Electrolytic Capacitor 020-1324
Only Electrolytics are cheap enough at that high value.
Enough Poly for 470uF would cost a fortune. Also it would be physically very large. A digital camcorder can use a dozen or more. The camcorder would be the size of a microwave oven.
470uF 100V Radial Mini Electrolytic Capacitor 020-1324
Only Electrolytics are cheap enough at that high value.
Enough Poly for 470uF would cost a fortune. Also it would be physically very large. A digital camcorder can use a dozen or more. The camcorder would be the size of a microwave oven.
As for voltage rating the one I suggested was a 100volt.
For Pro with a 500watt to 1kwatt woofer I try to use a 400volt (Solen brand Poly). If I have to I will go with a 100volt Benic “Blue” if the capacitor value is above 40uF.
But we are dealing with an antique home audio woofer as the largest voltage draw.
I can’t recall the rating on the Time Window is, but I would bet it is between 30watts and 100watts so the 100volt capacitor is over kill.
OK, lots of stuff here.
I wish I could supply pics, but I have no means to do so. All I can tell you is that they came out of a Mirage Nano CC, but I was unable to find a picture of the crossovers on the web anywhere. All I know for sure is they are about as cheap as they possibly can be.
The ones you have suggested as replacements are interesting insofar as although they seem to have the right properties, they are all considerably larger than the Bennic type that I took out...the Parts Express offering is over 3cm tall, whereas I'm looking at the Bennic right now and I doubt it's 3/4 of an inch tall (I'm an old-fashioned Imperial guy and can't hold to these new-fangled measurements).
Too-Tall, thanks for the explanation re the Poly issue, but i have no idea what a Time Window is, and these are 80-watt HT speakers I'm describing, not 1000-watt pro drivers or antiques.
Pano, they were mounted back to back, so you were probably right about it making them non polarized, but then, why wouldn't they just use one non-polarized cap in the first place? Also, I did not note how they were inserted before I pulled em out, so I would not know how to put the new ones in to achieve the "non-polarizing" effect you described.
They are the first components on the board immediately after the input wire +side, if that helps any?
I wish I could supply pics, but I have no means to do so. All I can tell you is that they came out of a Mirage Nano CC, but I was unable to find a picture of the crossovers on the web anywhere. All I know for sure is they are about as cheap as they possibly can be.
The ones you have suggested as replacements are interesting insofar as although they seem to have the right properties, they are all considerably larger than the Bennic type that I took out...the Parts Express offering is over 3cm tall, whereas I'm looking at the Bennic right now and I doubt it's 3/4 of an inch tall (I'm an old-fashioned Imperial guy and can't hold to these new-fangled measurements).
Too-Tall, thanks for the explanation re the Poly issue, but i have no idea what a Time Window is, and these are 80-watt HT speakers I'm describing, not 1000-watt pro drivers or antiques.
Pano, they were mounted back to back, so you were probably right about it making them non polarized, but then, why wouldn't they just use one non-polarized cap in the first place? Also, I did not note how they were inserted before I pulled em out, so I would not know how to put the new ones in to achieve the "non-polarizing" effect you described.
They are the first components on the board immediately after the input wire +side, if that helps any?
OK if they were mounted back to back you can replace the two of them with a single 235uF (or closest value) non-polar electro.
You could consider paralleling a 15uF film cap with this 220uF non polar 220uF 100V Non-Polarized Capacitor 027-368.... I've never tried mixing non-polars with films, others may be able to opine wether it is a good idea or not
Tony.
You could consider paralleling a 15uF film cap with this 220uF non polar 220uF 100V Non-Polarized Capacitor 027-368.... I've never tried mixing non-polars with films, others may be able to opine wether it is a good idea or not
Tony.
Simple answer is space (and cost) do you know how big a 235uF poly cap is (assuming you can find that value)? film cap is basically any plastic film cap but when discussing crossovers it is generally accepted to mean a polypropylene cap
edit: 200uF is the largest poly cap partsexpress has, it's dimentions are 58 X 85mm you could also get a 33uF and parallel it to get pretty close to the 235uF... note that the two 470uF electros are probably around +- 20% tolerance!
Tony.
do you know how big a 235uF poly cap is (assuming you can find that value)? film cap is basically any plastic film cap but when discussing crossovers it is generally accepted to mean a polypropylene cap edit: 200uF is the largest poly cap partsexpress has, it's dimentions are 58 X 85mm you could also get a 33uF and parallel it to get pretty close to the 235uF... note that the two 470uF electros are probably around +- 20% tolerance!
Tony.
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My mistake!
That is a polarized part number I sent you.
Though you can make a non-polarized out of two polarized I just buy the Deep Blue Bennic that is already Non-Polarized.
Here is the correct parts numbers to make a 470uF Non-polarized 100volt
Parts Express
027-368
This is a 220uF 100Volt
027-370
This is a 250uF 100volt
Wire these in parallel and they will "add" to 470uF
About $6.18 for the pair.Note- In another post you wanted to know what "Film" meant in relation to capacitor.
Film types are "Mylar" and "Polypropylene" used for the construction.
snip-
For capacitor sizes they vary for several factors.
Foremost the type of construction material used.
Electrolytic, Mylar, Polypropylene
Next the thicker the material the more voltage it can take before it arcs through from one layer to the next.
So if we look at a 25volt and 50volt they are much smaller compared to a 100volt.
And finally the value of the part such as 20uF or 200uF
So you can have a 35uF poly 400volt that is huge and expensive and a Bennic Non-Polar electrolytic 200uF 50volt that is tiny in comparison and dirt cheap.
And then you have the “Audiophile” brands that will max out your credit card with only a few items.
IMO Solen 400Volt Polypropylene is a bargain considering price and ruggedness.
The Mylar caps cost close with a 250Volt capacity.
To find something with a big change in price you have to go down to the Bennic 100Volt.
Above the Solen 400volt capacitor the price jump is huge!
Your 470uF 100 volt Bennic is $6.18.
A Solen 100uF 400Volt Poly is over $30
OK, now I remember using Wintermute's idea of using the two caps from a project I did a long time ago building some 18dB crossovers with a friend. I would probably go with the Dayton polypropylene caps; I don't intend to get involved with boutique caps, as the speakers themselves probably aren't worth it.
Having ordered a new crossover I can fool around with this one and rebuild it for a few bucks and see how it sounds. The problem is, if I do improve it (and I suspect it will, quite dramatically) I am probably going to put myself on the hook for improving the other four. No wonder our wives (those of us who have one left; I have one, but I don't know where she is) just don't get it.
Phil
Having ordered a new crossover I can fool around with this one and rebuild it for a few bucks and see how it sounds. The problem is, if I do improve it (and I suspect it will, quite dramatically) I am probably going to put myself on the hook for improving the other four. No wonder our wives (those of us who have one left; I have one, but I don't know where she is) just don't get it.
Phil
At the moment I am liking the idea of paralleling a poly cap (I now recall doing that before in some crossovers a long time ago). Parts Express has a 15uF Dayton poly for 5 bucks.
BUT
Tony says use a single 220uF +15uF cap while Too-Tall has given me two electrolytics for a total value of 470uf
Problem is, I may have clouded the issue from the get-go because in my initial post I don't think I made it clear that I pulled TWO 470uF polarized caps. You may have figured it out when the discussion turned to how strange it was to have polarized caps in a crossover.
But either way, I am now confused about exactly what value I should get: Tony's 235 (which makes sense coz it's half of 470) or Too-Tall's two caps for a total of 470uF (which also makes sense to me). Only one can be right (I suppose).
Parts Express has a minimum order of 20 bucks. I don't think Digikey does, but I'm sure Digikey doesn't stock Dayton polys. Any ideas on what make I could get from Digikey that isn't "boutique" please?
As an aside, I found 25v = about 50 watts. No wonder they retired themselves.
Thanks
Phil
Yes my assumption is that the two 470uF caps were installed back to back, ie in series. Capacitors in series reduce in value. The same equation can be used as as for resistors in parallel.
So you get 1/470 + 1/470 and invert to get the answer 235uF. This is only valid if the two 470uF caps are indeed connected in series If there is anything else connected at the junction of the two caps then you won't be able to substitute in a single smaller cap.
Tony.
So you get 1/470 + 1/470 and invert to get the answer 235uF. This is only valid if the two 470uF caps are indeed connected in series
If there is anything else connected at the junction of the two caps then you won't be able to substitute in a single smaller cap. Tony.
It could be part of an LCR Notch filter as well. Or perhaps even part of an impedance compensation network, but I guess DC protection is a possibility... interestingly a textbook 8 ohms 1st order crossover at 85Hz calculates as 233uF so maybe it is a passive 1st order at around 80Hz.... Though why you would bother in a HT speaker which presumably will be used with a reciver that already filters below 80Hz I'm not sure.
But yes the actual crossover schematic would help
Tony.
But yes the actual crossover schematic would help
Tony.
Yes my assumption is that the two 470uF caps were installed back to back, ie in series. Capacitors in series reduce in value. The same equation can be used as as for resistors in parallel.
So you get 1/470 + 1/470 and invert to get the answer 235uF. This is only valid if the two 470uF caps are indeed connected in series
Tony.
and the two in series the voltage doubles and therefor can handle 50v. If you want to learn about capacitors you can download my free ebook:
All about capacitors, a free book download. - The Book Worm
Mac
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