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If for no reason other than the fact that capacitors vary in their electrical properties from capacitor to capacitor, eh?
I've changed them and heard a difference.
Me, too.
However I do not know if this was due to closer tolerances, capacitor type, etc. They were the same values however and were not old.
The list of available answers is flawed. The correct answer is, "Yes, but only if the current capacitors are defective or not appropriate for the task."
Here's my submission for a more relevant poll:
"Who do you think is more qualified to choose which capacitors are used in a crossover - a professional loudspeaker designer, or an audiophile with no training in electronics?"
--Ethan
It depends on whether the judgment is being made while looking at a circuit diagram or while listening.
I trust the hard cold truth - and repeatability - of test gear over the frailty of human hearing every time. But you knew I'd say that.
--Ethan
ARGH!
A third variable: test gear!
That's what the scientist tells Kolchak right before the vampire kills him.
Measure any good symphonies lately?
Right on Elk. I think the string
http://forum.stereophile.com/forum/showf...e=0&fpart=1
more than provides enough PHDs, manufacturers such ARC, CJ, McIntosh, Atmasphere, and others, and all the engineers they employ, to pretty much dispell the myth that all capacitors sound the same.
The fact is that no capacitor is perfect.
I know you're kidding, but I see this totally BS argument often from believers. Obviously the "quality" of music cannot be measured, and nobody's opinion of a piece of music is better than anyone else's. Yes, I'll give more credence to the opinion of an accomplished musician versus Joe Blow on the street. But even then it all comes down to personal taste, and nobody's taste is wrong.
Versus the science of audio that is provable, repeatable, and - most important in this context - measurable. Suggesting that since music composition cannot be measured then neither can audio fidelity is disingenuous. The goal of audio gear is to pass electrical (and acoustical) signals with as little change as possible. This is easy to understand, especially compared to trying to understand some of the really out-there modern music I sometimes hear.
Okay, rant mode off.
--Ethan
Ah, I thought about something along those lines but mine would have been color coded like, "should you replace the blue OEM crossover capacitors with a color of your liking?" Or something like that.
Here's my submission for a more relevant poll:
"Who do you think is more qualified to choose which capacitors are used in a crossover - a professional loudspeaker designer designing to a price point, or an audiophile with no training but good learning skills in electronics?"
I do agree about price point, but a designer's credo should be like a doctor's - first do no harm. Further, in a loudspeaker crossover what costs the most is the inductor. And those vary more and harm the sound much more than capacitors. I think Pete mentioned that earlier in one of these "capacitor" threads.
--Ethan
Ethan (and others),
To what extent do a capacitor's manufacturing tolerances influence the sound? That is, leaving aside what the caps are made of - how precise need they be?
Could the better sound I heard when replacing the caps be due to the caps simply being "better" in that they met specs more closely?
It should indeed! And if that were how things worked in the real world of dollars and cents design, there would be no iron core inductors employed in any high quality loudspeaker. That's not the case if real life.
Let's take a look at the retail cost of two inductors, one an iron core, 18AWG, 10mH device and the other a higher quality Jantzen air core, 15AWG, 10mH device.
http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=266-580
http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=255-448&DID=7
Looking at the bulk pricing difference between $12 and $47 it's easy to see how a designer would begin to cut cost.
If you wanted the highest performance, lowest distortion component (considering only saturation onset), you would choose the higher priced, higher performance unit and significantly raise your cost per unit of manufacture. This difference in superior performance that will be appreciated by how many of your prospective buyers could easily place a particular speaker system well out of its target price range against it's otherwise lower performing competition.
You'll have to explain how inductors do much more harm than caps in a loudspeaker crossover, Ethan. I can only assume you primarily refer to the distortion product due the overly prevalent use of less expensive iron core inductors. That problem is one of choice, if the designer assumes his clientelle will drive the speakers hard, the designer will probably have to deal with saturation of the pole piece. If the designer assumes the speakers will not be driven hard or the system efficiency is very high, he/she will not concern themself with the problems most inductors create in terms of saturation distortion.
Otherwise, I would venture a guess that most voltage source type amplifiers will have a somewhat less difficult task facing them when driving a highly inductive load than a highly capacitive load. The voice coil of any dynamic driver is, after all, an inductor in itself. On the other hand, consider the problems an amplifier must face when driving the highly capacitive load of an electrostatic type loudspeaker.
A capacitor in line causes problems no matter the level only increasing with higher levels of current and lower frequencies. So a capacitor's effects are more constant where an inductor's effects can often times be considered a problem only under certain types of customer usage.
Jan is not allowed to shop at Parts Express. I think he is a closet Parts Express customer, he went there, got some stuff, and won't admit I was right, about wires, and lotsa other stuff......Jan buys from Parts Express, nah nah nah, I bet he added some speaker drivers onto his mid range, he added a woofer, tweeter, a crossover, and exclaimed, DUP is Right, I didn't know they had cymbals in this recording, my kid range didn't make a sound at that freq.
What you hear is what you hear and thus your second question is actually your answer. IMO you probably have a trained ear. I have a friend that can hear a pin drop in a room but he is tone deaf when it comes to music and knows even less about stereo equipment so to ask him if he hears a difference would be pointless. I would suspect that the designer of a crossover network would need to find a happy median to satisfy the average listener across the board of music preferences. Take my old SP2500s. Not only are the caps predetermined at the factory the designer went so far as to have a "Clear - Natural - Soft" selector switch for the tweeter system as well as the mid-range systems. I do hear a difference in that case. Which is better? Depends on the music, speaker placement, and so forth. I do use those switches BTW. But I see no need to mess with those old capacitors. I've seen no capacitors rated the same as these and I would probably burn out a newer replaced set even if they were "better". They wouldn't be for long.
Interesting. Do you know what is different about the circuit for each? Different value caps for example?
Burn out a new capacitor in a crossover? You must be thinking of bi-polar caps.
Unhappy Macnam! Unhappy Macnam! Systat, uptime, 9:01...
Nope. There are ratings on the caps. Nice try.
I'll look at them again tonight and post what is printed on them. Get a better image as well.
http://www.classicsansui.net/images/Literature/Speakers/SP2500%202.jpg
I think we may be on different pages. I have never seen a film cap burn out in a crossover. Yes, bipolars can go bad since they generally have a lower voltage rating which can be exceeded, and the general construction, materials, process used.
As far as special values, yes you may not be able to find exact values except from the manufacturer or combining caps together.
It depends on what the cap is used for. In a crossover you want the cap and inductor to be symmetrical, to avoid overlap or a hole around the crossover frequency. As the woofer falls off at the high end, the tweeter needs to take up the slack, and vice versa for going lower. So that affects frequency response.
If the left and right channels are not well matched the response will be different on each side, which can affect imaging.
Likewise in an EQ circuit, a mismatch between the left and right sides can pull the image to one side or another, depending on the frequency content of whatever is playing at the moment.
More likely any perceived improvement is due to expectation or comb filtering.
But you knew I'd say that!
--Ethan
No problem. These are bi-polar 35v rated capacitors. Links are to the full size images. Posted images are resized to fit the forum format. Depending on your browser setting you may need to mouse click on the image to get the full size. I have a set of 4 hooked to an HK 80w receiver/amplifier.
http://www.myculpeper.com/sp2500/sp2500a.jpg
http://www.myculpeper.com/sp2500/sp2500b.jpg
http://www.myculpeper.com/sp2500/sp2500c.jpg
http://www.myculpeper.com/sp2500/sp2500d.jpg
http://www.myculpeper.com/sp2500/sp2500e.jpg
Hi, I was wondering when you started this thread if you were referring to restoring some older equipment or just curious about changing them in general. How old are these speakers (I see 1970s there but just curious if you know the date of manufacture) and have the caps ever been changed?
Also, are those inductors laminated iron core or powdered ferrite, difficult to tell for sure from the pictures? Are they open core, that is just the E section?
I suggest that you hit any non-gas tight connections (solder is gas tight when done right) with DeOxit if you've not done it already.
Pete B.
They were manufactured sometime during 1974-1976. Caps have never been changed. Also, the screws to the board still have the factory seal unbroken. The following fact sheet describes E type ferrite core.
http://www.classicsansui.net/images/Literature/Speakers/SP2500%202.jpg
I've have never done anything to them. In fact, this is the second time I have ever took them out to look at them. The copper wiring looks the same as the day they were spooled on.
The only way I would consider doing anything to them is to get ones parted out and experiment with them instead. Other than that I see no reason to upgrade. They sound fine. The only complaint you may hear about these speakers is that the low is isn't low enough. Mainly because at the time only LPs and tapes were being utilized.
Regarding your first question here:
Electrolytic caps, which are pictured in your crossover, are rated by the Military for a 10 year shelf life. The specifications from the manufacturers are usually 2000 - 10000 hours at their rated temp and max voltage. This is usually an issue in switcher power supplies and applications such as automotive where the environment is harsh and hot. The chemicals in electrolytic caps dry out. The plates in an electrolytic require an oxide coating for the cap to operate properly, which is called forming the cap. Voltage on the cap keeps it formed, lack of voltage causes a very slow loss of the oxide layer. Electro's will slowly show a DC leakage current below rated voltage when they lose the oxide layer. Some brands are much better than others. I've seen some 30 year old electrolytic caps with high leakage, and 2 to 4 times their rated capacitance value. Others with 10 times their normal ESR, remember these are very old caps. I suggest changing electrolytic caps that are more than 10-15 years old in any vintage equipment. This is especially important in vintage speakers where it is difficult to get replacement drivers, since the leakage can damage the driver. So yes, it is important to replace old caps for these reasons.
Capacitor selection is complex NP electros are available in types for small signal (low current) and high current applications where the ESR is much lower. I've seen small signal NP electros with an ESR as high as 3 ohms but these are intended for low current applications.
Film caps such as polys and mylars for high current applications usually have much lower ESR than NP electros and this can alter the sound of a system if it is a critical location in the circuit. They do not rely on an oxide coating and tend to be stable with time. I have replaced NP electros with film type caps, when restoring vintage equipment, and added a small resistor to roughly match the ESR.
Pete B.
What would you do to these crossovers?
If you want as close as possible to stock I would replace the 2.2, 4.7, and 10 uF 35V caps with new high quality NP elecros but at 100V rating, just for a bit more margin on the voltage. I prefer Bennics as a good quality NP electrolytic, however my usual source, Madisound does not have those small values - you might call and ask for the smaller values:
http://www.madisound.com/catalog/index.php?cPath=404_5_304_6
You might find another vendor that has them. I'll take a look.
Note that Bennic makes cheaper higher DF versions and I would avoid those - I don't think that Madisound carries them.
If they were my speakers I'd replace them with low cost poly type caps with an added resistor in series. About .47 ohms should get you in the ballpark. Most NP electros for high current applications of this simple type usually have an ESR of .3 to 1 ohm.
The inductors and resistors look fine, you could check the resistors with an ohm meter and the switch contacts.
I assume that you're not keeping these as high value collector's items.
Pete B.
Thanks. That's a good start. No, I'm not keeping them as collector items. They are the only speakers on my system. I specifically sought these out for daily use. They compare favorably with Klipsch Heresy 2's at a fraction of the cost, naturally.
Look at the close up photo of the crossover's interior. Notice the "S", "N" and "C". Sound familair to "soft", "natural" and "clear"? The switches are wired to various taps off the inductors.
Love the "Squawkers" label.
Golly Gee, Jan - now that we have pictures I doubt any of the rest of us would have thought of this! Gosh you're clever!
Now, you funny too.
THIS will make it all better. What kind of oil is in these, maybe magic elixir type, oil of frog, GREEN OIL http://www.v-cap.com/oilcapacitors.html
"Truth" caps.....I'm sure they are very special...at +- 10% Yeah, real improvements!!!! http://www.modwright.com/modscaps/
75 cent caps, come on, pay $50 for them each, they will always sound better, paying more, these Madisound parts don't have a cool wood box or nutin'.
You know, it isn't easy finding reasonable axial NP capacitors to match those on the Sansui. Quit making fun of me Now, you funny too. Xicon is about all I can find through Mouser Electronics. These are the .50 caps. I can't find a reason for tearing up my crossovers for $1.50 in parts.
What?! You really needed a picture?
BTW, it just occurred to me that changing the original 35v caps with a 100v cap would be just as dangerous, if not more, than just leaving them alone. So, the only way I could consider changing them is (1) they don't cost $10 plus each and (2) they are rated at 35v. I dare anyone to find Bi-polar axial capacitors in 2.2, 4.7, and 10.0 uF and rated at 35v. Mini capacitors don't count.
Anyway, how can you check to see if there is any "leakage"?
No.
Sadly however you thought it necessary to explain the obvious - and to do so in a condescending fashion.
Well, excuuuuuuse me. You didn't seem to be figuring it out until now. You can see the "S", "N", "C" in the first photo posted before you asked the question and you can see the taps off the inductor. So let's not be giving ourself more credit than we deserve.
Man, all you people who say you know something but you sure don't tell anyone and I'm supposed to know what you say you know. Now that's condescending! Hey, Elk, your's stinks too. And it's getting pretty deep in here.
Now, if you want to cut the crap and start over like an adult ...
http://www.loudspeakersplus.com/html/eminence_xovers.html
The original caps are Rubycon CE series. Does it matter if any type of replacement is radial or axial leaders. Because Rubycon makes the ratings I'm looking except in Radial but I don't know if they are bipolar or not.
http://www.referenceaudiomods.com/Mercha...egory_Code=RUBY
Also look in www.newark.com And www.alliedelec.com Real supplier catalogs, no audio nonsense attached.
I looked at them more than once. Nothing that is a good match. I swear the only thing I can find that is a good match is the Rubycon radials. But I don't know if they are bipolar or not. If you can use radials instead of axial and NP then they will work. It won't be pretty but who cares. I still hadn't even done a basic test to the original Rubycons to see if they are leaking. I'm sort of doing this backwards as usual.
Or www.partsexpress.com or Digikey.com
Checked them too.
The lead outs determine how the cap will be mounted. If the radial leads won't easily accomodate your board that was designed for axial leads, then you shouldn't buy the cap with axial lead outs. Too much heat applied while soldering the wrong item onto your board in order to jerry rig a cap is likely to damage the cap and the board.
Why not go up in working voltage and look for something suitable? Going up is fine, going down is not.
Personally, I think you're stressing over something inconsequential. The caps in your speakers are old but apparently they are working. That should be the test of whether a cap needs to be replaced in a three decade old speaker of this general calibre. In all likelyhood you'd see it clearly if those caps were leaking. They've probably drifted from spec over the years but they probably started life with a fairly high tolerance from spec to begin with. I say play the speakers and enjoy what you have.
Thanks! I'm going to do the voltage drop test just for kicks though. It rained all last night. So, the shooting range is a mud field right now. I'm indoors today. Play some music.
We're just waiting for your next reply, probably something involving making fun of someone's name.
Jan, knock off the playground behavior, the name calling, the condescending dismissal of others and their ideas.
Have you not noticed that you are the only member that has fought with almost everyhone here and that the exchange typically ends with you hurling personal insults?
As you told Pete, this is the wrong place for you if you cannot handle those that disagree with you, or do not see the world as you do.
Perhaps if you sit on a piece of blue paper you will feel better. Don't forget to fold a corner.
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