upgrading speaker crossovers

I have a pair of PSB Stratus Gold'is and I am thinking of upgrading the crossovers, I am going to try this before I think about buying new speakers., which are in the area of $10000. The crossover in a speaker consists of 1-2.5mf 440vac film and 1- 6mf 440vac film by RC. then I have 4 100mf 100vac electrolytics. Why are the elecrolytics there, is this because of cost? I would much rather put in polys in their place, which will cost me $30.00 each. So my question is are the elecrolytics there because of cost issues if so can I change them to ploys?

My equipment consists of conrad johnson PV14l tubed preamp and a conrad johnson MF2500 amp. Both are right now at cj to be upgraded, the preamp is also getting teflon caps. I also have a pair of Mirage M1;s that I have upgraded with SI tweeters and Woofers. Must have gotten the last ones from them because now they will not even talk to you about the speaker when you call.

Anyway any advise on upgrading the crossovers would be greatly appreciated.

Replace those capacitors yesterday. Solen Metallized Polypropylene 100.UF 400VDC, 5% tolerance cost $38.81 per cap from Parts Express.
I would wait until your gear is back from CJ before deciding on which caps to use in the HF circuit. Solen would be fine for the LF and MP though.
Yeah, it's always a cost thing. The Solen caps will work better, Auricaps will work even better.....for more money. I've done surgery on about a dozen pairs of speakers, all with great improvement. I would also consider the internal wiring. It all goes in a positive direction. Use only silver solder. Good luck and enjoy.
The Mirage M1 bipolar was a special speaker, but the brand name is now part of the Klipsch mass-market stable and the M1 is a thing of the past.
Well I am going to upgrade my crossovers and remove all of the electrolytic and replace with poly's. I was looking at the Solens also, I can get the metallized polypropylene, 100 mfd 400 vac, for $30.00 each at Madisound speaker store. I will probably wait until I get my gear back from conrad johnson.

As for the M1's the company may be a thing of the past but the speakers still sound pretty nice.
Didn't mean to insult your M1s, Jchristilles. On the contrary. Discontinuing the M1 was a marketing decision, nothing more, and a sad one.

Looking forward to hearing how your crossover mod turns out, if you get a chance to post results.
No worries, but the Mirage name is not what it was, thats for sure.
When I rebuild the crossovers I will post it. It could be a few weeks or so, I want to make sure I do it right and replace all of the elecrolytic caps, total of 6 per board, plus the 2 film. Christmas is coming and the upgrades on my cj amp and preamp are my Christmas gifts, so money might be a little tight until after the holidays, not to mention the wifes gift.
If there is a discount to be had by ordering more, I would be willing to join you in purchasing the caps for my Golds. I assume they are the same as the Goldi as only the cabinets and port were changed.
The crossover parts may have been selected not just on cost but how they effect overall sound quality. Blindly upgrading crossover networks without understanding how they function or why certain parts where chosen,just with the thinking that if I replace with more costly parts performance will increase is very wrong thinking. But all who do always hear a improvement and that alone I would question. They also rarely if ever compare stock to modified so its just they I changed it it now sounds better to me. So upgrading crossover networks is mostly a waist of time and money unless you really understand how they function and why designer chose what they did.
I would assume that a designer chooses a certain value for a crossover component and then finds a part that matches that value. Each part has a tolerance. I assume the better parts have a closer tolerance and that the specified value is closer to the actual value than a cheaper part, on the average. Of course, tolerance means variance, so it is possible that the cheaper part could be closer in value to the design value than the more expensive part.

But then, I also assume that the more expensive part will provide a better sound experience, and here is where I think we go wrong. Why should it? What is it about an electrolitic cap that makes it sound a certain way? I dont know and maybe someone can explain that.
I was going to replace my capacitors with the same value just a different cap. There are electrolytics in there and I wanted to replace them with film caps. And if nothing else replace the 2 film caps, on the crossover with better quality same value.
Just got my conrad johnson gear back a few weeks ago. I had the mf2500 upgraded to the "A" version and the pv14l to the series 2 edition along with teflon cap upgrade. It is basically new equipment. I have just ordered Mundorf caps to replace the film caps on the Gold I crossovers and I am going to give that a shot first. After I will decide if I am going to replace the electrolytic caps. I was also thinking of replacing the tweeter but not sure yet.

If all goes right I might actually sell my mirage M1's that have upgraded SI dirvers in them from the tweeters to the woofers.
The 100mf caps and most likely a large inductor, are used to cross over the 10" woofer to the midrange driver.

Manufacturers are in business, first and foremost, to make money and that's why they use electrolytics. Specific values are chosen with the intention of blending each driver into the next one, while operating those drivers within their optimal frequency range. Aside from that, to many manufacturers, parts are parts.

Upgrading to better coils, resistors and caps should give you a more refined sound and probably eliminate some grain and glare.

If you're going to keep the PSB's I'd definitely think about replacing the tweeter. That's if you can find one with similar specs and it fits the existing cut-out. Sorry, but I hate metal dome tweeters. I've yet to hear one that didn't have a bit of sizzle and hardness on top.

Also, I'd stay away from tweeters with ferrofluid, which is what you have now. It's only purpose is to provide additional protection from idiots who do dumb things like clip their amp or short their speaker cables. Manufacturers hate warranty expenses and some go overboard to avoid it. There are resistors on the tweeters that provide all the protection you need. Unfortunately, they too reduce dynamics and often impose a fine layer of grain over the music.
I've not looked at the PSB Stratus Gold i's crossovers directly. I have looked at their design several years ago, seems I recall they were 4th order tweeter mid. The most dramatic change will be with any cap that is in the positive line in the tweeter or mid. Even though they are metalized polyprop, A polystyrene or Teflon in the tweeter/mid would make a larger difference than changing electrolytics out that are in compensation circuitry. It is not a bad move to replace the electrolytics, but depending on where they are, you might or might not notice much difference. Upgrading to better resistors is normally a good move also, but I have to disagree with changing inductor coils. Many coils have the resistance measured into the circuit and are part of the design. If you change a coil without properly compensating for the resistance, you could easily cause a more harm than good, many times alignment is thrown off and you get a smear in imaging and placement. This is all accurage information, I hope it helps, Tim
It makes an enormous difference. There is a very good range of Scottish speakers called Art. In their better ranges they offer each speaker in 3 grades of crossover, useing high grade capacitors and silver wire etc. You are quite literally, listening to a different speaker. The cost difference is enormous too. The Deco 10 goes from £10000 to £20000 with the upgrades. I queried the cost with a dealer, who said there is 40pounds weight of high grade silver alone in the crossovers.

Lou over at Daedalus Audio, is offering upgraded crossovers on his speakers. I have'nt compared them side to side, but those that have say there is a big difference. A word of warning, I dont think it is a matter of slinging any higher grade cap into the crossover. I am sure Lou spent months trying different capacitors by ear, before he made the change.
Why would it not be just a matter of slinging a higher grade cap into the crossover. if the values are the same, shouldnt they electrically do the same thing and then its just a matter of the better cap doing the same thing better?
Well a lot of good feedback. I ordered Mundorf Supreme caps to replace the two film caps on each crossover. Basically the same value but I am sure better quality. I am counting on smoother highs and a little more bloom in the midrange. These caps look like they are in line with the mids and tweets. I can now say that after upgrading my equipment I know what better quality caps can do. Trying to replace the tweeters could be a challenge because of the cut out, so I am hoping that the caps will do the job. They are in the mail so I expect to get them this week and do the change over this weekend. As for the electorlytics it does look like they are for the bass section, I can always pull one and check it out to see if the values are still correct and if not maybe get a better electrolytic to replace them, just thinking. And of course now I cannot use my turntable to listen as the needle in the cartidge is no longer there. Its a MC that came with it, Music Hall MMF 7. I am not sure if it is worth puting a new cartidge in it or getting a VPI Classic, which is more money, that I was not counting on spending after having my amp and preamp upgraded, but this is a different subject.
Why would it not be just a matter of slinging a higher grade cap into the crossover. if the values are the same, shouldnt they electrically do the same thing and then its just a matter of the better cap doing the same thing better?

you would think so and I'm sure any upgrade would have some benefit. Just reporting what Lou at Daedalus found in practice, that fine tuning brings added benefit. We all know there are real differences in the sinature of caps, regardless of quality.
I agree with Timlub when it comes to haphazardly replacing coils. On the other hand, I've had good experiences swapping out cheap 16AWG coils for 12AWG ones, particularly, the foil types.
Yesterday I replaced the 2 film caps on each crossover with the Mundorf Supremes. Did some listening and the speakers do sound better, the tweeters are not as brittle, the highs are still there but smoother sounding. I will need some time to burn in the new caps but I think this is what I am looking for, I will have to do more listening today. I just ordered my new turntable and will get it this week, can't wait until it gets here then I can try some vinyl.
For now I think that is all I am going to do the the crossovers, I want to let these new caps burn in, besides replacing those electrolytic's could prove to be a pain. Ever since I got my conrad johnson amp and preamp back from being upgraded the bass is great and they dig even lower, are more controlled and my soundstage is a little bigger, time will tell but it is as if I just purchased new equipment.
Jchristilles ,
Glad you got much improved results with upgraded Mundorf Supreme caps . What were the original caps that got replaced?
Did you not replace all caps ?
I am told by a technician at a speaker mfg company that one should have all caps on the X-over of the same type and from the same company and not to mix different varieties ( not even from same cap mag company ) , e.g. not to mix Mundorf Supreme with Mundorf Silve-Oil .
The supremes need a lot of time for break in... The first time they sound hard and poor detailed. They change completely after a long time burn in.
I asked directly by manifacture in cologne, they need about 200 hours, to sound right. You can shorten this time with excellent results using the astonishing isotek cd enhancer. It works incredible good.
Timlub is correct about inductors.
However, replacing an iron core with an aircore is not a bad idea, especially in the woofer end of the circuit.
At the same time, it is a Very good idea to match the DC resistance of new to old.
My inductor design for my Maggies is within 5% of 'stock' while going from 16ga to 14ga. This buys power handling, reduces any chance of saturation to near zero while not messing with driver balance or crossover frequency.

The advantage is that aircore doesn't saturate like an iron core does. This will be of most use to those who like it loud....no....louder.
The two film caps I replaced were small in size and said RC on them. There were only two films per crossover, the rest are electrolytic caps and to change them over to film would be a hastle since the electrolytics are Radials and the fims are axial, very tight. Still breaking in the new caps and now that I have my new turntable I am spinning vinyl again!

Still thinking if I should change the electrolytics or not.
Still thinking if I should change the electrolytics or not.
I would. Unless you have a very large value, not enough space, or are on a strict budget, they don't belong in speaker crossovers.
The electrolytics in question are 100mfd caps and are radial caps, the film caps are axial and are much bigger, so I dont know if I have the room to fit them. I can always take another look to see if it is possible to change them and if I can come up with a way to make them fit.
Many times iron core inductors are chosen for a reason. And the higher saturation of the iron core is factored into design. If one uses a aircore you reduce power handling and can raise SPL of woofer due to less insertion loss of the aircore which still has insertion loss just less of it.Another reason why just blindly parts swapping in networks can be a bad idea..
Jchristilles ! How's your Goldi now ? Better sounding ? I got a pair of Goldi too and would like to upgrade caps like you.
I think PsB is "audiophile speakers at affordable price" so i don't think Paul Barton would use exotic components . Business is business , rite ?
Ps : can i have the link to the store that you buy the M-cap pls , really cant find any caps with 6mfd and 2.5mfd . Thx
Is there someplace, maybe a psb forum, that discusses stratus gold upgrades ?

I have a pair too, would like to do an uprade. I really can't find a used speaker that can compete with it.