Alright - Who can fire up a list of parts for RSII xover?

[240sx4u]

I ordered parts today, I am going to keep the large can 1600uf and do a 16uf bypass on it.

Ill let you know how it goes this weekend.

Evan

 

[geoff727]

The reason I ask for help on this, is due to the following:

The spec sheet calls for a cap with a value of 1600uf. What technology (type of cap) would be best suited for replacing this? The diagram does not specify voltage either, so I would have to assume that the voltage ratings are not that important (since a crossover is passive anyway)?

Parts Express, to my knowledge, does not inventory a 1600uf capacitor.

Any help would be appreciated.

MaxSeven,
You can just completely remove those 1600uf caps. Take 'em out. Cap values that large only pass frequencies above something in the 30Hz range anyway, so they're just acting as a sub-sonic filter filter to protect your woofers from that slow wo-wo-wo-wo excursion that you get from warped LP's. They don't need to be in the signal path, and they just help to muddy the sound. Enjoy!

 

[Arkay]

MaxSeven,
You can just completely remove those 1600uf caps. Take 'em out. Cap values that large only pass frequencies above something in the 30Hz range anyway, so they're just acting as a sub-sonic filter filter to protect your woofers from that slow wo-wo-wo-wo excursion that you get from warped LP's. They don't need to be in the signal path, and they just help to muddy the sound. Enjoy!

What happens when you play a warped record and you lack that protection? Or is your assumption that you'll always have a subsonic filter switched on in your amplifier? I wouldn't want to take any real/serious risk of frying one of the woofers, as they are not all that easy (nor cheap) to find.

Also, just how much difference will taking them out of the circuit make? I never thought the RS II bass was particularly muddy (although often one doesn't notice such things until after "the veil is lifted").

Obviously, it is nice to tweak every ounce of sound quality out of a system that one can, but at what risk? Just trying to put this in perspective, so as to best decide what to do (since I have these speakers, with those original cans still in the x-over circuit).

 

[Bunny]

Why don't you try it? Just do the high frequenties (and the mid) Xover. Listen to the speaker and after a month or something remove (bypass) the big caps. Listen and decide what you like more

 

[240sx4u]

^ I am down with trying this ^

I am working on the speakers right now.

Evan

 

[240sx4u]

Dave's parts list missed the 600uf large can caps. This may not be a real issue at all. On the original schematic the 600uf isn't on there. I am going to run to madisound tomorrow to grab a few caps to replace them. May not be needed, but I have gone this far!

Thanks! - Evan

BTW, two of the 12uf caps are actually films from the factory.

 

[MaxSeven]

That's damn interesting about removing (bypassing) the 1600uf cap. I'll bridge it over and see what happens. Actually, I'll do it on one first, and compare.

 

[geoff727]

It's interesting that Infinity put those lagre value caps in there on some of these models. However, I don't think they were on all the models, at least that's what some of the schematics show. The RS6 and RS8 schematics on infinity-classics.de, for example, show only the series inductors. Of the speakers that I've taken apart, the Infinities are, so far, the only ones that have had this "feature". If someone has seen other companies do the same thing, hopefully they'll chime in.

My RS-IIIA's are next on my upgrade list, as soon as 2 other [exasperating] projects are completed (hopefully soon). They have 1200uf of capacitance in series with the woofer (that'll be removed) and a 40mH shunt inductor across the woofer (it'll go too). The smaller series inductor will, of course, stay. Interestingly, the RS-IIIA seems to have a slightly different crossover than the RS-IIIB, which is what is reflected on the schematic on infinity-classics.de.

I can't remember what value of capacitance the RS-II's have in series with the woofer (which can be taken out). But one thing I do remember is that the schematic fails to list the shunt capacitor across the woofer. I think this was mentioned several lines back as a 600uf cap. If you feel the need to replace that cap because of it's age, then some electrolytics paralled with about a 10% film bypass should get the job done well. Like 550uf of electro's with a 50uf film (a Solen or something) paralleled across the top.

Haven't had much time on the forum lately. Too many projects and too much work. Hopefully, when the RS-IIIA's are all fixed up in a few months, I'll have a little more time to spend here.

 

[240sx4u]

More updates to come, but so far there is dramatic improvement over my worn out raggety ass old crossovers. No more dropouts, and better sound.

Stay tuned, jumpering that 1600uf cap did wierd things to the impedance. Max, don't pull yours out yet. I need to recheck it tonight. I installed a switch so I could just jump it out when I wanted.

Evan

 

[240sx4u]

Well, removing the 1600uf caps definitely changes the sound. Beware, it seems to change the impedance too. I have to recheck them. Not sure which way I prefer, but it seems like having them engaged is my preference as of now.

Otherwise, things sound really good. I finished up the 2nd speaker tonight and now they sound the same! No more problems. They are a lot brighter now, but I actually believe in letting components settle in. I have to adjust as well, the tweets always sounded silky smooth but the output was pretty lean in my case.

I now have the mids cranked, and it sounds much better. Everything seems "right" with them now.

I would reccommend getting the appropriate caps to replace the 600uf cap as well, I did a small bypass capacitor to it and the 1600uf cap.

Your mileage may vary!

Evan

This was right as I was going to install one crossover, there was a wiring mistake I saw during assembly so I took it back out. Tight fit for sure!

 

[Bunny]

Nice job... mine was like that too but I re-arranged some parts so it looks cleaner and more clear. But that will do just fine too indeed ;D

 

[240sx4u]

It looks like a mess, but actually there is quite a bit of room to work around the components. Came out about as well as I could have expected.

What parts did you use when you did your crossover upgrade?

Evan

 

[geoff727]

Well, removing the 1600uf caps definitely changes the sound. Beware, it seems to change the impedance too.

Yes, it may change the impedance. Possibly from removing a rising ESR value of the original capacitors. What was your specific experience with the change in "sound"?

 

[240sx4u]

I would describe the sound as "different"

Still not totally sure what the big change was, I have to do more listening. I did prefer it with the cap in the circuit. Seemed more "right" to me. This was a brief test.

My DCR dropped like a stone though, if my measurements were correct. It dropped to 2 ohms roughly. Ill have to re-meter one after I get a chance.

Evan

 

[geoff727]

I'm looking forward to hearing your results. It's probably my fault, I should have said something about that. Removing those caps will remove the basic low-frequency capacitive reactance of the cap itself (which is not there in most speakers, anyway), plus any ESR that has built up over the years. With my system, I tend not to worry too much about low impedance considerations. But, others may be REALLY concerned about it, since a lot of Infinities dip down into the impedance depths anyway. The education continues........

 

[geoff727]

Evan,
By the way, have you considered replacing the old resistors in the midrange contour network with some good ones? The Mills are a good quality, inexpensive resistor (about $3.50 a piece).
I hope MaxSeven's project is going well, also.

 

[240sx4u]

I had not considered doing the resistors actually. Thats relatively cheap considering how much everything else costs! Maybe ill throw a few on my next mouser order or something.

Yes, the Impedance is a big deal. Many amps have died at the hands of RS2s. I can drive a 2 ohm load without too much trouble, but many can't.

Evan

 

[geoff727]

Yep, the resistors are pretty inexpensive comparitively speaking, it's true. I just finished up putting parts together for the RS-IIIA upgrade, and those Mundorf caps and Alpha-Core inductors ain't cheap! Sometimes I look at my checkbook and think, wait a minute, for all the money I keep spending on this stuff, why didn't I just look for a pair of used IRS Gamma's (or something like that) and just call it good long ago? I thought my hobby was supposed to be listening to music, not building all this stuff! By now I could be buildig finances up, instead of continuing to tear them down. Aye, aye, aye.