Infinity RSiiia crossover

michael1968

New Member
So I see there are quite a few different crossover designs and parts people use. Looking at my crossovers, they EXACTLY match the Infinity crossover schematic. So reading all of these posts about crossovers, can someone tell me which crossover design and parts work the best for these speakers? I could always just jump the gun and order the parts, but what is the best in the real world? I would like to get the bass going a little better on these. It seems my woofers were "lacking" some bass. I already ordered new surrounds for them.

Thank you for your help guys!!!
 
If you feel you have to recap, identify the electrolytics and just replace those. The other parts should be fine.
 
"Best in the real world" depends on your budget for new caps. I recapped my IIIa's for less than $200. Are the foams totally gone? You should check to see if the woofers are wired out of phase or not. If they are out of phase the speakers wont produce much bass at all.
 
Not sure why you phrased your question the way you did about the best "design"? Assuming all the cap are original, you should just go ahead and replace them because they have decayed out of spec.

Looking at the RS III-A spec I see only three inline capacitors, one for each driver, and one by-pass capacitor in the midrange wiring. Total of four capacitors per speaker. The capacitors below I have used and have been very happy with.

I would recommend you replace the 7uF tweeter capacitor and the 16.5uf midrange capacitor with Dayton Audio PMPC polypropylene capacitors easily found on the Parts Express web site. The 600mf NPE woofer cap you should replace with the less expensive NPE cap as well as the 5mf NPE by-pass cap.

http://www.parts-express.com/cat/capacitors/68

If you want to spend just a few more dollars I would highly recommend the Clarity ESA Caps for the Tweeter and the Midrange. They can be found at Madisound.

https://www.madisoundspeakerstore.com/claritycap-esa-capacitor-250vdc/

Remember that if you can't match a cap to the exact spec you can combine two caps in parallel for a combined number of what you need. Also remember that the original caps that Infinity used 20+ years ago likely had a tolerance of over 10% so as long as your replacement is within 5% of the spec value you should be fine.
 
The woofers were wired correctly. The surrounds are toast. Well, I see one schematic written by hand saying 1200mf cap for the woofers while the factory schematic says 600mf. I have a 50mh inductor while the hand writtem schematic says 40mh. There is also a 16mf cap running after the inductors on the woofer side. So a bit confused. I just ordered the new surrounds and the foam backing for the tweeter and mid. Just waiting for your guys input on these crossovers before ordering parts. I'll stick to the factory schematic and order the Clarity caps. Just got done sanding the cabinet, repairing the corners, and now time to stain the oak and paint the front and back. I haven't done anything like this in 17 years! Now that the ex wife is gone, I am finding my joys again.
 
Let me say this about the woofers; the surrounds were bad to where when I touched them, my fingers went through. For wiring, the two negatives are wired together with the bottom woofer positive wired to the negative binding and the top positive to the crossover.
 
just to clarify, the hand drawn schematics are the factory schematics. thats how infinity did them. they are generally trustworthy.

the computer-generated schematics with the NY address are HK's re-drawn versions of the schematics made after HK bought out infinity. these were done long after production of the speakers ceased, and are frequently wrong.








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photo

Here is a photo of my crossover. It follows the HK schematic perfectly. What I will do is totally make a new crossover to match the written cross over schematic. My woofers are also different from others I see. My woofers have dust caps on them. Yet the numbers on the back of the woofer match those of other RSiiia woofers. Do I have a bastardized set of RSiiia speakers????
 

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The guy I bought them from said he was Arnie Nudell's brother in law and that this was the second pair off the assembly line for the rsiiia speaker systems. I generally believe the older generation as they are my elders and most grew up with good morals. He spoke of Arnie and how his wife and brother in law(Arnie) never got along; how they wanted to kill each other. Maybe he was not telling the whole truth?
 
Thanks avguytx. I've been reading your thread! And that is what brought up my question on the crossovers.LOL. I just found out on a different thread that my woofers were hooked up incorrectly. So these woofers were out to be worked on, probably the surrounds. I am getting ready to buy the crossover parts(caps) according to what I have. I'll be using the good caps.
 
...
For wiring, the two negatives are wired together with the bottom woofer positive wired to the negative binding and the top positive to the crossover.
...

Wiring two negatives together (i.e. out of phase, i.e. opposite polarity) is incorrect, and will kill the bass. You need to connect one positive to one negative (i.e. in-phase, i.e. the same polarity) between the woofers. For pics, see here:
http://www.audiokarma.org/forums/showpost.php?p=8336803&postcount=60
 
Seppo- I just found this out reading someone else's thread about the RSiiia woofers. Also, MY rsiiia actually have the rsiiib crossovers, which I found on another thread also. So comparing the two crossover schematics, I would say the rsiiia schematics and components actually seem to be better than the b models, with the a models having the 1200mf caps for the woofers and not just the 600mf cap. Would you agree with this?
 
I was gonna say, from that pic you posted. Those are IIIB's. IIIa's have a panel on the back where the crossover is attacked. The panel can be unscrewed and pulled out. Are yours like that?
 
Nope. Mine were glued in. And it's just weird how it says rsiiia on the back, but clearly a rsiiib crossover. Do you consider the A crossover better than the B model? Has anyone did a comparison test? Last night I got the cabinet sanded, and the black front and back painted. I may be changing up the cabinet. Instead of staining the oak veneer, I may change the veneer to a birdseye maple veneer, or a burl walnut veneer. I came up with the idea after I fixed the corner pieces. I still may be able to pull it off if I use the 2 mil veneer.
 
Seppo- I just found this out reading someone else's thread about the RSiiia woofers. Also, MY rsiiia actually have the rsiiib crossovers, which I found on another thread also. So comparing the two crossover schematics, I would say the rsiiia schematics and components actually seem to be better than the b models, with the a models having the 1200mf caps for the woofers and not just the 600mf cap. Would you agree with this?

I have not had a chance to compare RS-IIIa to b. I remember someone saying earlier that they are practically the same.

One additional way to differentiate a from b is the text coloring in the mids and tweeters. a's have red/pink lettering, b's have blue lettering. Again, to my understanding the components are interchangeable for all practical purposes.
 
I think other than color of lettering on the EMIT's and mids, and the crossovers there is little difference in between the two. Also early IIIa's like mine have actual binding posts and not spring clips.
 
My iiia have blue lettering and the iiib crossover, yet iiia decal on the back. I am going to stick with this crossover and do a recap on them. I just ordered some birds eye Sapele veneer for the speakers. I get tired of looking at that 1980s oak.....
 
I will be very interested in seeing the outcome of yours being veneered! Looks like doing the fluted parts would be a pain.

If your "IIIa's" dont have the removable panel on the back. I am thinking they are IIIb's really.
 
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