Kappa 7

[brunomarcs]

i won these for 200 on eBay pick up only. My son in law is in the army in Georgia and picked them up for me. Just got em today. The post is broken, how do I remove the crossover as there isn’t enough room to pull out? A little water damage on one but not bad. Refoamed with glue dripping out somewhat, grills and cabinets otherwise 9 out of 10 condition, one polydome is pushed in, I carefully hit it with my shop vac and pulled it out but it’s not perfect.

 

[Dan ʕ•ᴥ•ʔ]

You will probably have to remove the drivers...noting which lead goes where...in order to pull the crossover plate out. The post shouldn't be that difficult to replace.
You might ought to contact Infinity for an exact replacement.

 

[brunomarcs]

The cross over plate has a tight tight wire without any slack in it, I can reach in and feel it. Idk how they put it in. I can see the binding post is soldered. I’m wanting to get some good ones and replace all four. The polydome has a hole in it too, Does this have to be replaced or can we repair just the cover on it?

 

[brunomarcs]

It looks like the connectors are soldered on

 

[markuus3889]

I haven't been in mine in a while but the wire you're talking about is probably for the Midrange Polydome. It is a sealed internal enclosure with the wires coming into it and glued to prevent air movement.

Probably best to snip the wires with the soldered spade connectors at the connector wire interface and put new spade connectors on the wire. Then you can more safely out of cabinet remove the soldered on spade connectors.

The Polydome speakers, you should cut the wires a couple inches away from the poly dome and do not attempt to unsolder the wires attached to the Polydome. The small connection board on the Polydomes is easily damaged along with tinsel wires to the voice coil. The Polydomes are rebuildable by Millersound or sometime in the future a member here named Bobbyd38 will be reproducing the diaphragms for a drop in replacement.

I have never attempted to remove the Crossovers in my Kappa 7s so I'm not too sure what connections are there.

Good luck,

Mark K.

 

[brunomarcs]

To remove the crossover I feel as though I should cut all three sets of wires inside the cabinet? Is that how that’s done? The sets of wires are all bound in a ball of glue on the crossover board. Seen from woofer out of cabinet

 

[swechsler]

You really tempted fate by using a vacuum on the polydome, at this age they're incredibly fragile and can tear with the slightest provocation. They shouldn't need rebuilding unless they're torn.

There should be enough free wire between the crossover and the drivers that you can cut the wires close to the drivers (leave enough to strip them on both ends); you can then crimp or solder them back together. Make sure that they're all color coded differently; if not, then put some markers on them before cutting. With the polydome, don't try to remove the wire from the subenclosure, instead, cut the wire between the subenclosure and the crossover. Do NOT try to unsolder the spades from the drivers, you risk permanent damage to them that way.

 

[InAp]

Remove all the drivers , put a red mark on all the + and remove the xo

 

[brunomarcs]

If I’d would’ve known how rare and difficult it is to replace or find the polydome I never would’ve gotten anywhere near it with a vacuum, i held the vacuum about two inches away, moved closer and pulled it out, it has a small tear in it now, I believe the dome was damaged in transport as the grill is extremely close to it. I was able to turn the crossover and fit it in and out through the woofer hole. I’ll attempt to carefully unsolder these post as pictured. No need to cut wires as of yet. The damaged polydome is on the other speaker.

 

[swechsler]

I missed your second post about the polydome being torn. Chances are you're going to have to have it repaired; that's not the cover, the dome is what produces the sound. In fact, it would be much better to repair both so they sound the same. Repair involves replacement of either the dome or the entire diaphragm assembly (the latter is what Infinity originally intended, but parts are no longer available). There is currently a member here who is working on manufacturing replacements to manufacturer spec or better (use the search feature here to look for "polydome" in the title). Your alternative would be Millersound (find them with Google) who do a good job, but be warned that either method will cost as much as or more than what you spent on the speakers.

 

[brunomarcs]

Yep I’ve been reading up on these and I would do both domes at once. I understand it’s a bit of work but is it worth that much to replace the domes, seems high to me. I also see there isn’t a single replacement mid that anyone has used and been happy with. Why in this year and age no one has come up with an affordable solution? I went ahead and soldered the post on and a banana plug will stay in it, I tried to break it off with good force and it didn’t move. Will be auditioning them today. On the one with a spilled drink I’m gonna sand it smooth and am wanting to stain just the top, the rest of the carcasses are beautiful still, don’t know what color to use? You can see the outline of the poly on the grill, I’m thinking son in law or grandchild did that but I won’t say anything about it!

 

[swechsler]

The reason nobody has come up with an affordable solution is quite simply money. These drivers were custom made for Infinity; I'm sure there are legal issues involved with someone simply copying the design. There are already plenty of other dome midranges on the market, and a driver manufacturer is not simply going to design a replacement for a specific case (these drivers were only used in Infinity Kappa speakers) unless they know that there will be plenty of other buyers, since designing and tooling for a driver like this certainly isn't cheap. Currently the target market is extremely small, relatively speaking.

Now, as you've probably seen, Midwest Speaker Repair did get a Chinese company to build a cloth dome version, so we're getting close (although apparently sound-wise they're still not satisfactory, but it appears that the material that Infinity used is unique to these drivers (at least as far as speakers are concerned). Also, the cost of those replacements is pretty close to what Millersound charges for repair.

 

[brunomarcs]

Well I’m sold on Miller’s sound and am gonna send them both drivers as I found there site. I don’t like the reviews on the Chinese replacements Repairing this top is gonna be more involved that first thought.

 

[torfury]

Congratulations on the 7 Kappas. I am lucky to have a pair myself and love them. While I am fortunate that my polydomes and cabinets are all in great condition, other than warped speaker grills, I can comment on refinish. I also own a pair of RS-4a, which are nearly identical to the 7 Kappas. The top of one of them also had a spill that discolored and damaged the veneer. I used a palm sander with 120 grit paper to take down the finish and get it as flat as possible, and then finer grits until smooth as glass. (I don't know that I would concentrate so much on the slight warpage, although Infinity used great veneers) Then used Danish oil to bring back the beauty. Very simple process. I am sure any number of different refinish oils will work here, especially "restore-a-finish" that I have seen mentioned many times, but never used. Good luck with them as they are fantastic sounding speakers properly driven.

 

[brunomarcs]

Danish oil is all I need then? I won’t be able to get the top of the one flat as I held a straight edge on it and it is warped about 3/16” and I would sand through in to the particle board. So I can only sand a little of veneer, get it smooth and use the danish oil. The cabinets are built like a tank and very good quality.

 

[torfury]

Danish oil is all I need then? I won’t be able to get the top of the one flat as I held a straight edge on it and it is warped about 3/16” and I would sand through in to the particle board. So I can only sand a little of veneer, get it smooth and use the danish oil. The cabinets are built like a tank and very good quality.

Danish oil worked beautifully for me. I sanded very little to get rid of a very large and dark liquid stain. There is mild warpage, but it is not evident to the naked eye. The stain however is gone, and after several treatments with the oil, they look beautiful. It's worth a try, as your staining does not look to be as bad as mine was. I have also read that using a medium hot iron, with a towel between the stain and the iron could reduce, or even remove stains. I have not tried this on a speaker, but have on a dining room table for a water stain, and it worked well.

 

[brunomarcs]

I had a guy tell me to use mayonnaise can you believe that!

 

[torfury]

Wow! Mayonnaise?! That's one I have not heard of!

 

[brunomarcs]

The guy who said that has these same speakers and better ones too. He’s a carver guy and has done this since 78’. But I don’t have a stain I have a bowed spot so I’m a sand it. What about risers for these, any advice on that?

 

[torfury]

The guy who said that has these same speakers and better ones too. He’s a carver guy and has done this since 78’. But I don’t have a stain I have a bowed spot so I’m a sand it. What about risers for these, any advice on that?

I would have to say he knows his business then! As for the risers, I have none. The room I use mine in has oak hardwood floor, and I use a piece of that rubberized cabinet liner material under them. If you are a handy woodworker, I think I would be inclined to just make some. I guess I really don't have any specs though. I am not sure, but think the speakers simply sat on them. I could be wrong, but mine have no signs of ever having anything attached to the bottom. Then again, maybe they were and option. There are quite a few guys here that have 7 Kappas, so hopefully one will know the answer to this and post a reply.