geoff.

It looks like the red label says “ALK Engineering, Cornscala - Wall Universal”, and instead of massive coils for the inductors I see a steel core “bar” inductor just tucked under the K-55. Looks like the breadboard is MDF too (iykyk),lol! But THAT won’t affect the sound, here...

Fun score! K-33s come up often and pretty reasonable on the Bay. If you need two new woofers though I would suggest Kappa 15Cs, if they are in stock anywhere. They are not the bargain they once were, but they will “supercharge” the bass and play off nicely to the squawker. They are very similar in performance to the K-43 woofer that came in subsequent LSI iterations. Surprised yours didn’t have K-43s? Get them playing first and see where you want to go from there. As for finish, someone on here did theirs in piano black lacquer and it impressed the heck out of me. Above my paygrade but beautiful. Veneer would be sweet too. I have two pairs of LSI Splits that I have modded. One pair has A/4500 crossovers and DE-120 tweeters on SMAHL lenses, the other has homemade ALK Universal crossovers 6db down on the squawker. I think I prefer the A/4500 combo... With a few relatively inexpensive 2 and 6.8 uF capacitors and a switch of taps on the autoformer your AA crossover will shine.

That is an “economy” ALK CSW/Universal crossover, not an extreme slope. But that is not a bad thing, just cheaper. That is a whole lot of La Scala for a decent price, assuming the internals are stock and functional. You would have to spend a lot more to arrive at this experiment on your own time. As was mentioned, the accoutrements on top of the stock model would recoup a decent chunk of the outlay if you are not impressed, but you probably will be. If La Scalas are what you are after, these are pretty sweet foray.

@John kal, there are usually some pretty sweet audio deals to be had around Montreal and Quebec City. I have contemplated the same drive as you several times over the years. But just when I am about to commit to a day long journey something equal or better comes up in Sudbury, Ottawa, or Windsor and saves me a few hours. "There is no replacement for displacement." The biggest horns and the largest woofer(s) are where you will wind up. 300 watts will bring out the best of those KLF 20s in terms of bass. When I switched from a 150w/channel NAD C370 to a 300w/channel Emotiva XPA-2 the difference in the bass of my Chorus 2s was anything but subtle. As I said, that is a very fair price on those 20s, if everything else is good. You could probably sell them for at least that in a year if/when you find something bigger. Free rent, minus the gas...

Woofers love watts!

@Westcoastdrums, I resurrected an old PM, last time we spoke you were sharing a cache of Klipsch speakers from a closed cinema with the community for a song.

@John kal, those are nice speakers and a damn fair price with those “upgrades”, ESPECIALLY up here. That’s like a minimum $400 CDN upgrade after exchange, shipping and duty. About what you will spend on gas to see them, lol. But you may find them a little “bright”. Some serious solid state watts will excite the woofers to be sure. Where are you located and what speakers and amp are you using now?

I immediately noticed the the red and black, in and out leads to the autoformer. That just makes sense. Not choking the capacitors with tightened zip ties makes sense too.

“Cable lifters”

Question? What value cap would I shunt across the woofer If I wanted cross at 400hz using the 2.4mH inductor in series? And would I need to change the polarity of any drivers?

There is an ALK B crossover schematic floating around somewhere. I bet it would be worth a try in these.

Pictures man, for posterity. ...plus, I can’t be the only one curious as to their looks

@Tanner., where are you located? If you are up for a project, keep your eyes peeled for Klipsch Pro gear, something packing the K-48 woofers would not fail to please.

...you will never know until you try it for yourself, have fun! Besides, your room accounts for as much of what you hear as your speakers. And where you sit in relation to the room’s effect. But as mentioned, just don’t fry your amp.

...that is a project, not a “set of history” too many red flags on the deal, for me and I love red flags, painting them yellow, and then ignoring them

Well that’s a check mark in all the right boxes! Passive, so the bass comes on strong right out of the gate? You don’t need to goose it to get it thumping.

Very interesting! What’s in the sauce?

Wow, thanks Mike. I was not aware of the effect the tweeter filter has on the squawker as a voltage divider when it comes off of the same capacitor, until now.

Hello @Ap112233 and welcome to the forum. Was there a particular model you were looking at trying? The bass impact from your RF7s will be tough to match from most speakers with less than a 15” woofer. But once you hear the midrange (truth) from a Klipsch 3-way you may find it hard to live without. Ideally you would find a pair you are interested in and listen to them with familiar source material and let your own ears decide.

Should the last capacitor before the tweeter in a constant K crossover be changed to three times the value of the first? For instance, the AA crossover would have a 2uF capacitor and the second 2uF capacitor would be replaced with a 6uF (or better). I have seen several posts over the years, the oldest by ALK, stating it is prudent to do this but it doesn’t seem to be “driven home”. Is that because it is common knowledge to most? I am in the process of recapping/cloning some crossovers and this just ran through my head.

...just don't call me cracker, I prefer the term "Saltine-American"

@bribassguy, the A/4500 crosses from the woofer at 400(-ish) hz to the K-400/401 in a Klipschorn, La Scala, maybe a Belle. The mid driver in a Cornwall will be very unhappy about trying to cross that low instead of 600hz to the K-600/601. It has to do with the size of the horn. Larger horns can safely cross lower.

There are different schools of thought on the 68uF cap. I think you are leaning towards an electrolytic(100V), as was originally used. Some suggest a film and foil in that value as well. The ones I see are rated 250V or 400V. I always found it odd that the driver that gets the most power has the lowest rated capacitor. You could parallel two 33uF electrolytics for a higher rating too. Klipsch does that very thing in the Khorns and La Scala crossovers. Something I read recently on here suggested always using the same values (ie. 33 + 33) when paralleling capacitors though. That jibes with my OCD. Another post suggested reversing the orientation of one of the paralleled caps as well. Something to do with the construction of the capacitor. Don’t forget the 2 x 2uF caps for the tweeter circuit. And if you have not soldered much, even if you have, leave the leads as long as they come so you don’t “fry” the guts of the capacitors when you are soldering them. Heat is the number one killer of capacitors.

Where's the "holy f...!" emoji on this thing?