@H.Huester , if you stay with the stock k-77s any variation of the “4500“ crossovers will likely result in fried tweeters
having said that, I have reached 100dB peaks at my listening position (less than 10 feet from speakers) with k-77-M tweeters using an A-4500 (I have six of them, I wasn’t worried)
the “4500“ variants are designed for aftermarket tweeters
I have built the ALK 4500 Universal, a polyester cap version of the Crites A/4500 (before Crites offered them) and most recently the 4500x (AA/4500 with extra goodies…)
the 4500 Universal did not impress me, at all, the polyester capped version of the A/4500 was an improvement TO ME over the stock crossovers any of my La Scalas came with, but the AA/4500 (4500x) is what sits in my La Scalas now, best imaging yet
once again, aftermarket tweeters are not optional
the ONLY crossover I found that made the stock k-77s remotely listenable TO ME was the standard ALK Universal, but that’s a lot of work to make something that was designed 60 years ago relevant
I have found the k-77-M to be harsh pushing anything close to 80dB, up to that point they are just “alive”, not sure if your Alnico k-77 tweeters would fare any better, but they are only rated 2W which is scary low power
are you able to follow a schematic and half handy with a soldering iron? You could relatively easily turn your A crossovers into AAs, or more down the road. Crites at one time sold a convertible A to AA board, you would only need two new components on each board and some fancy wiring
the AA crossover offers more protection for your tweeters as a result of the “slope” (third order) of the tweeter circuit compared to the A (first order), as Dean mentioned this also brings with it the benefit of better imaging
I have never heard an AA crossover with the squawkers (k-55-v) and tweeters (Alnico k-77) it was designed for, but I think it would be closer to an AA/4500 than most give it credit for. The K-55-V rolls off FAST at 4500 Hz and the Alnico K-77 does not have the energy below 4500 Hz the K-77-M has
if you do choose this path, or chose to stay with the A, my recommendation would be polyester caps all around to hear what Klipsch intended (transfer function) , …50 years ago
the analogy of changing a recipe before you’ve tasted it comes to mind, stick to the recipe and then change it after you’ve tasted it to suit YOUR tastes
but beware, lol
tastes change
