JohnA

100 to 200. Switching from a SS amp with a 40 damping factor to one with 200 was a noticeable change very nearly obvious to a disinterested female. 😁

You might/should have serial numbers for your Heresies stamped into the edge plies on the top rear edge. If your Heresies have front mounted horns, they are II, III, or IVs. We can id the difference by components.

You could do it, but dropping the xover point to 4500 Hz and keeping the 6k - 9k EQ on the K-77-? will be tough. At 105 to 106 dB, the K-77s are a little hot, too. I believe you would need to double the attenuation of the Type AAs 21 dB/Oct to protect the tweeter. The literature indicates the lower crossover point results in nearly equal horizontal dispersion between the squawker horn and the K-77 at that crossover point.

More like 21 dB/Oct because of the built in EQ.

If you will adjust your load impedance, you'll get more accurate results. Woofer - 6.3 - 6.5 Squawker - 12.5 at 400 Hz Tweeter - 8 ohms (7.2 DCR) Your model does show the EQ built into the tweeter filter.

Each speaker needs its own amp channel.

Look at Acurus, Parasound and Rotel integrated amps. Note that you rarely/really don't need more than 50 watts/channel.

The easiest way to improve/restore the sound of 30 y.o. LaScalas would be to replace the capacitors in the AL-3 crossover. The AL-3 is a good crossover, designed for the K-55-M squawker. Consider replacing the autoformer and any inductors it the cores or windings are loose. A Type AA crossover of any kind is not a happy match to a system with a K-55-M squawker because the -M has, on average, 1 to 1.5 dB greater output than the K-55-V depending on frequency (but also within the output tolerances of the -V driver). Al Klappenberger's Universal crossover is VERY good and can be adjusted to account for the -M's output. Though the sound was clean and clear, I found them to be too bright because they run the tweeter at 105 dB, and higher at some frequencies, while the woofer and squawker run at 104 dB. Al has addressed this, but that adds even more cost. Your room may vary. As to bass horn resonances, they are there, but are only audible at pretty high volume. If you find a pair that needs some professional cosmetic help, have them add braces from the sidewalls to the doghouse, otherwise, enjoy them and don't worry. I had mine finished before I got an amp if enough to hear the resonance. Now, they are too pretty to modify.

BC, How old are your Heresy IIIs?

I'm pretty much with the rest. The cost of the amp/preamp is set by your checkbook. Pick an amp setup that does what you want and sounds good. You want phono? Streaming built in? Plays digital music? FM? I'm powering my H IVs with a refurbished Technics SA-300 receiver (35 watts). It works great and sounds good if you don't clip it. I have a Yamaha CR-820 (55 watts) on the shelf waiting to be refreshed. (I detest black components.) I'd suggest you look in the 50 to 100 watt range, with an emphasis on quality, low noise, high-ish damping factor and a relatively large power supply (high 4 ohm ratings). That should net a good sounding set that will comfortably drive your Heresies.

Put them back together and enjoy them until you can order a new diaphragm. The wrinkles won't be good for frequency response, but probably not fatal, either.

!981 should mean they came with square-magnet K-77-Ms and solder-terminal K-55-Vs, making them the best sounding of the Heresy Is.

https://www.coolerguys.com/

LOL1 No, they were made the way they are.

there is no visual evidence those capacitors are "dried out". In fact, those likely have no fluids at all and cannot dry out. Your speakers may well sound better with new, good film and foil caps, but you won't know until you listen for a while. Heresies of that era should sound forward and crisp, even bright. If they do, you don't need new caps.

There are a few slightly better drivers (is that what you mean by CD? that normally means "Constant Directivity.) for the K-400. You can try John Allen's A-55G; it has demonstrated lower distortion. You probably want to change to a Type AA crossover, or modify your AK2, a little for it. Your K-55-M is 1 to 2 dB hotter, depending on frequency and driver tolerance. The K-55-M is a good driver, with few problems. A driver with a 2" throat is not a good match to a horn with a 0.7" inlet/throat, regardless of the adapter. The advantage of a 2" driver is lower distortion at a given dB, outside the likely design and construction precision improvements. Are you really playing your Klipschorns so loud you can hear squawker distortion? It is often described as "frying bacon".

You need to upgrade! To this: https://classicreceivers.com/marantz-4400

If you had a multimeter, I think you'd have used it already. Since you likely don't, disconnect the bad tweeter from the crossover. Use a 1.5 volt battery, hold one wire to the negative terminal and stroke the positive with the other wire. You will hear scratching if the tweeter is good. If you don't, the bad tweeter needs a new diaphragm. Replacing a diaphragm is a precise, but not difficult job. It you hear scratching, the problem is in the crossover and we will need more data to pinpoint the failure.

M7 is mahogany and I believe 7 means a dark shade. They should have been quite handsome when new.

Also, please post your approximate location. There maybe someone close by that could help.

Award for best joke of the day!!!!!

The back air chamber volume of a La Scala is small already. Reducing it would hurt bass output. Don't.

https://www.estatesales.net/GA/Smyrna/30080/3028725?utm_source=treasure_tracker&utm_medium=email&utm_campaign=found_treasure&utm_term=klipsch

I have an unproven theory that speakers used often don't need cap replacements as soon as speakers not used much, especially ones stored unused. If your K-horns sound polite and laid-back, perhaps distant, you probably need new capacitors. Your K-horns should sound big, bold, out in the room and lively. I had one H700 from the early 60s that needed new caps and one that didn't. If you have Type AK crossovers, change them to AK-3s. Shop ebay and our Garage Sale section. If you decide to replace the caps, replace them with the exact values your crossovers have and use very high quality film and foil caps. They will be expensive. To a point, your K-horns deserve them. Somewhere around $100 each, you begin to pay for prestige rather than sound. Avoid metalized film caps, they tend to have a subtle, hard edged sound.

All you need to do is match capacitance and make sure to voltage rating is 100V or greater. One hundred volts into 8 ohms is 1250 watts. Yes, most capacitors for sale are electrolytic, because they are cheap and and small. For an audio circuit they tend to (perhaps subtly) change the waveform passing through them more than other caps and that is undesirsable.