Panelhead

I am far from an authority on horn termination. The tweeter on the LS ii looks worse the the mid. The mid changes to straight at motor board. The tweeter is flush mounted but has a gap all the way around. If the hole matched the K77D I would think it would be an improvement in function and cosmetically. But it sounds great regardless.

The pics above are as good or better than mine. I was confused by the cutout in the motor board and the size of the K77D. The K77D is really not terminated, there is a gap around the edge of the mouth. The K400 is rear mounted, the motor board is straight cut and a little rough in finish. Was told that the tweeter cut out is sized for the old style K77 with Z brackets. It also allows a little wiggle room due to the proximity of the Mid Horn and the top of the cabinet. One member mentioned fabricating an adapter flange to allow mounting the older style K77 horns in a La Scala ii. I think the project is in evaluation phase to judge potential demand. So far the market size is two adapters. I would also like to try the larger style horn and a B&C DE-10. But there is no way. The K77D is a tight fit. The termination of the mid horn mouth could be implemented better too. Continued flare and a machined surface. Both drivers play great by my ears. I overthink the details sometimes.

Claude, The best I can guesstimate the K55 diaphragm is 20 inches behind the K77 diaphragm. The vertical height difference is close to 4 1/2”. If my 10th grade geometry does not fail me, the top hat needs to be angled up at 77.3 degrees. This will time align them. Maybe sitting another driver on top of the top hat is a better option.

This has drifted a little from foil orientation in crossover capacitors discussion. The time alignment of the drivers is of interest. My previous speakers had slanted front plinth for time alignment. And first order crossovers. I will need to tilt the La Scala ii back to align the K55 and K77. I have seen where some have moved the tweeter and horn out of the cabinet and placed close to the mid compression driver. The K55 compression driver protrudes past the back panel on the LS ii. Aligning the woofer might be very difficult. The mid and tweeter would need to be behind the bass bin. That might be my solution. Remove the top hat and place behind the bass bin. Then tilt top hat to achieve alignment. This will require lengthening the cable from crossover to bass bin. So I am needing some speaker cables and something to balance the top hats on.

Which set of speakers has the Heresy squawker and tweeeter?

JSR, Good decision. The compliance of the should be close close even if one is a Pro version. Low compliance means lower output and lower efficiency.

They make very good equipment. I would invest 175.00 to find out. Very respected in the pro sound world.

I see a lot of talk on these ideas. But I am a man of action. These biwire Star Quad speaker cables are exactly 114.25” long. They do seem to sound better than two single runs of 16 ga. The initial transient on percussive attack is better defined. Whether half the resistance on the woofer cable, the Star Quad geometry, or being a multiple of 57.125” in length I cannot say. BTW, how is the speaker cabled measured? From tip to tip, binding post to binding post, or insulation to insulation? It is dark, sneaking over to Country Place Country Club to dive for golf balls in the water traps. Gators move slow when the water is this cold.

I will check my existing cables to make see if they are at least 114.25”. And make sure the new ones are close. I was planning on 120” but that was not a hard number. Perefect length was enough to make the span from amplifier to speakers. Being a EE I would assume that length in a copper cable is some percentage of the wavelength of a particular frequency. Since the relative velocity of the EMF wave is an approximation in copper cables a transmission line the significance of 57.125 inches long is tough to pin down. The most common number I see for copper cable is 0.7. Propagation coefficient. I suspect that is precision to one decimal point. If larger cables improves the system and having the speaker cables a multiple of 57.125 inches long is audible who knows what’s next?

I checked the other day and Mouser shows stock in the 5 ufd,1500 volt dc, Wima GTO. Most values were out of stock. Looked them up to learn something. Not much gleaned from the spec sheets.Good to see the inductance and phase plot here. Reading here I saw that most members who mention speaker wire used larger ga than I do. I think the 16 ga in the Canare 4S8 is fine. But slept on this. Rather than chop off a couple 10’ sections of 4S11 I will connect the 4S8 as a quad. And whack off a couple sections of 4S6 for the mid/tweeter. The latest Klipschorns and La Scala’s have Star Quad wiring. It has better noise rejection than twisted pair construction. The Quad connected 4S6 is 17 ga. I like smaller ga wire. I fact just thinking about it makes me feel better. HAVE Inc has great prices on these. I think you have to order a 100’ of the 4S6. I purchased a 100’ to internally rewire my La Scala ii and Heresy iii. But once I saw how the wire attached to the crossover board in the LS ii backed off. I assumed posts or connectors. Not hardwired to the circuit board.

I did read the spec sheet on the GTO cap. The use is as a damper on the gate of IGBT or other switchgear devises. Suspect it is lossy, this is how the snubbing or dampening characteristic is achieved. I am not adding to the crossovers in my LS ii. The film caps used by Klipsch are large. The caps are used to limit the bandwidth applied to each driver. This is a filter and not a power supply. Those GTO caps if ultra low impedance could be great in a power supply. But a wound cap that physically large should have high inductance. That is where stacked film caps shine. I am going to try one of the many ideas you have shared with us. Not ordering an GTOcaps from Mouser, heading to Golf Galaxy forisolations devices, ordering a load of M22759/11 from eBay. But am headed to the attic to gather some Canare 4S11 cable. Currently have the LS ii bi-wired with Canare 4S8 quad cable. Used as two pair, not as quad. This is 4x 16 ga. About 10’. The 4S11 cable is 4x14 ga wire. Will Open My Ears to see is going from 16 ga to 14 ga wires makes a change. The factory wiring used by Klipsch inside looks to be about 12 ga. Clear PVC insulated stranded wire. I normally prefer smaller ga wiring. Less is More. But honestly have not compared in a long time. I am going to make a bi-wire set out of 4S6 too. This is 4x20 ga. My math tells me this will work fine also. The speakers are high pass limited at 60 Hz. The efficiency is 105 dB at 1 watt. So maybe 100 mW to handle the 95 dB peaks. With dielectric effects, some capacitance slewing, and other non linear effects maybe 50 mA current spikes. I think 20 ga wire at 10’ can do that without breaking a sweat. I will let my ears decide if there is a difference between 20, 16, and 14 ga speaker wire used with a Klipsch speaker. If the 14 ga is a clear winner the 4S11 can be connected like a Star Quad to yield 11 ga cable with intrinsic noise rejection for connecting to the 15 inch driver. The 4S8 connected in a quad configuration is equivalent to 13 ga for the crossover splitting the K-55 and K-77. I like having the bi-wire cable in a single sheath. But this is about sound quality.

Back when I was into tubes I purchased some NOS tubes from Dennis when he was off of I-30 in the old movie house. That had to be 25 years ago. Think they were glass bottle 6SJ7. Had a 300B amp, still do, that used 6SJ7 for the front end. The glass bottles were better than the metal ones I had. He had a LOT of vintage amps and speakers in his Chimera Labs store.

Jeff, You are definitely out there dancing on the edge. Reminds a little of Ric Schultz ideas for system synergy. Welcome, your system is out of the ordinary. I think you need about three different wattage soldering irons. Some of the connections indicate the components were not up to temp and could have cold solder joints. Try a 40 watt to achieve smooth flow. But this will smoke the small film caps. That why you need three, a 12, 25, and 40.

I always orient text with signal flow. Does not make it right or wrong. With film caps in a crossover it is either OCD or cosmetics.

I guess moving south means something different to all of us. I was in Vancouver around the Holidays. That was almost as far north as I have been. Moving south for me would be south of the Rio Grande. Then I would have to step over the wall to come back.

I saw mention that the new wire used is an Audioquest Star Quad. To use the quad feature the opposing wires are connected. So it is doubled. This is designed to reduce the pickup of electromagnetic fields by the wire. The gauge should be no more overkill than the 12 ga or so wire used in my La Scala II. I think 20 ga would work fine.

A quality power is more important than quantity power. Ten watts is plenty. More is fine.

Way different tonal balance than a Lowther. I really like my Hiii. My pair surprised me with how good they sounded. Expected less.

Dave, My thought was a base that extended front and back of the vertical. For application like my LSii the middriver sticks out the back of the top hat. The driver would need to be very close to the rear for true alignment. The drivers are fairly light, a six inch base may work if it is 2 inches behind and four inches in front. Maybe not.

As I get older the looks of the speakers gets to be more important. If adding the 1/4” plywood is not a project you are willing to tackle, those braces should be easy and effective. Then veneer the outside. Add trim and the speakers will be very presentable. I prefer the looks of the one piece to the current design. When I had a pair of B&W 801 S2 in walnut sitting in exactly the same spot as the La Scala’s my wife commented repeatedly how ugly the 801 were. The top and mid/tweeter were black. Her only comment on seeing the La Scala was how much were these? I told her expensive, which she sets at around 500.00. The 70th Anniversary models shipping may have been close. At least to my wife the La Scala’s are not ugly. She may think she can flip them over on the back and put dirty laundry in the them down the road. Dual purpose. The jacuzzi tub in our master bath was dual purposed when we moved in 17 years ago. Holds a lot of dirty clothes. I do not have a lot of say around the house. Even in my listening area upstairs. Ugly speakers would be gone. BTW, nice find. Hope they bring at lot of satisfaction and happy listening.

The high pass filter could be a “trap”. The capacitor and choke resonate and dump energy between them. The “quality” of the components plays a role here. ALK, Deano, BEC, and others are more qualified to offer suggestions. I usually damp capacitors electrically. But in this case a swamping resistor across the final choke might be the most effective. Something like a 2 - 3K thick film, non-inductive in parallel with choke would identify if this is the issue. For the output coupling cap, a 0.536 ohm resistor in series with 0.1 ufd cap would be a start as a damper in parallel with the stock large value film cap. If I had a test rig I could check mine to see if they show the same peaks. I need an analyzer. It would be easy to drop back panel and jumper in components to see if damping the choke, caps, or both effect the amplitudes and width of the anomalies. BTW, I do not hear any misbehavior in my LS ii either.

Looks like you have sold your original LS ii. Guess that eliminates the small change in the crossover. My first thought is it is a resonance in the midrange horn. But that is also the second harmonic of the crossover point between the K-55 and K-77. High order crossovers can ring. If I understand the graphical display, there is a peak at 13.5 KHz. Which is the 3rd harmonic. That makes me think it is the high pass to the tweeter causing this.

Do both your LS ii has this Hi-Q resonance? The difference in the crossovers may address this? Shorting across that one resistor may be a “fix” for it.

I have seen comments that just adding veneer takes some ring out. I used to build horn cabinets a long time ago. Used to only use highly ply birch and in many places double thickness.Used a 3/4” roundover bit for front corners on router table and wrapped the fronts with veneer. Got good at right angle corners too. Looked professionally done sometimes. One trick I learned was to press an ear against a speaker panel at moderate playback level to hear how the cabinet was singing along. The output is way down and is offset by the difference in radiating area between the mouth of the horn and the cabinet. Sometimes the panels seemed full range. These were the cabinets I thought sounded the best. But using MDF the highs were attenuated. Try listening to your cabinets first. I still like option 2. But it is not my speakers.

I like option 2. Adding a 1/4” to the cabinet will stiffen a lot. Even the veneer helps. If it was not so heavy I would prefer one piece cabinet. My LS ii weigh 182 pounds. If one piece it would still weigh over 160 lbs. The AL-5 is 200 lbs, the top hat is now 1” wall MDF to match the bass bin. If you add a 1/4” all the way around it is almost the same wall thickness on the outside.