Disconnected KLIPSCH Horns Effect 8 Ohm Load?

[3-way]

Would the La Scala or Klipschorn still be considered 8 Ohm if the Mid Horn and/or Tweeter were disconnected from the crossover?
Should the leads be removed from the crossover inputs, outputs or from the horn?
Would an in-line Buss type fuse at the + speaker input effect the Ohm Load?

 

[santa]

I think so
As I recall, the DC resistance of the woofer is around 4 ohms,but the acoustical loading of the enclosure brings AC impedance to a nominal 8 ohms
The fuse should not affect the load much if any at all
Use a meter and take an ohm reading on your fuse and you will read a very low reading confirming that

 

[twiiii]

By convention the impedance of a loudspeaker was considered to be the lowest point in the impedance curve just above the resonance impedance peak of the woofer. So a speaker could read 8 ons say at 50 hx and be sone thing else through the frequency spectrum. In the old days they use to pad the tweeters and miss down because the woofer was the least efficient driver so the impedance would be higher for the higher frequency drivers. Id the speaker was ported there would be two resonant frequencies on either side of the tuning frequency of the port much higher than the dip just above the higher peak in frequency. Klipsch horns because the drivers are all horn loaded only the midrange is padded down a few DB and the tweeter was operated without any padding. Only being protected by the crossover and why the crossover had to be redesigned many times as higher levels were being asked for in the late 60's and early 70's . When disco music came along with the predominance of synthesized musical instruments fur there strain were put on all Klipsch speakers using the little EV t-35 tweeter. Thats when Klipsch started making their own more capable tweeter. Tube amps always prefer to have a load so if you are going to remove the drivers, put a low pass filter in front od the amp to protect the amp. 600 or 800 HZ filter should be fine and not effect the sound of the woofer section of the speaker passive cross over. You can always remove the passive crossover and use an electronic crossover set at 400 HZ.

 

[RTally]

Speaker impedance is over the full frequency range of the speaker. As twilli notes, ratings are typically a nominal impedance. A conventional three-way speaker has each set of drivers separated from the other sets by the crossover network. Removing the full tweeter and crossover network will not affect the impedance of the speaker because the woofer and mids will present the same impedance to the amp while the missing tweeter and tweeter crossover portion will present as an open circuit, that is, infinite impedance. The same is true for the mids.

I do not have the schematic in front of me and I do not feel like looking it up. Generally, disconnecting just the driver from the crossover will either cause an increase in impedance for that frequency range (2nd order and up) or result in an infinite impedance (1st order network). So it would be fine to disconnect only the driver to remove it from the speaker, but at the risk of wasting power through the 2nd order and up network.

An in-line fuse will add a very small amount of resistance to the speaker. Generally, the resistance of a fuse is so small that it will not have any measurable effect on amp loading.