La Scala Mid - High Crossover Point?

[Robbie010]

I am just starting to dial in the DSP settings for my clone La Scala but when I read various threads online, I am seeing variations in the mid to high crossover point, some saying 4000Hz, some 4500Hz and some saying 6000Hz.

 

I appreciate that I can tweak this to my hearts content, as and when I am comfortable playing around and measuring but what is the accepted norm for this crossover point?

 

Thanks

[Islander]

The early models with AA crossovers crossed over to the tweeters at 6000 Hz, then there was a newer crossover (maybe after 1985?  total guess) that crossed at 4500 Hz.  I haven't heard of any 4000 Hz. crossovers.

 

Someone more knowledgeable will likely pop by in the morning.

[Chris A]

I found that 4.9 kHz works best when crossing my 1982 Belle, not because of its attached midrange and tweeter horn lengths and geometries, but rather where the natural unboosted crossover point actually occurred.  I found there is very little overlapping bandwidth between the K-55 driver and the K-77 tweeter.  It's the K-55 that runs out of steam above 4.9 kHz.  Below that frequency, the K-77 tweeter sounds increasingly harsh.  Above that frequency, you dramatically lose SPL from the K-55 driver--you've reached the end of its passband.

 

 

If you're using a different tweeter than the K-77 you might could cross a little lower, perhaps as low as 4 kHz but you need to check the horizontal and vertical coverage angles of the tweeter you're using at these lower frequencies to ensure that your tweeter/horn isn't losing pattern control in either the vertical or horizontal directions.  I'd also recommend listening to both the tweeter and midrange drivers when measuring their output (REW) during their separate upsweeps.

 

Chris

[Deang]

Big difference between what a tweeter can handle being run at 24dB/octave as opposed to 6dB/octave. The AK-4 has 12 elements in the tweeter leg, so 36dB/octave or more.

 

Older solder lugged K-55-V and K-55-M run strong out to 6kHz.   

[JohnA]

Klipsch officially stated and used 6k up until about 2002 and then switched to 4500 Hz with a highly sophisticated Type AK/AL-4.  Depending on the squawker driver, either one could be right.  All of my older Heritage speakers run the 2-piece, solder-lug K-55-V that readily reaches 6k.  Early K-55-Vs, Atlas PD5-VH and modern K-55-X (?) drivers don't go much above 4500 Hz, maybe 5k. 

 

I can't remember which squawker and tweeter you ended up with, so I'm not sure what to recommend.