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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => Installed Sound/Contracting FUD Forum Archive => Topic started by: Rain Jaudon on August 09, 2009, 11:06:35 PM

Title: JBL AC2215 horn swap - possible?
Post by: Rain Jaudon on August 09, 2009, 11:06:35 PM

Thought about this over the weekend and have not called my folks up at JBL.
Figured I'd ask here -

I have three JBL AC2215 cabinets.  100x100 horns in them right now.

I'd like to reduce this horn size to the 90x50 on two of them and the 60x40 on the third.  
Large undertaking?  Impossible request?
Easy to do since everyone has those horns laying around the shop collecting dust?

Thanks
Rain

Title: Re: JBL AC2215 horn swap - possible?
Post by: Tom Young on August 11, 2009, 06:30:36 AM

If JBL did their job well they designed the crossover, passive filters, a pad and (doubtful but possible) chose the drivers based on that specific horn.

Changing horns will have several unpredictable results: the HF's will be louder (as you increase the Q by going with a tighter pattern horn), the crossover will be changed as will the frequency and phase response.

If these were actively crossed over loudspeakers and you were reasonably adept with Smaart or other "complex" measurement, you could change HF horns and do the necessary compensation. But you would also need DSP or a bank of separate analog processors including crossover, parametric EQ and limiters. Plus a digital delay. The crossover would need to offer several types of filters and slopes to play around with and see how they effect the response, mostly around the crossover point.

Then there is the issue of how the different horns fit into the enclosure.

Not for the faint of heart