Advice B4 Crossover

Paul 4430 · 23rd January 2012, 04:34 PM

I have a pair of JBL 4430 monitors and have been trying to bi-amp them with a modest BBE crossover. Not happy with results. I have a Bel Canto Set 40 for the top. Any low end amp and crossover suggestions? FW B4?

Cal Weldon · 23rd January 2012, 04:50 PM

Hi Paul,
I moved this over the the loudspeaker section.

Cal Weldon · 25th January 2012, 09:23 PM

Just bumping this as I am interested in others' opinions as well. Which model XO do you have and what seems to be the problem(s)?

VaNarn · 25th January 2012, 11:58 PM

The JBl constant directivity requires equalisation to match the 93dB sensitivity of the 15" bass driver.This is all explained on the Lansing Heritage site.Basically the level of the horn is reduced by 15-16dB at 1kHz and an approximate 6dB per octave corrective slope applied above 3kHz.

AllenB · 26th January 2012, 09:59 AM

Yes, this isn't straightforward. It will be difficult to improve on. The crossover will need to match the drivers in power and directivity, as well as equalising the horn, plus any other 'issues' that might be present.

You might be able to use an active crossover to mimic the transfer function of the crossover, if you can measure that. Otherwise if you're unable to take and convert polar plots of the drivers I would think it best to stick with the stock crossovers, unless there is a proven alternative.

Michael Chua · 27th January 2012, 03:37 PM

Quote:

Originally Posted by Paul 4430

I have a pair of JBL 4430 monitors and have been trying to bi-amp them with a modest BBE crossover. Not happy with results. I have a Bel Canto Set 40 for the top. Any low end amp and crossover suggestions? FW B4?

I have a JBL2342/JBL2425 with an 8" Peerless.

I had high expectations but ....FAILED

Back to the drawing board

23rd January 2012, 04:34 PM	#1
Paul 4430 diyAudio Member Join Date: Jan 2012 Location: Minneapolis, MN	Advice B4 Crossover I have a pair of JBL 4430 monitors and have been trying to bi-amp them with a modest BBE crossover. Not happy with results. I have a Bel Canto Set 40 for the top. Any low end amp and crossover suggestions? FW B4?

23rd January 2012, 04:50 PM	#2
Cal Weldon Speakerholic diyAudio Moderator Join Date: Jan 2004 Location: British Columbia	Hi Paul, I moved this over the the loudspeaker section. __________________ Next stop: Margaritaville Some of Cal's stuff \| Cal Weldon Consulting

25th January 2012, 09:23 PM	#3
Cal Weldon Speakerholic diyAudio Moderator Join Date: Jan 2004 Location: British Columbia	Just bumping this as I am interested in others' opinions as well. Which model XO do you have and what seems to be the problem(s)? __________________ Next stop: Margaritaville Some of Cal's stuff \| Cal Weldon Consulting

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Pass Labs B4 crossover questions	nicksgem10s	Pass Labs	19	27th January 2012 10:44 PM
B4 and using different pair of monoblock	edwyun	Pass Labs	11	2nd April 2011 06:42 PM
Is B4 still on the horizon?	Michael Rothacher	Pass Labs	12	14th March 2011 11:46 PM
Any news on B4?	Chul	Pass Labs	5	9th December 2009 03:50 PM
anyone build this amp B4?	space2000	Solid State	1	17th May 2008 09:06 AM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

25th January 2012, 11:58 PM	#4
VaNarn diyAudio Member Join Date: Dec 2010 Location: Ivanhoe	The JBl constant directivity requires equalisation to match the 93dB sensitivity of the 15" bass driver.This is all explained on the Lansing Heritage site.Basically the level of the horn is reduced by 15-16dB at 1kHz and an approximate 6dB per octave corrective slope applied above 3kHz.

26th January 2012, 09:59 AM	#5
AllenB diyAudio Member Join Date: Oct 2008	Yes, this isn't straightforward. It will be difficult to improve on. The crossover will need to match the drivers in power and directivity, as well as equalising the horn, plus any other 'issues' that might be present. You might be able to use an active crossover to mimic the transfer function of the crossover, if you can measure that. Otherwise if you're unable to take and convert polar plots of the drivers I would think it best to stick with the stock crossovers, unless there is a proven alternative.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read