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View Full Version : JBL PRO DIY center ch to match JBL 4343 or 4345



earspoiledbyjbl
05-06-2013, 02:40 PM
Hello all, here is my latest DIY. If any one would like the plans from the x-over to the box and speakers I'm here to help.588885888958890

hjames
05-06-2013, 05:18 PM
No offense meant, but if you are matching the 4343 & 4345 tonally, where is the Mid horn and slot tweeter?
The only way to really match the sound if you have 434x for mains is to match mids and highs in the center channel.

I use to run an LC2 center with my 4341 mains - and while it was nice - the tone wasn't consistent across the fronts.
After I sold them, I got matched Vandersteens on the front.
Now that I have truly matched fronts, I can hear what was lacking before.

But your center looks cool!


Hello all, here is my latest DIY. If any one would like the plans from the x-over to the box and speakers I'm here to help.
588885888958890

earspoiledbyjbl
05-06-2013, 06:04 PM
I understand where your coming from and here is the method of my design. My 4343 sit 14ft away from the main sitting spot and my center is 8ft so using the 2405 slot and 2420 horn was to hard on the ears. When I ran tests on my program and RTA using the 2405 and 2420 the dB was to much and I would have to put some fixed L-pads in the x-over to lower the dB being that close. As far as matching the sound both the new center and 4343 from 50Hz to 20kHz with no more then +-3dB change the sound waves were the same. The JBL mid and high I'm using has the same sound output as the 2420 and 2405 just not the same power handling. Thanks for the chat.

hjames
05-06-2013, 06:23 PM
I understand where you're coming from and here is the method of my design. My 4343 sits 14ft away from the main sitting spot and my center is 8ft, so using the 2405 slot and 2420 horn was to hard on the ears. When I ran tests on my program and RTA using the 2405 and 2420 the dB was too much, and I would have to put some fixed L-pads in the x-over to lower the dB being that close. As far as matching the sound, both the new center and 4343 from 50Hz to 20kHz with no more then +-3dB change the sound waves were the same. The JBL mid and high I'm using has the same sound output as the 2420 and 2405 just not the same power handling. Thanks for the chat.

Well, tonality is more than just matching the volume level, and yes,
you do have to pad the high and UHF driver down to match the level of the woofers -
that's what JBL did in the 3145 networks, but the bottom line is,
if you like the sound you've got, that's really all that matters!

Kudos on your DIY!

earspoiledbyjbl
05-22-2013, 12:15 AM
For the past two years I have been doing research and a lot of prototyping on the best all round center channel speaker for big format systems for home use (theater room), (man caves) etc. My main speakers are the JBL 4355, 4350, 4345, 4343 a set of 2245H in 6 cubic ft boxes tuned at 20Hz with a home designed paramatric bass EQ with a high Q @ 25Hz variable from -3dB to +6dB boost to get my 20Hz flat. I also have a set of 2235H in 5.5 cubic ft boxes also know as the JBL 380's. I have put together a range of JBL drivers to the test for center channel use here is what I did all were three way designs. First prototype for center channel was 2405H, 2425H, and two 2123H. Sec prototype was 2405H, 2420H, and two 2123H. The third prototype is 066, 2105H, and two 2123H. The box for the two 2123H woofers are hooked up in parallel and shares the same 3 cubic ft space and is tuned ported @ 38Hz the port is on the back of the box and gives a flat response down to 50Hz. The dividing network on all three was 800Hz @ 6oct slope and 7,5kHz @ 18oct slope the high and mid both have L-pads. All three designs were very great in performing and sounded amazing. The End conclusion I found was the 2405H, 2425H, and or 2420H was really harsh to the ears when watching a movie for two hours at a time in the main sitting spot for many of my Hi-Fi friends and myself. The center channel I kept is the JBL 066, 2105H and two 2123H. Everyone has their own views likes and dislikes this is the way I picked my way for the best all around center channel speaker setup. I hope who all read this find it interesting and with new ideas on going about their own Hi-Fi designs.

1audiohack
05-22-2013, 06:16 AM
Just curious, did I miss it? What horn was on the 2425?

Glad you got what you were after. :)

earspoiledbyjbl
05-23-2013, 04:31 PM
The horn I used is the back part of a 2344A mounted to the box and then used a 11 plate lens in front of it. The main angles were 30deg vertical and 90deg horizontal. If I was to use a 2425H for mid in a center channel that's the only one it would be its as close to a paper cone mid you can get with JBL pro stuff. The prototypes I used was just baffle fronts cause a closed box was not needed for the high end part of the project then when I found out what worked the best for my high end I built the box for the two 2123H.

gferrell
05-23-2013, 07:36 PM
Well, tonality is more than just matching the volume level, and yes,
you do have to pad the high and UHF driver down to match the level of the woofers -
that's what JBL did in the 3145 networks, but the bottom line is,
if you like the sound you've got, that's really all that matters!

Kudos on your DIY!

Heather, you always have a positive comment when it comes to this hobby! Thank you!

Mostlydiy
05-31-2013, 01:33 AM
My main speakers are the JBL 4355, 4350, 4345, 4343...

Do you live in a mansion? :)

Out of curiosity, which monitor do you prefer out of the ones you mension?

/Mostly

ivica
05-31-2013, 10:17 AM
For the past two years I have been doing research and a lot of prototyping on the best all round center channel speaker for big format systems for home use (theater room), (man caves) etc. My main speakers are the JBL 4355, 4350, 4345, 4343 a set of 2245H in 6 cubic ft boxes tuned at 20Hz with a home designed paramatric bass EQ with a high Q @ 25Hz variable from -3dB to +6dB boost to get my 20Hz flat. I also have a set of 2235H in 5.5 cubic ft boxes also know as the JBL 380's. I have put together a range of JBL drivers to the test for center channel use here is what I did all were three way designs. First prototype for center channel was 2405H, 2425H, and two 2123H. Sec prototype was 2405H, 2420H, and two 2123H. The third prototype is 066, 2105H, and two 2123H. The box for the two 2123H woofers are hooked up in parallel and shares the same 3 cubic ft space and is tuned ported @ 38Hz the port is on the back of the box and gives a flat response down to 50Hz. The dividing network on all three was 800Hz @ 6oct slope and 7,5kHz @ 18oct slope the high and mid both have L-pads. All three designs were very great in performing and sounded amazing. The End conclusion I found was the 2405H, 2425H, and or 2420H was really harsh to the ears when watching a movie for two hours at a time in the main sitting spot for many of my Hi-Fi friends and myself. The center channel I kept is the JBL 066, 2105H and two 2123H. Everyone has their own views likes and dislikes this is the way I picked my way for the best all around center channel speaker setup. I hope who all read this find it interesting and with new ideas on going about their own Hi-Fi designs.

Hi earspoiledbyjbl,

I only wonder why not use single mid-frequency (wide range) driver such as E110 (or E120) with 1~2 cft close box for the center speaker (with some amount of equalization in order to adjust levels and some frequency response peaks). I do not think that ultra wide frequency speaker ( 2420/25+2405...) would be a good solution for center channel speaker.

Regards
Ivica

Doctor_Electron
07-24-2013, 12:16 AM
Hello, I am curious... :blink: with that awesome system :D, what is the most impressive movie soundtrack you've experienced, and which also the most musical sounding? Is the average DVD movie's sound really up to the capabilities of (such as) your system?

These are for the "average Joe" unchartered territories, sonically. (IMHO).

rlsound
07-27-2013, 03:25 PM
Has anyone done a L-C-R setup with 3 4355? or 4350? Ultimately you need the same speaker across the front for the absolute match in tonality. Any harshness can be worked out with EQ.