New Crossovers for 4343B

[Rolf]

Hi friends. Here are some pictures.

I can tell you that the installation, after several weeks of listening is a great improvement.

The direct cables from the amp to the woofer has resulted in a more accurate and more detailed sound. The new crossovers has resulted in a more "airy" and detailed sound. The only thing is that the 2405 has to be put on max position to keep up with the rest of the system.

Anyway, the improvement is at the total a +++ in sound. I will recommend all to change to CC crossovers.

Rolf

[hjames]

Weren't you running your system biamp before,
or is biamp new as well as the change to CC network?

[Rolf]

Weren't you running your system biamp before,
or is biamp new as well as the change to CC network?

Yes I biamp. The CC networks is for MF, HF and UHF drivers. The woofers are separate.

[hjames]

Yes I biamp. The CC networks is for MF, HF and UHF drivers. The woofers are separate.

Yes, so your woofers were directly tied to their amp before,
like most 434x biamp systems, correct?

the change is the new passive (for the other 3 drivers) is a CC network, yes?

[hjames]

Pretty much.

These bi-amp only networks we are building don't have the troublesome bi-amp switch in the path.

The 4343 network doesn't have any conjugates on the 2231 unlike alot of other JBL networks so the "bi-amp only" design only negates the bi-amp switch, a 5.4 mH inductor and a 72 uF capacitor. It's basically a charge-coupled 3140 network.



That's what we've been preaching. I know alot of guys think Greg is full of it with all his cool little tweaks but like he has said several times, they are optional. They don't have to be implemented by anyone. The continual assaults against his ideas serves no other purpose than to piss me the hell off.

Okay - based on what I read here I've been running the woofer directly off its own amp ever since I got my 4341s and had time to wire them that way. The Bass is crisp, firm and full and quite enjoyable. (Updating the networks will happen when money allows - but is certainly in the plans!)

No attacks on Greg from my stand - just kudos! I thinks he's fantastic to share all these design tips and tweaks on older gear with the folks who own that older gear. (I appreciate the time you spend sharing it with us too!!)

A person would have to be NUTS to attack such generosity!
Or have some kind of other agenda to do so ...

[hjames]

Absolutely!
Your system had the "passive only" network as shown here:

3141 schematic

Mostly, except the original owner had removed the biamp switch and put some extra wiring in there - I stripped that out and installed a second pair of 5-way terminals on the rear panel and ran copper lines directly from those to the woofers (were 2234s, now 2235). The main passive is the original circuit without the bass leg cap or inductor.

[pos]

Maybe I am wrong, but I think Rolf is now using a cable directly from the amp to the woofer, without using the binding posts of the speakers, and he says that makes the difference he is now hearing in the bass department when compared to his old biamp setup that was still using the internal cables of the speaker:

The direct cables from the amp to the woofer has resulted in a more accurate and more detailed sound.

[hjames]

Maybe I am wrong, but I think Rolf is now using a cable directly from the amp to the woofer, without using the binding posts of the speakers, and he says that makes the difference he is now hearing in the bass department when compared to his old biamp setup that was still using the internal cables of the speaker:

Oh god - Magic wire again ...

[Rolf]

Hi friends.

Maybe there is some confusion here. Here is my setup: Source (CD, DVD etc) into the pre amp. From the pre amp to the crossover, (JBL/UREI 5235) From the crossover to two separate stereo amps, where the left ch is going to the woofer (and yes, I have mounted binding posts for the woofer and to the CC network on the back of the speaker) and the right ch goes to the CC. On each side.

This is exactly the same way as it was before, with the original networks. The difference is that the internal/external switch and network is removed, and that has been an improvement for the reproduction from the woofer. And of course the CC network is much better than the original.

If somebody is interested I have the two original networks for sale.