Bi-amping of 4344 mkII using First Watt B4

[donjansson]

Hi there

Just traded in my JBL L300:s for a mint pair of 4344 mkII. They sound amazing with my Accuphase P-800, but I believe they may have more potential. I've heard a lot of people saying that bi-amping 43xx speakers made a huge improvement. A smaller Accuphase amp and the First Watt B4 might do the thing. What do you think? Do you know if there's any need of modifying/bypassing the internal cross-overs?

I live in the south of Sweden. However, I have a cousin in New York, who has helped me earlier with shipment overseas.

Thanks in advance
Oscar Jansson

 

[Zen Mod]

I believe there is decent amount of passive Eq in xovers , so that'll be important to emulate , whichever active xo you intend to use (have you sch to post here ?)

I'm just lazy to look for B4 (what's exactly) .......

however , I'm not overly impressed with Accuphase ..... having impression that JBL are deserving better amps

 

[Nelson Pass]

Here is a link to a network schematic and specs.

4344 Mk II network

You can use a simulator to get an idea of what those curves look like,
especially if you can model the equivalent to the driver. Not a trivial
exercise, but do-able.

The B4 is an active crossover, not an amplifier, in case there is confusion.
It is not capable of doing the 4 way 36 dB/oct the document seems to call for.

😎

 

[dotneck335]

Just traded in my JBL L300:s for a mint pair of 4344 mkII. They sound amazing with my Accuphase P-800, but I believe they may have more potential. I've heard a lot of people saying that bi-amping 43xx speakers made a huge improvement. A smaller Accuphase amp and the First Watt B4 might do the thing. What do you think? Do you know if there's any need of modifying/bypassing the internal cross-overs?

BiAmp (Bi-Amplification - Not Quite Magic, But Close) - Part 1

 

[donjansson]

How far will I come by just bi-amping "the regular way" without bypassing or rewiring? As for starters, I mean.

 

[donjansson]

"For the 4344MkII system, we chose our Charge-Coupled Linear Definition Dividing Network". - Manual for 4344 mkII

Are they already working with charge-coupled technology? There are slots on the back for 9V batteries. Therefore no need of a 9V bias modification?

"Additionally, the 4344MkII's dividing network allows for passive, bi-wire, passive bi-amp, and full active bi-amp operation. For the full active bi-amp mode, we recommend the use of a high-quality electronic crossover."

If it's possible to operate in full active bi-amp mode without eliminating the internal crossover, why should one remove it?

 

[donjansson]

The B4 is an active crossover, not an amplifier, in case there is confusion.
It is not capable of doing the 4 way 36 dB/oct the document seems to call for.
😎

I have a C-280L preamp. But thanks for clearing things out!

 

[macka]

Here is a link to a network schematic and specs.

4344 Mk II network

You can use a simulator to get an idea of what those curves look like,
especially if you can model the equivalent to the driver. Not a trivial
exercise, but do-able.

The B4 is an active crossover, not an amplifier, in case there is confusion.
It is not capable of doing the 4 way 36 dB/oct the document seems to call for.

😎

Hi Nelson

I actually measured the voltage drive and acoustic output of the 2123H mid range in this design and its overall a 12 db high pass slope.

The combined driver and LR network on the driver is 6db slope while the series capacitor adds the 2nd pole.

The woofer is a 2nd order filter

So the B4 could be set up for 2nd order low Pass and 1st order high pass it should be close to the passive crossover.

I plan to try with my B4 and will provide follow up