Zobel network

Having to build my own crossover, I have come across to tweak my crossover by adding a zobel network. From my understanding, a zobel network helps flatten the impedence curve of a speaker to nominal. With the impedence curve flat, the phase of the speaker comes close to in-phase or 0%.

Since this tweak is very simple, does anyone know of anyone of any speaker company that uses this network or have modified a speaker with a zobel network?

I know that Roy Johnson of Green Mountain Audio uses a zobel on most/all his speakers. I don't know whether or not he'll divulge the details.
2 other places I have seen zobel networks: printed manual from Partsexpress.com & on the Adire Audio website. In fact, on the Adire Audio website he has some equations & design procedure. Take a look there.
A 3rd place to look: Member "pjay" on AudioAsylum/SpeakerAsylum has his own speaker building site. He contributes regularly to that forum & you should be able to get some help from him.
Hope that this helps.
Merlin used to include external Zobel with some models.
Merlin uses a Zobel.

Dynauadio and Thiel have so many parts in their crossovers, despite a great deal of them being first order, that I would guess there is a Zobel in there.

Whether or not you actually need one is more the question. There are two schools of thought. Yes, you present a more flat impedance, and many feel the woofer or midrange "work" better. Others, including myself, go along with the no free lunch philosophy, seeing this manifested in additional crossover parts robbing dynamics and/or immediacy.

Whose side is right? Both, and neither. You can build a good speaker either way. Certainly, I hold the Merlins that Bobby builds in the highest esteem sonically. Our three way Frieds use a grand total of four parts in the crossovers, with no Zobel. Zobels are a lot more popular with those who implement series crossovers, such as in our Frieds, but we don't go with them. You may want to experiment, trying the circuit with and without it. My only caution is to make sure both the speaker and the coil and the resistor are all broken in to give you the most accurate snapshot as to whether or not the Zobel is your cup of tea.
Alfredo, are there gross anomalies in yr woof's impedance curve around the chosen x-over point that necessitate a zobel?? If not, live with the woof's inductance pattern. If yes, you're stuck with it! If you're adventurous, try the zobel both in front and behind the xover & choose the setting you prefer...
My Seas Odin speakers (rears) have a network across the two W18E001 magnesium cone woofers. Its purpose is to tame a well defined peak in the response of these drivers, just before they roll off. Away from this peak, the response is very flat, and the peak and the associated network to tame it is the penalty. Nothing comes for free! These drivers would have to be crossed over much lower if they were used without the network.
I am not a techie,but a real good amp designer in So Cal said a few months back,he does not like what they do in amps with regards to the sound coming out of the speakers.Just an opinion of course...Bob
Thanks for the responses. Gregm, judging the speakers T/S parameters, the impedence is up to 28 ohms at the crossover point with is 2500hz. At the point where the the impedence start to rise is at about 350 hz. At 1k, it has risen to 16.30 ohms.

So far I have the resistors but I'm still need the capacitors but don't with one to go. Electrolytic or poly caps?


The electrolytic is non-polarized. Sorry about the mis interpretation. Polarized electrolytic is a no-no. :)
Just tested the network today and notice an improvement in the midbass. As of now, midbass sound punchy and articulate. Their seem to be more control on the cone but I can't conclude on this since the components are not fully burn in.

Alfredo, use the cheapest caps to determine the optimum value. Since you're nearly (already?) there, one way of "burning in" caps is to charge and discharge them (outside the circuit of course) with ever increasing voltage until you reach ~90% their nominal value.
Sean's input would be useful here
Do any amps use a Zobel in their output stages?
Springbok, amplifier do use zobel network but it purpose is to stabilize current rail that supply power to the output stage during speaker loads. Using a zobel network in the woofer help sustain a near pure resistive load.