[Sonny]

I have a few question regarding How to Install the Zoble network:

1) is the placement of the Resistor and Capacitor importance in terms of "should the Capacitor be connected to the (-) ground lead and the Resistor to the (+) signal lead or does it matter which way it is installed?

2) is it absolutely important that the Zoble (resistor and capacitor in series) be placed after the XO and before the driver terminals?  In otherwords, should it be place between the XO and the driver or is it ok to connect other leads from the other XO components to the Zobel, then to the drivers?

Thanks
T

[TomS]

My Merlins uses them on the outside of the enclosure on the binding posts, cap to positive.  Here is a picture http://www.merlinmusic.com/howto_sglwrg.htm

Not sure what you're trying to do, but be aware some amplifiers also have a network built-in.  It's beyond me to explain when to use it or not, and what exactly is happening, but it is likely very amp/speaker/cable dependent.  With Merlin, depending on what amp and cables you have, he recommends whether to use them or not.

Tom

[gstraley]

T,
   A couple of years ago I asked Rick Reimer from Reimer speakers this same question. He installs them on the circuit board. But when I asked him where the best spot to install them is he told me right across the +  and - of each driver. A problem you could run into doin it that way is if 2 drivers are wired in series together. Then the cap and resistor values would change for each driver. Install the speaker wires first and then install the Zobel network over the top of the wires. I an not 100 % certain of the second question. I was talking with an amplifier manufacture last month about a snubber circuit that is installed across the power supply caps of an amp. He mentioned to me to install the cap to the - (or ground) and connect the cap to the resistor and then install the resistor to the + side of the electrolytic cap. He mentioned to me that he listened both ways and it was obvious to him to install it this way. Is this the same for a Zobel network? I am not sure but this sounds like a similar type of scenario. + and -.

Gregg

[Sonny]

Greg and Tom,
thanks for your comments / advice....
Seems to me Greg, that the cap has to go on the (-) if it it is an electroletic cap, but since this is a sonicap, no polarity, they say it doesn't matter...also, I have talked to a couple of friends, and they say that as long as the zobel network is somehow connected to the leads that go from the XO to the drivers, that it doesn't have to be on the drivers's itself...
So, I guess I stay with what it's doing now, as I don't want to have to redo the who darn thing...
Unless, someone comes up with a definitive answer to my questions...
Thanks all!

T

[markC]

As long as you're using a film cap, (I hope you are!), with no + or - designation it doesn't matter how the cap & resistor in series hook up; it can either be cap to + & r to - or vise versa. It Does however matter where the zobel is installed. It must be after the xover, (in parallel with the output of the + & - of the xover), or on the + & - of the driver terminal.
For ease of assembly and appearance I put mine on the xover.

[Sonny]

As long as you're using a film cap, (I hope you are!), with no + or - designation it doesn't matter how the cap & resistor in series hook up; it can either be cap to + & r to - or vise versa. It Does however matter where the zobel is installed. It must be after the xover, (in parallel with the output of the + & - of the xover), or on the + & - of the driver terminal.
For ease of assembly and appearance I put mine on the xover.

I would assume that too, but I've been told by two good sources that it doesn't matter...So, if you look at my XO, does it matter if C3 and R3 ( on the midrange on the top XO, on the right) is also connected to C2 and L2 prior to going to the midrange???
 
and the same with R4 and C4 to L3 and C5?

[*Scotty*]

Sonny the electrical result will be the same whether the zobel is connected at the driver terminals or at L2 and C2. The zobel network compensates for the drivers inductance and stabilizes the impedance the crossover sees thus insuring that the driver rolls off correctly at the designed XO frequency. When you first posted the schematic I assumed that all network components like the zobels shown in the schematic were actually present in the circuit in the loudspeaker. Does the woofer have all of it's crossover parts present in the circuit as shown in the schematic?
When you have a series network all of the crossover parts and the drivers interact with one another to produce the final load the amplifier sees and the acoustic result you hear. Changing parts values or adding or deleting them affects how the speaker system as whole will sound.
Scotty

[Sonny]

Sonny the electrical result will be the same whether the zobel is connected at the driver terminals or at L2 and C2. The zobel network compensates for the drivers inductance and stabilizes the impedance the crossover sees thus insuring that the driver rolls off correctly at the designed XO frequency. When you first posted the schematic I assumed that all network components like the zobels shown in the schematic were actually present in the circuit in the loudspeaker. Does the woofer have all of it's crossover parts present in the circuit as shown in the schematic?
When you have a series network all of the crossover parts and the drivers interact with one another to produce the final load the amplifier sees and the acoustic result you hear. Changing parts values or adding or deleting them affects how the speaker system as whole will sound.
Scotty

Thanks Scotty...
Yes, everything is as described in the above XO schematic...I have recently gone back to the 4ohm tap on my tube amps and everythings is good...it was hot off the 8ohm tap...
I have been suggested to perhaps take the Zobel networks off the bass and mids and see how that effects the ability of the amps to drive the speakers...I was told that I will be surprised at the results and perhaps like it over the Zobels being in.  The idea is that with the Zobel's out, the speakers will be easier to drive for the amps...but I wonder what the impedance rise would sound like????

Tuan

[markC]

I agree with Scotty. If the zobel is connected @ the driver terminals, it's still connected to l2 and c2 and IMO doesn't make any difference. Now if it were connected b4 l2 and c2 it would definitly make a difference.