Zobel network for Heresy

[DokSoul]

I'm intereted in possbily adding a zobel network to my K22E woofer. The Zobel flattens out the impedance curve at higher frequencies for the amp. I believe that this is supposed to result in better mids before crossing over to squawker and better loading on the amp. I'm tentively planning on adding a 8 to 10 ohm, non-inductive resistor in series with the 33uf cap across the speaker. I'd like to know if anyone else has done this and what your experience, results are? If no ones done it, does anyone know the Re and Le for the speaker, knowing that I'll calculate values to make sure I'm doing it right. Later after I apply the mod, I'll post my subjective results. Help please?

As you can see on my system below, I'm quite willing to do small project tweaks!

My Home Theater System:

Pioneer Elite THX VSX-24 Receiver

Magnavox CD B586, 6 disk pioneer cartridge

Replaced 100uf audio board caps with 1000uf

Replaced LM833 op amps with OPA2604P

Panasonic RV-80 DVD

Unit is suspended on ½ sphere racquet balls and sand bags on top

Klipsch original Heresy mains

Use ChrisV Cat5 speaker cable

Horns have been rope caulked

Replaced internal caps with Zen polyprop

Added ½ bat of RS acoustic insulation

Replace woofer bypass cap

Each spiked with 4 pyramid lead fishing weights held with blue tac - no drilling. Sandwiched between bottom: 18" H x 15" diameter stump; and on top: 20 lbs concrete cylinder in wood cradle

Klipsch KSF C5 center

Sits on TV cabinet, but isolated with 8 sorbothane ½ spheres

Klipsch KSF 3.1 rears

Mitsubishi 12" sub 120 watts

40 lbs of concrete cylinders hold it down

[WMcD]

I think a Zobel is not warranted in this situation.

My observation is that Zobels are used to counteract the rising impedance of the woofer voice coil. At higher frequencies the inductance of the voice coil has an effect. Let me say that is typically starting at around 1000 Hz.

The largest reason for the use of a Zobel is to keep the impedance of the woofer predictable so that a low pass filter can be designed. It doesn't improve frequency response without crossover design considerations. Again, it only makes impedance more predictable and flat.

In some speaker designs, the cross over to the midrange or tweeter is at 1000 Hz or well above. And this is in the area of rising impedance of the woofer. So Zobels make some sense.

However, the cross over to the midrange in the Heresy is well below 1000 Hz. Therefore, a Zobel isn't going to help.

The other issue is whether the Heresy needs a "better" or different woofer crossover. Right now, to my understanding, it has its own single order 6 dB per octave inductor. If you're going to "improve" with a 12 dB per octave cross over, it is going to take more work than just a Zobel.

Gil