Re: so what's the value of "nominal impedance"? any meaning? - Jon Risch

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Re: so what's the value of "nominal impedance"? any meaning?

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Posted by Jon Risch on November 2, 1999 at 20:40:43

In Reply to: so what's the value of "nominal impedance"? any meaning? posted by klaus on November 2, 1999 at 10:02:42:

Nominal impedance is always based on just the drivers themselves, not with added impedance or crossover elements added. In that respect, most drivers come close to the rated nominal, and what with the typical need for padding for a lot of tweeters, the impedance of tweeters that get padded can end up higher than the raw driver.

Using a Zobel usually ends up with an impedance curve in the upper ranges that comes close to the DCR of the tweeter. If a conjugate for the resonant frequency is used, then the overall Z will end up in the realm of the DCR if maximum flatness is the desired goal.

I think that too much emphasis is placed on getting the Z curve super flat, instead of keeping in mind what exactly was trying to be accomplished by the use of the various networks.

For most crossovers, use of a Zobel is NOT required for proper crossover operation, as the inductive rise does not occur until beyond the range of the crossover point. However, it can help make the tweeter load a bit more consistent, and help maintain crossover function a little better. In my mind, the main reason to use the Zobel on a tweeter, is to damp the resonance that occurs in the HF due to the tweeter voice coil inductance resonating with the series crossover cap. The resonant lift that occurs above about 10 kHz can sound 'better' than a non-resonant output, but it is NOT accurate, and can cause the user to seek dull sounding cables and electronics to alleviate the HF resonance of the tweeter.

I know this is America, but more is NOT always better!

Jon Risch

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Follow Ups Full Thread

Topic - Zobel networks - TA 12:48:09 11/01/99 (13)

Re: Zobel networks - Dave Ingels 10:02:33 11/02/99 (2)

Re: Zobel networks - Jon Risch 20:23:05 11/02/99 (1)

Re: Zobel networks - Dave Ingels 21:12:10 11/02/99 (0)

Re: Zobel networks - Mart 14:22:05 11/01/99 (9)

then another question on zobels - klaus 04:08:13 11/02/99 (8)

Re: then another question on zobels - Paul Joppa 21:20:02 11/02/99 (0)

welcome to the mysterous world of raw drivers - Mart 06:36:11 11/02/99 (6)

so what's the value of "nominal impedance"? any meaning? - klaus 10:02:42 11/02/99 (5)

Re: so what's the value of "nominal impedance"? any meaning? - Jon Risch 20:40:43 11/02/99 (1)

Kudos! - Mart 22:47:26 11/02/99 (0)

Re: so what's the value of "nominal impedance"? any meaning? - Mart 13:21:34 11/02/99 (2)

Re: so what's the value of "nominal impedance"? any meaning? - klaus@mchugh.ru 00:47:21 11/03/99 (1)

Re: so what's the value of "nominal impedance"? any meaning? - Mart 18:15:48 11/03/99 (0)

Follow Ups

Re: so what's the value of "nominal impedance"? any meaning? - Jon Risch 20:40:43 11/02/99 (1)

Kudos! - Mart 22:47:26 11/02/99 (0)

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