zobel vs impedance curve

[prickears]

Hi all,

Just looking for good advice.

Is it good form to XO @ a drivers natural rise of impedance if not using a zobel, or @ new impedance with zobel installed, or is it of no consequence?

Thanx, Mick.

[tinitus]

If you listen carefully you can hear when a zobel is right, or wrong
You need to try many combinations
To just mount any one and think its ok doesnt work well

[prickears]

Thanx Tinitus,

I'm not sure on this, however, does trying different zoble values shift xo point? Then is it a case of 'ballpark' both, (the xo and zobel), then work one or the other slightly one way or the other until it sings?


Cheers, Mick.

[SGregory]

tinitus,
If you would, please hint at what you listen for to determine it is right. I don't mean this question as a flame, I am curious what your opinion is.

[tinitus]

On the negative effects
I listen fore negative artefacts, mostly high frequency pitch
And blurred midrange
Small phase issues
And especially poor bass timing

Positive effects
Clarity
Good phase
Smooth natural sound
Easy on the ears
Good bass timing
Good definition
The last judgement is to have a relaxed feeling after long hours of listening
You should want to keep listening to music
Like if you simply cant get enough music
If you begin to feel stressed in any way, and want to shut it down, then its not good
Sometimes its really tiny tiny changes that makes the difference

Funny thing is that when the negative effects are avoided, the positive effects almost comes natural
Its kind of almost like it happens by itself, when it sound better WITH the zobel than without
The trick is to achieve improved clarity, and at the same time avoid any tendency to "tweetersound"
Voices should sound "full" with body, but not muffled and blurred
Almost like theres less distortion
When it works you will be able to listen to the most crappy music
And you will even enjoy listen to the news in radio, any kind of voices will sound like magic

My present speaker is made in a hurry, few days
Drivers just stand on the floor, on their magnets
15"/10"/2", just random speakers I had
You might call it omni-dipole
its not fantastic, but still quite enjoyable
Strange thing is that I cant play loud, but loose things close to the drivers still rattles a lot, when I try to play loud
Filter isnt perfect, but it works ok with the drivers

[CLS]

Hi tinitus,

Have you ever measured the impedance curves of your completed [zobel + driver combinations]? Are they flat?

[tinitus]

I really dont know, but it would be interesting to see measurements
I have this thing with measurements, I dont trust them
Its the same with carburator adjustments
My bike runs better when I quit measureing, and adjust by using senses, and a minimum of "logic" approach, like monitor the heat, listen to how it sounds, and feel how it rides
Not quite the same as speakers, but its close
It has to give you that pleasent feeling, wanting more, without stress
Its like meditation
And like with any other thing, you need to practice

But I have to admit, my amps drives Infinity Kappa9 with ease
They are 2ohm at low frequency, and known to shut down most amps
Nice knowing amps can take whatever comes
Good amps are important to do any of it

Well, maybe I took this too far, fore a simple question
But maybe the answer just cant be simple

But checking with measurements?
Sure, that would be fun
Learn how it looks like, and the throw it way again

[prickears]

I have heard that 'magic' your refering to, (Krix Lyrix, believe it or not, (don't LOL @ that) nothing I've ever heard comes close!).

Just not sure how to get it, y'see, the driver i'm working with is vifa's p22.

As far as I can work out it has similar response charactaristics to the p21wo-39-08, Although I don't have the testing gear to confirm this, I find that if i work to the p21s impedance curve - 40%, I get the best results.

My question is should the xo be worked out @ drivers nom impe if the zobel is designed properly?

Sorry 4 the dumb questions!

Thanx, Mick.

[tinitus]

Its not much info you give us, just a vifa p22

[SGregory]

Prickears,
You should start at the nominal impedance of the xover band. If your zobel brings you to the nominal impedance of the speaker the use the nominal impedance. It is much easier with a zobel since the impedance is flatter.

I will agree with tinitus, you will end up tweeking to find the sweet spot. What order crossover are you planning?

Testing gear is cheap (free if you have a okay soundcard) for impedance. Speaker Workshop, an amp, and a sound card. If you buy a mic (fully calibrated $100US, 50$uncalibrated) and a mic preamp(30$US) you can do freq measurements to help guide your decisions. Regardless how you do it it is fun trying to find the magic.