Need Impedance Meter suggestions

[e.lectronick]

Hi, folks
I've just been building my first set of speaker enclosures according to a friend's recommendations, and I need to get a decent impedance meter that won't cost me an arm and a leg.

Does anyone have any suggestions for which models to watch for?

Also, are there any alternatives to purchasing a meter? Can I rig up/use my Digital Multimeteror or Oscilloscope to test impedance?
-Thanks for any suggestions.
-Erik.

 

[Centauri]

Impedance will vary quite considerably with frequency, so if you want to plot the impedance curve for your speaker then I suggest you put your PC to use. Download Speaker Workshop (free), build up Wallin's impedance jig, and you're all set for very little outlay.

Cheers

 

[wintermute]

I'll second that suggestion

And go and check out Claudio's speaker workshop tutorial too!

http://planeta.terra.com.br/educaca...onegro/english/

and don't be impatient like me and start doing stuff before you have set it all up properly

regards,

Tony.

 

[wintermute]

Hi Centauri,

You mentioned in another SW thread I started, about a mic preamp linked to from the speaker workshop site, but I can't find the link Do you have it?

I've ordered some WM-60AY mics from digikey, so I'll hopefully be getting some proper testing done after Christmas.

Regards,

Tony.

edit: Erik, there are two versions of the walin jig here is a link to the newer one http://www.gti.net/wallin/audio/jig2/jig2.html I bult the first one but I'm going to redo it I think.

 

[Centauri]

Hi, Tony

Sorry, it wasn't linked directly from there but is on Eric's site - Old version preamp at http://www.gti.net/wallin/audio/preamp/preamp.html and newer version at http://www.gti.net/wallin/audio/preamp2/preamp2.html

I built the older vrsion, and it works fine.

Cheers

 

[wintermute]

Thanks Centauri,

I found those yesterday but wasn't sure if they were the ones. I'm kicking myself I didn't ask about this before I ordered my mics, as the opamp in the second preamp I can only find at farnell, and it's about $6 more than if I had have included it in my digikey order, would have made the $17US postage that bit more worth while ... Oh well.

Did you use veroboard/matrix board, or did you make a pcb? I've never made my own pcb's maybe time to give it a try.

Oh and that link I put in for Claudio's web site is broken (cut and paste didn't work......

It should be: http://planeta.terra.com.br/educacao/claudionegro/english/

Regards,

Tony.

 

[Centauri]

I used veroboard, and built the thing into an unused pro dynamic microphone housing - a battery compartment and jack socket (with battery switching) where the grille used to be, and a RCA socket at the normal connector end that my mic and long brass tube plugs into. This allows me to use the setup in a normal mic stand (although backwards), and keeps low level signals short. I used the original mic's on/off switch as the gain switch, however due to this being large and right in the middle of the area involved, I used 2 dual opamps instead of the single quad opamp - just made it that much easier to jam it all in...

Cheers

 

[wintermute]

Thanks Centauri. Think it's time for me to start ordering some bits

Regards,

Tony.