Ohms?


Can some please explain speaker ohms to me? As I understand it a speaker come rated at a particular ohm-lets say 8. I understand the lower the number the more efficent is??? What I am having trouble with is the minimum rating. Does the ohm rating change on a speaker? Help!!!
vongwinner

Showing 2 responses by jim

Great thread and great explanations. However, ohm's are important even with modern solid state equipment and it's not so much to do with exotic tube equipment. Not nominal imedance, but IMEDANCE CURVES. In the real world, this is what drives amps (yes, solid state amps) nuts. I've been on the planar/ribbon/electrostatic road for quite a few years and what makes amp matching so critical for these puppies is the impedance swing (impedance minima at high frequencies combined with higher impedance in low frequecies). Lots of people fret impedance dips but this isn't such a big deal since these occur at high frequencies and there isn't a lot of energy going on there. It's how an amp responds to the dips combined with what goes on in the lower mids that really counts. The Newforms have a curve of 2ohms to 100ohms, I think. If you were an amp tring to play dynamic music with lots of fast changes in impendance you would be working your proverbial ass off to keep up with a curve like this. My speakers (CLS's) are tame by comparison... 1.5 ohms to 35 ohms in the mids. (One version of my speakers dropped down to .6 ohms!) Most speakers rated at a nominal 8ohms have far less swing -- usually less than 6ohms in either direction -- making the amp's job easier. The type of music (degree of dynamics and low frequency extension) also makes a big difference in an amp's ability to keep up with the swing. Again, great explanations of terminology that's thrown around and not fully understood in real world applications. Thanks for bringing it up.
I agree with you in general. But when I was an audio pup, I decided that I really liked those flat speakers with the ribbons on them. I'm not a technical person and picked up what was relevant along the way out of necessity. (Boy, did I make some mistakes.) Whe you get down to it, impedance curves (simply minimun and maximum) are not too complicated and might help in choosing an amp for speakers that don't have coventional loads. And today this doesn't seem to be limited to ribbons and electrostatics. But I agree that most people will go with speakers for which impedance swing is not an issue. No harm, no foul. Have a good one.