15ohm for the early, 11ohm for the later. But as you say, as usual with nominal ratings, you can take that for what it's worth. This is the system impedance of the Falcon Gold Badge LS3/5a, which is essentially a brand new mid '70s 15ohm nominal LS3/5a:
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Frequency range is where the music is - from 16 Hz to 20 kHz, i.e. where loudspeaker can work. Why would we need impedance at 2 Hz?
Minimum impedance is occurring above driver resonance (Fs) and, if vented, at the port tuning frequency (Fb).
I didn't say it is 8-ohm loudspeaker, it seems to me it is 6-ohm nominal. Drivers Rdc are higher than typical 4-ohm drivers.
Yes. That's what I was ready to think too...
An 8 ohms Woofer is usually around 5-6 Ohms DCR.
T
Sure you can, just like things were always done before dats, but why? Its the convenience.
Completely of topic, but to demonstrate how dats solved one issue. I was experimenting with step up transformers, to create preamp based on buffer and transformer...just like frontend in m2 or vfet or zen mods iron pre.
Measured various transformers, some had lots of distortion, some were clean. I had ikido tube buffer sitting in the drawer, i assume tube buffer driving step up buffer would work well...but it did not. Dats to the rescue, i used dats to measure input impedance sweep of step up trafos and it was dipping too low below 100hz. Tube buffer failed to drive it, solid state had no problems. Just a side note how i used dats.
In other thread it showed easily which tweeter had oil in the gap and which did not. Sure you can do all this with simple jig, but dats is convenient, done in seconds and data are neatly stored in the same folder for future comparison.
Measured various transformers, some had lots of distortion, some were clean. I had ikido tube buffer sitting in the drawer, i assume tube buffer driving step up buffer would work well...but it did not. Dats to the rescue, i used dats to measure input impedance sweep of step up trafos and it was dipping too low below 100hz. Tube buffer failed to drive it, solid state had no problems. Just a side note how i used dats.
In other thread it showed easily which tweeter had oil in the gap and which did not. Sure you can do all this with simple jig, but dats is convenient, done in seconds and data are neatly stored in the same folder for future comparison.
Anothe side note, sorry.
Most of my speakers are 8 to 16 ohms. If i am bulding mtm, and have choice to make two midbasses what impedance i want, i go for two 8 ohm in series. Not in parallel. Only if 8 ohm not available i make two 4 ohm in series. Never two 4 ohm in parallel. Sure it would sound louder, but...
Every amplifier spec, classA more, but even classAB, have increasing distortion with decreasing impedance of the speaker. In some cases its dramatic, like ten fold in distortion increase. So you get lowder more distorted sound with low impedance. If thats what you want, fine with me. I like 8-16 ohm speakers.
Most of my speakers are 8 to 16 ohms. If i am bulding mtm, and have choice to make two midbasses what impedance i want, i go for two 8 ohm in series. Not in parallel. Only if 8 ohm not available i make two 4 ohm in series. Never two 4 ohm in parallel. Sure it would sound louder, but...
Every amplifier spec, classA more, but even classAB, have increasing distortion with decreasing impedance of the speaker. In some cases its dramatic, like ten fold in distortion increase. So you get lowder more distorted sound with low impedance. If thats what you want, fine with me. I like 8-16 ohm speakers.
That's a bit of a goal post change there adason. So what's behind all this enthusiasm?
Ok, you got me.
I appologize to presscot for suggesting dats. Forget dats, use signal generator, plot the data old fashioned way, and post here. Measure each speaker around its range of requencies, especially Fs. Then measure complete speaker including crossover with frequency sweep and post the data. Forget your multimeter dc resistance. Thats just wrong. Do you listen to dc signal or ac signal? Music is ac signal. So measure your speakers with ac not battery. Post the impedance sweep with signal generator, then we can discuss what impedance your speaker is.
I appologize to presscot for suggesting dats. Forget dats, use signal generator, plot the data old fashioned way, and post here. Measure each speaker around its range of requencies, especially Fs. Then measure complete speaker including crossover with frequency sweep and post the data. Forget your multimeter dc resistance. Thats just wrong. Do you listen to dc signal or ac signal? Music is ac signal. So measure your speakers with ac not battery. Post the impedance sweep with signal generator, then we can discuss what impedance your speaker is.
AllenB, if presscot is going to post impedance sweeps done your way with simple jig, each speaker separately and final speaker with crossover, i will send you $100.
I feel that about half of the new threads in this forum are the OP refusing to get an impedance measurement tool (DATS) or making one himself for use with Room EQ Wizard. OP, take the plunge man. Measure your impedances of your driver, simulate your crossover in XSim and all your answers will be staring you in the face.
Also, if you are curious about how complicated driver impedance is, download a spec sheet from ScanSpeak, at the bottom there's a schematic which shows the electrical equivalent formula for a free-air driver. Then you can plug in all the numbers and use something like XSim to simulate the driver electrically. The DC resistance (Re) is shown and you can see why the driver impedance is / is not Re. Lastly, maybe look more at a few dozen Stereophile speaker review metrics about how big a difference there may be between what manufacturers claim and what they measure.
Another alternative is to get some driver files (FR and ZMA) from Dayton for instance and built up a 2 or 3 way virtually in XSim. Then you can explore questions like this virtually.
Also, if you are curious about how complicated driver impedance is, download a spec sheet from ScanSpeak, at the bottom there's a schematic which shows the electrical equivalent formula for a free-air driver. Then you can plug in all the numbers and use something like XSim to simulate the driver electrically. The DC resistance (Re) is shown and you can see why the driver impedance is / is not Re. Lastly, maybe look more at a few dozen Stereophile speaker review metrics about how big a difference there may be between what manufacturers claim and what they measure.
Another alternative is to get some driver files (FR and ZMA) from Dayton for instance and built up a 2 or 3 way virtually in XSim. Then you can explore questions like this virtually.
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Yes, I took the measurements in the meantime. But I haven’t measured the entire speaker.
That won't show anything meaningful - it will be the sum of woofer Rdc plus low-pass filter (woofer) inductor Rdc.
The correct way is to measure impedance vs frequency (20 Hz - 20 kHz) of the whole loudspeaker, but with REW, ARTA, ...
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