2405...8 ohm vs 16 ohm

[gdwrench]

Here's the skinny....I just aquired a pair of slot tweeters, 2405's. I was led to believe when I purchased them that they were 16 ohm.The seller said he measured and they were 12 ohms,however when I recieve them and measure them I get 5.7 on one driver and 5.9 - 6.0 on the other respectively on my meter. Seeing is believing, they are 8 ohm.

I have done a search without much in the terms of definitive answers.The 2405 came in 8 and 16 ohm I know this much, what is the reason for 2 different impedences with the same 2405 # and most importantly, what was their applications for each exclusive impedence?? Which models would use 8 and which would use 16 and why ?? I need schoolin' here and this looks like a good place for it !! :D

[grumpy]

Sorry to be the one to challenge your assumptions :)

http://www.audioheritage.org/vbulletin/showthread.php?23869-075-2402-076-2403-2404-077-2405

[Mr. Widget]

The seller said he measured and they were 12 ohms,however when I recieve them and measure them I get 5.7 on one driver and 5.9 - 6.0 on the other respectively on my meter. Seeing is believing, they are 8 ohm.You are measuring DCR...he is talking about AC impedance. I'm not sure how he measured "12 ohms"... when measuring an impedance, you get a plot that shows the impedance over the range of frequencies that a driver will see... the number 12 or 8 or 16 are really averages and not exact figures.


Widget

[grumpy]

More reading:

http://www.audioheritage.org/vbulletin/showthread.php?11657-Changing-a-2405-Ohm-Rating

This question has been asked here -many- times, perhaps reasonably so.

If you find the impedance plots in the link above, you'll see that one can pick
8 ohms or 16 ohms or even 12 ohms depending on the frequency of interest
(typically in the neighborhood of the intended crossover frequency, so that
passive networks will work as intended...).

Short answer: no difference in use, with possibly audible differences in response
based on aging, abuse, care in diaphragm installation, and even stories of thinner
or differently alloyed diaphragm material in the older examples.

[gdwrench]

Sorry to be the one to challenge your assumptions :)

http://www.audioheritage.org/vbulletin/showthread.php?23869-075-2402-076-2403-2404-077-2405Thanks Grumpy...after I posted this yesterday I was doing some more searching through the website and found some threads stating basically the same info but it took awhile...Thanks guys

GD