ESS AMT 1 impedance controversy...

Urloony · 18th February 2005, 12:24 AM

I have read here among the threads that the measured impedance of the AMT 1 series the "great heil" is about 4 ohms. However, I keep hearing about some AMT 1's that are 8 ohms. I have a pair of AMT 1's and the measured DC resistance is about 6 ohms. Is it possible to have a 4 ohm AMT with a measured DC resistance higher than it's impedance or do I in all likely hood have 8 ohm AMT's? I've included the original graph I found posted here. To add to the confusion I called Orange county speaker repair , who sell replacement ESS AMT diaphragms and asked them the impedance of the diaphragm. The sales rep said they were 8 ohm as listed in their computer. When I asked her if she could double check she spoke with a tech who said they are actually 4.
So what gives? There's also this ebay item that claims his AMT 1 is 8 ohms.

Gregm · 18th February 2005, 10:37 AM

Quote:

I've included the original graph I found posted here

Is there no way you can measure your amt1s? The impedance will be frequency dependant anyway and you want to know what it is at the chosen x-over frequency. The nominal value is an indication only...

The graph you attached shows impedance varying b/ween ~3,2-3,7 depending upon frequency, anyway, not 4ohm.
Cheers

JohnL · 23rd February 2005, 03:56 PM

Ahh... that explains the blip at 1200 that I can't seem to get rid of. I thought the fs was around 800. In any event, my Great Heils (from an AMT 1B - old diaphrams) measure 3.9 Ohms with a meter.

BTW, have any of you played with the Eton ER4s. I just got a pair and can't wait to try them in something.

John

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Impedance rate VS impedance stability	TomatoBangBang	Tubes / Valves	6	4th September 2008 10:46 PM
Has anyone been keeping up on the 'New Sensor' Controversy?	aletheian	Tubes / Valves	19	21st December 2005 10:17 PM
Need help understanding transformer impedance ratios and impedance matching	percy	Tubes / Valves	5	28th February 2005 08:35 PM
the DVD format controversy	Elkaid	Everything Else	6	10th December 2003 12:58 PM
The controversy	Peter Daniel	Chip Amps	76	11th July 2003 11:21 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

23rd February 2005, 03:56 PM	#3
JohnL diyAudio Member Join Date: Apr 2004 Location: Tampa, FL	Ahh... that explains the blip at 1200 that I can't seem to get rid of. I thought the fs was around 800. In any event, my Great Heils (from an AMT 1B - old diaphrams) measure 3.9 Ohms with a meter. BTW, have any of you played with the Eton ER4s. I just got a pair and can't wait to try them in something. John