Correct tap 2 or 4 Ohm for the 1,7 Ohm curve
 

The Infinity Kappa 9.2i in extended mode with a minimum of 1.7 Ohm @ 30 Hz
( Could be 1.6 Ohm , that is What the Infinity manual says )

Please comment. Maximum impedance at 800 hz 5,6 ohms.

What Mac amp are you using?

Hi Charles, I use the MC2KW.

best regards Dag

I would use the 4 ohm tap. I don't like the 2 ohm tap on Macs. You have ample current with a 2KW, no question. I am not of the camp to impedance mismatch with Macs. If it sounds better with using an 8 ohm tap with a speaker with a 1.5 ohm minimum, you don't have a big enough Mac amp, IMO. So by severely stressing out the Mac amp you can create a larger amp, no question, but Mac does not recommend it and neither do I. It shortens the life of the amp. Off the 4 ohm tap I run an XVX with a minimum impedance of 1.6 at 326 Hz with nominal impedance of 4 ohms. My 1.25's rarely exceed 12 watts and never become hot even under very high sound levels. I am sure your 2K's will drive the Infinity's in a breeze with the 4 ohm tap and sound great. Check to see if they get really hot. I doubt they will.:yes:

Best Charles

Will you please explain what this means??

Correct tap 2 or 4 Ohm for the 1,7 Ohm curve
 

The technically correct tap would be 2 ohms. This is because the output impedance of the amp is lower using the 2 Ohm tap and the response will be flatter in the bass region where the impedance dip occurs.

Most people when trying the 2 Ohm tap do not level match the output with an SPL meter. Then the 2 Ohm tap sounds worse because the output level is lower. This is a common mistake.

Either the 2 Ohm or 4 Ohm tap will work fine.

I recommend making the level matched comparison and choosing the tap that sounds best to you.

Tom

Thank you Charles, interesting info and I currently use the 4 ohm tap. Will test the 2 ohm and see if I hear a difference.

Dag

Hi Tom, thanks! I will compare both 2 and 4 ohm taps and level match.

Dag :thumbsup:

Please let us know the results. I’m envious - those are great amplifiers you have Dag.

today 4 ohm testing
 

I can report that with the 4 ohm taps I had no trouble at all playing around 200-300 watts continuously with peaks close to 2000 watts. (no flashing power guard lights) I guess I am not at all close to the limits.
Will hopefully get to test 2 ohm tap tomorrow.
2 weeks ago we pushed a pair of Mcintosh XRT2.1k with MC1,2 and we saw both orange and red lights because we emptied the amp completely, peaking at 4800 watts and steady 1200 watts output. It was a big room.

Dag