Howdy Folks:
My Christmas list includes new subwoofers for my 02 XKR conv. I would really like matching impedances for maximum power transfer. I am considering Kicker 10 CVT65's which are available with 2 or 4 ohm impedance.
However, during my searches, I have found nothing conclusive as to what this amplifier's output impedance is. I have read that some figure that 4 ohms is safer than 2 or 4 is better than 2 (Thus far,I have found neither of these claims to have any evidence to convince me}. For the most part, I am seeing more installations with the 4 ohm version and indeed, if the amp is 4, then I will be happy to go with that. On the otherhand, if the output is 2 ohms, then, I cannot see wasting power in the amp that is not allowed to reach the subwoofer.
Any help is appreciated. As a last resort, I would go with the 4 ohm based on the good results that others have had.
Thanks

 

Nice present. Good for you.

If you knew the amp impedance, of course, you could just match it. Not knowing that, 4 ohms is the safer bet. Short-hand reason is that if the amp and speaker impedances are not equal, then more power is dissipated in the one with the higher impedance. We would want that to be the speaker, not the amp.

If you Google "Thevenin's theorem" you'll see how to calculate the power dissipated in the amp and in the load for any combination of impedances.

Good luck.

[edit: forgot ... The lost-power penalty if we guess wrong -- if the amp is 2 ohm but we select a 4 ohm speaker -- is really small. It works out to be only one part in nine. So if we would have had a max of, say, 45 watts available with a 2 ohm speaker, we have 40 watts with a 4 ohm speaker. Not so bad.]

 

The factory subs are 2 Ohms on the Alpine premium system.

 

Howdy Dennis and Eagle:
I just came in from church and ran the numbers for 1,2, and 4 ohm speakers with a 2 ohm amp. (just assuming a single frequency, I don't want to get too technical as it has been over forty years since I was in tech school and have never worked in that capacity. ( I am very rusty...solid state was still new then!) Anyway, I'm in complete agreement with you. Calculating for a 1 ohm speaker also yeilded the same 1/9 drop, but at twice the current draw through the amp output.
Thanks for the refresher and bringing me to agreement.

Eagle, where did you find the 2 ohm rating? I have been looking everywhere for it?

 

My 01 is 2ohm, just replaced them last month.

 

Thanks all
I feel confident now with the 2 ohm speakers on my Christmas list.

 

I've done pretty extensive research here and have found 2Ω seems to be the consensus between people that actually found a value. There are several people using 4Ω just to be on the safe side. I'm planning on this same mod next spring/summer and I'm going with 2Ω.

 

Found it out when I changed them out:https://www.jaguarforums.com/forum/x...m-4-ohm-41280/
Hope that helps.