Help power pair of Infinity Kappa 9's please


Hi all!
I have a pair of Infinity Kappa 9's:
Nominal Impedance: 4 to 6 ohm
Power Rating: 60-340 watts RMS
Efficiency: 102 dB SPL @1 watt, 1 meter
Crossover Frequencies: 80Hz, 800Hz, 4500Hz
Frequency Response: 29Hz-45kHz +/-3dB
Physical Attributes:
1x - SEMIT Supertweeter
1x - EMIT Tweeter
1x - 3" Edgewound Voice Coil Polydome Midrange Driver
1x - 5" Polypropylene/graphite Diaphram Polygraph
2x - 12" Cast Frame , L/C Tuned Woofers
Dimensions: 59.5"H x 21.5"W" x 8"D

My room is 12'x12', I have $2500 budget and would like to play music off my computer. I need amp(s), a preamp, and a DAC i guess (is the DAC necessary at my low of a budget range?). I know my budget is low so I will be shopping for very used/old equipment. If anyone has any experience, suggestions, or words of wisdom, they would be very much so appreciated.
Thanks,
JT
jtiesel2
Hi Jtiesel2,

I was serious about using a pro audio amp. I don't know all the specs of all the units out there but I do know of 2k+ watt units that will easily play @ 2 ohms that sell new well under $2k.

I've used QSC amps for over 30 yrs, so they must be doing something right. That's but one suggestion.

Seriously, good luck with your search.
The problem isn't power, its current capability. The Kappa 9's drob at one point down to .8 ohms. Most amplifiers will crap on themselves trying to drive a 1 ohm load. I have heard Kappa 9's sound decent on a 50 watt amp. Dave Cofin of the old Marcof lable made it by hand. It had a power supply that would put most 400 watt amps to shame and doubled its power down to 2 ohms. This amp might not play the party levels that you are talking about, but it could drive Kappa 9's without dying. Of course Power is nice and I would get what I could, but you need current capability. Find something that is at least 2 ohm stable and a ton of power and you will get a decent job until you push the amp into clipping.
Timlub is right on. Power is not an issue with the Kappas by and large. It's all about current, since the impedance drops ridiculously low. You need a very high current capability amp.

Tim, when I bought the Aragon, I looked at a Sumo Andromeda amp. The dealer recommended the Aragon, which was a bit cheaper than the Sumo, specifically to drive the Kappa 9's. Maybe he steered me wrong. But I'd still like to see the Andromeda drive these things at top volume for 30 minutes and not fail. I'd be pleasantly surprised. Just have a hard time believing a single Andromeda could do what a bi-amped configuration of an Aragon and Audio Research amplifiers could never come close to pulling off. Granted, Audio Research's solid state designs weren't that good (by AR standards), but they weren't exactly wimps, either....but the Kappas made them seem so. Furthermore, if these speakers could make an older Levinson amp cry uncle, well......
Timlub, since apparently you know about the speakers in question, what is the phase data? While <1ohm is wacky and phase at that impedance is probably just academic, I'm curious now.

What does anybody do, or HOW does any manufacturer justify this kind of bizarre load? And SERIOUSLY, what good is it?

I believe in system synergy and all that good stuff, but buying speakers which require owning stock in the power company AND an EE degree to find compatible stuff is beyond me.
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All that aside about the Kappa9 being amp killers and being poorly designed, I'm so enamored by them that I own four pair of them. If you put a killer preamp in front of them with a good source and the appropriate bi-amplification, you have yourself an outstanding speaker. They are not a speaker to own if you are not willing to amplify them properly. If you can amplify them properly, they are keepers for life. Big, beautiful and they sound outstanding when done right.

But, you can always ignore the naysayers here and try it for yourself and come to your own conclusion. If you try it and are successful, you should come back to this forum and post your findings. As a matter of fact, if you are not successful, you should post those findings also.
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