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Post by generalkorrd on Mar 20, 2015 19:48:13 GMT -5
Ok, I have an opportunity to get a pair of Infinity Kappa 9's(first run). I have UMC1/XPA2. I know that the speakers are amp destroyers, and I have heard that Adcom gfa 555's are good enough. I know that the XPA2 is head and shoulders above the Adcom. Question is: will these be a good match? Will I get the full performance out of the 9's? Who has run these with firsthand experience? I have heard that the 9's just don't sound very good unless you have enough amp. Personally, I feel I have more than enough amp in the XPA2, but I really would like some firsthand knowledge. I'm planning on closing the deal tomorrow, so any fast advice would be helpful.
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Post by Dan Laufman on Mar 20, 2015 20:09:41 GMT -5
You should be well served with the XPA-2. Enjoy!
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Post by generalkorrd on Mar 20, 2015 20:12:38 GMT -5
You should be well served with the XPA-2. Enjoy! A yes from the man himself! This is good news, I have been lusting after Kappa 9's since the mid 90's, but never had the right amp, or enough room, or enough money. Now it has all come together and I just don't want to be disappointed. Thanks |
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Post by RichGuy on Mar 20, 2015 21:32:24 GMT -5
Great speakers, the Infinity Kappa 9's are speakers I lusted over in the 90's as well. If you do get them let us know how they work out.
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Post by seppo on Mar 20, 2015 22:24:43 GMT -5
I am driving Infinity RS-II's (nominal 3 Ohm speakers, dipping down to 2 Ohm extensively) with SA-250 (clean 400 wpc at 4 Ohm), and the combo works great, just pure music at any volume level.
If you go to Audiokarma Infinity forums you will find some people complaining that their high-end Infinity's put XPA and earlier Emo amps in protection. All I know is that SA-250 works great. Although Kappa 9's are even more difficult load, dipping down to 1 Ohm occasionally.
Bottom line: If you have a chance to get reasonably priced Kappa 9's in good shape, absolutely go for it. XPA-2 will certainly get you going, although most people routinely bi-amp the 9's for best results. But upgrading the amplification in future is what makes this hobby fun. The Kappa's have almost unlimited potential..
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Post by generalkorrd on Mar 20, 2015 22:52:49 GMT -5
I also have a pair of Soundcraftsmen pm 860's that I can use to biamp with, and I have personally seen and heard those amps play music through the transistors with the speaker leads deadshorted, so they can handle any load I care to put to them. I would prefer to keep those for my sub amps, so I'll see how the XPA does first.
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Post by Dan Laufman on Mar 20, 2015 23:30:05 GMT -5
You should be well served with the XPA-2. Enjoy!
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djreef
Sensei
Thoroughly enjoying my Schiit
Posts: 353
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Post by djreef on Mar 26, 2015 13:19:40 GMT -5
Is there an echo in here?
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Post by vcautokid on Mar 26, 2015 13:34:13 GMT -5
Yes, love the Kappa speakers. The XPA-2 will great with them. The XPA-2 is legend putting the power to speakers That are hard to drive. Maggie's, Martin Logan's, it does well.
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Post by generalkorrd on May 30, 2015 14:29:44 GMT -5
Well, here is an update some of you may not like. Trying to drive the Kappa's with an xpa2 is a no go if you want to get any decent volume out of it, and that's with the Kappas on normal. Don't even try extended. Even if I biamp the Kappas with one of my old Soundcraftsmen and the xpa-2, I cant put the xpa-2 on the woofers, only on the highs. That's a little overkill dontcha think? Apparently, an amp that weighs half as much and is 20 yrs old is what it takes to drive these things. I bought a Carver TFM-55x and it rocks these things.
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Post by Boomzilla on May 30, 2015 15:20:22 GMT -5
The Kappa 9s were one of the best three speakers Arnie Nudell ever built. The Beta & the IRS were the other two. That said...
The woofers used foam surrounds. These tend to stiffen, become brittle, and fall apart. Before they die, the stiffness makes the woofers change their Q considerably. The things weren't easy to drive with flexible surrounds - with stiff ones, they become impossible. What's the condition of the surrounds?
The Infinity ribbon tweeters also were plagued with delamination (?) problems.
A neighbor of mine, Mr. Russel Coco, is one whom I consider an expert on Infinity products (he's owned everything in the lineup - multiple times). He specializes in re-coning the woofers & repairing Infinity tweeters.
Now any set of Infinity 9s in decent condition should rock out with an XPA-2. You may not be able to drive them to auditorium levels, if that's what you're looking for, but it should be an excellent match. If you're not getting what you want from the 9s with the XPA-2, then either you're asking the speakers to play more loudly than they really want to (and with the 9s, that's not so loud as you might think) OR your woofer surrounds are due to be refreshed.
How to tell? Run your finger gently over the surround. Does it feel sticky at all? Stickiness is what happens before they become brittle, and is itself an indicator of the surrounds being seriously past their prime. Poke the surround gently with your finger. If the indentation stays briefly before popping back out, the surrounds are getting brittle. Needless to say, if the surround breaks (or your finger pokes through)...
Lastly, don't assume that the XPA-2 is overkill for the Infinity mids or tweets either. Those drivers are POWER HUNGRY. Not only are they low impedance, but the crossovers are power suckers too.
I've heard IRS, IRS2, Betas, and Kappas of many flavors (including the 9s) at Russel's house. He's run them on a variety of amps - his favorites are Electron Kinetics Eagles on the bass drivers, and whatever he has on hand for the midranges and tweeters. Also, the mounting screws for the Infinity drivers had a tendency to loosen themselves on Russel's speakers, if I remember right. Make sure the drivers are tightly mounted to the cabinet.
Therefore, before you say that the XPA-2 wimps out, check the condition of your drivers.
Cheers - Boomzilla
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Post by generalkorrd on May 30, 2015 16:45:30 GMT -5
Well, the drivers were refoamed recently, and the foam is nice and pliable. All the tweets are in excellent shape and sound great. To be honest I probably do want the 9s to do more than they can with the xpa2 alone. Not all the time, but when I want to rock out, I don't want my amps shutting down. With the xovers on normal, the xsp1 on direct, the xpa2 driving the 9's full range, the amp shuts down at around -14 to -8 depending on material. With the xovers on extended, the amp shuts down at around -18to -12. That's not as loud as you may think. Its ok loud, small 10 person party loud, but not rock my face off auditorium loud at all. The 9's can get stupid loud off that Carver I just bought, I took it to +4 on the xsp1 before I HAD to turn it down lol.
Now get this. I just hooked up the xpa-2 to my 2 15" diy subs ported to 22 hz. These subs are dvc4. I wired them parallel to the xpa-2, so 2 ohms per channel. Works great. The Carver is running full range to the Kappa's and the Xpa is running my subs and the system wasn't breathing hard at -5 on the xsp1, with the same material that shuts the xpa2 down as stated above. I have heard the Kappa's drop to .9 ohms at certain freqs. Im having a hard time believing that the subs I have wired to 2 ohms per channel don't drop at least that low. Weird right?
I only say the xpa is overkill for just the mids because I have never been in a position where I had to use such a large amp for 3 tweeters and 2 mids. These Kappa's are my first true "high end" speaker.
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Post by generalkorrd on May 30, 2015 17:20:06 GMT -5
It also sucks that Dan himself said Ill be good, and now I have to ship the Xpa in for repairs that it probably doesn't even need and wont get. Itll get checked, Ill get told that the amp benches perfectly, and Ill have wasted quite a few bucks on shipping to be told all that. As big and heavy and well built that the xpa is, It should not have a problem running those Kappa's, especially when I can run them with the Carver tfm55x.
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Post by Boomzilla on May 30, 2015 17:41:52 GMT -5
The Carver amps were intended to run stupid loads. The Apogee ribbon speakers, if I remember right, presented virtually dead shorts at some frequencies. The Carver amps drove those AND the early Carver speakers that also had low impedances. In short, the Carver amps were designed to be "welding machines" if necessary. The Emotiva amps aren't. This isn't to say that the Carvers were "better" amps, per se, but only that they could tolerate impedances that most amps can't.
My gut feeling is that you're absolutely correct - there's nothing wrong with your XPA-2 except that you're running out of the design envelope with those Kappa 9s. Note that at reasonable levels, Mr. L is absolutely right - the Emotiva amp drives the speakers fine. It's only at the volumes that you're asking that the amp shuts down to protect itself.
Now that said, it is also possible that:
1. Due to manufacturing variances, your Kappas have slightly lower than design impedance and/or
2. Your particular XPA-2 may have overly sensitive protection circuitry
But I'm just speculating... Mr. Laufman or Lonnie might wish to comment more authoritatively.
Best of luck!
Boomzilla
PS: If you want "welding machine" amps, and at reasonable cost, look at "pro" power amps. I've had Yamahas, Peaveys, and Crowns that could drive short circuits without damage and still with LOTS of current output!
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Post by Boomzilla on May 30, 2015 17:59:18 GMT -5
...Now get this. I just hooked up the xpa-2 to my 2 15" diy subs ported to 22 hz. These subs are dvc4. I wired them parallel to the xpa-2, so 2 ohms per channel. Works great. The Carver is running full range to the Kappa's and the Xpa is running my subs and the system wasn't breathing hard at -5 on the xsp1, with the same material that shuts the xpa2 down as stated above. I have heard the Kappa's drop to .9 ohms at certain freqs. Im having a hard time believing that the subs I have wired to 2 ohms per channel don't drop at least that low. Weird right?... It isn't necessarily the minimum impedance, it's the RANGE of that low impedance. Your subs may drop to the the same minimum as the Kappas, but in a much narrower frequency range. Amps tolerate narrow width dips more elegantly than broader range ones. It's also possible that your subs hit their minimum at a frequency that isn't driven hard. The Kappas may have their minimum at a frequency right in the middle of the audio range. Again - just speculating... Boom |
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Post by generalkorrd on May 30, 2015 18:35:31 GMT -5
...Now get this. I just hooked up the xpa-2 to my 2 15" diy subs ported to 22 hz. These subs are dvc4. I wired them parallel to the xpa-2, so 2 ohms per channel. Works great. The Carver is running full range to the Kappa's and the Xpa is running my subs and the system wasn't breathing hard at -5 on the xsp1, with the same material that shuts the xpa2 down as stated above. I have heard the Kappa's drop to .9 ohms at certain freqs. Im having a hard time believing that the subs I have wired to 2 ohms per channel don't drop at least that low. Weird right?... It isn't necessarily the minimum impedance, it's the RANGE of that low impedance. Your subs may drop the the same minimum as the Kappas, but in a much narrower frequency range. Amps tolerate narrow width dips more elegantly than broader range ones. It's also possible that your subs hit their minimum at a frequency that isn't driven hard. The Kappas may have their minimum at a frequency right in the middle of the audio range. Again - just speculating... Boom I can see that. I also understand about pro amps. In my sig are two of some of the better ones from the 80's. One will drive the Kappa's, but they go into clipping somewhat later than the Xpa, but you can hear them running out of steam right around the -10 range on the volume control. I think its also a matter of being able to deliver an obscene amount of current which the carver is able to do, and the xpa SHOULD be able to do but for its protection circuit. |
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Post by seppo on May 30, 2015 23:12:19 GMT -5
Well, the drivers were refoamed recently, and the foam is nice and pliable. All the tweets are in excellent shape and sound great. To be honest I probably do want the 9s to do more than they can with the xpa2 alone. Not all the time, but when I want to rock out, I don't want my amps shutting down. With the xovers on normal, the xsp1 on direct, the xpa2 driving the 9's full range, the amp shuts down at around -14 to -8 depending on material. With the xovers on extended, the amp shuts down at around -18to -12. That's not as loud as you may think. Its ok loud, small 10 person party loud, but not rock my face off auditorium loud at all. The 9's can get stupid loud off that Carver I just bought, I took it to +4 on the xsp1 before I HAD to turn it down lol. Now get this. I just hooked up the xpa-2 to my 2 15" diy subs ported to 22 hz. These subs are dvc4. I wired them parallel to the xpa-2, so 2 ohms per channel. Works great. The Carver is running full range to the Kappa's and the Xpa is running my subs and the system wasn't breathing hard at -5 on the xsp1, with the same material that shuts the xpa2 down as stated above. I have heard the Kappa's drop to .9 ohms at certain freqs. Im having a hard time believing that the subs I have wired to 2 ohms per channel don't drop at least that low. Weird right? I only say the xpa is overkill for just the mids because I have never been in a position where I had to use such a large amp for 3 tweeters and 2 mids. These Kappa's are my first true "high end" speaker. The magnitude (i.e. the real part of the full complex impedance) of Kappa 9 impedance curve looks like this:  I have not seen any measurements showing the phase of the complex impedance, but if the phase is substantially non zero (as I remember reading somewhere), like in the case of may electrostatics, the resulting load is even more difficult for the amp (since the load is not anymore purely resistive, rather than the speakers show up e.g. as a massive capacitor for the amp). I could guess that your subs have relatively simple crossover, and present a relatively straightforward resistive (low impedance, but with nearly zero phase angle) load to XPA-2. While Kappa 9's dip down to 0.8 Ohm, and have stronger phase difference, thus presenting a load with higher reactance that the XPA-2 can not anymore handle... |
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Post by generalkorrd on Jun 18, 2015 14:19:47 GMT -5
My quest to drive the Kappa's is finally over. Sadly, the XPA-2 fell short even using it biamped, it sounded scratchy on the highs, and kept shutting down on the woofers. That doesn't mean it's a bad amp, far from it. Like another in this thread said, that not what it's designed for, plain and simple. I had a Carver TFM 55x driving them. This amp is amazing. It drove them very well, with almost no problem. Sadly, the Kappa's are a bit much even for this powerhouse... by itself. It would do well all the way up to 0.0 or even higher on the xsp-1 volume knob, but only if the speaker xovers were set on normal, rather than extended. So I figured, if one is good, two should be great! Well, I am here to tell you that this is the case. I just got my second 55x in, biamped, set the crossovers to extended, and promptly went up to +2 on the xsp-1. No problems! That's what it takes folks. Attachment Deleted |
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Post by Boomzilla on Jun 18, 2015 14:55:35 GMT -5
Congrats, generalkorrd - I'm glad you found a combo that worked for you! Sometimes, you DO have to experiment! Boomzilla |
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Post by generalkorrd on Jun 18, 2015 15:04:38 GMT -5
Plus, NEEDLES!
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