Daveys Posted October 8, 2009 Share Posted October 8, 2009 Hello to you all, For about 1 year I'm playing with the Klipsch THX Ultra2 set. A month ago I made the descission to buy an extra KW-120 to get some more punch. Now my questions to you guys is, do I need a Crown XTI-2000 or a XTI 4000 to drive them both? The 2000 gives 475W stereo at 8ohms and the 4000 gives 650W at 8ohms. I don't mind paying for some overpower with the 4.000 but it must add something extra compared to the 2000. I hope you guys want to give a honest answer. Dave Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted October 8, 2009 Share Posted October 8, 2009 I won't lie to you, I am gonna lie to you. Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 8, 2009 Author Share Posted October 8, 2009 [] Lie a little [] What I ment was that there are a lot of fairytales about these kind of questions and in the end ending up whit a XTI 6000. What would you recomend? Quote Link to comment Share on other sites More sharing options...
Bill H. Posted October 8, 2009 Share Posted October 8, 2009 If your comfortable with your present setup.......stay there. I don't think you would achieve much more value vs the cost outlay for another Amp......... JMHO. Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 8, 2009 Author Share Posted October 8, 2009 The setup that I have is 3 X KL650 as fronts and center. The center is not hooked up yet and the left and right front are powered by a XTI 1000. For the rear I have 2 X KS525 that are also powered by a XTI 1000 and I have 1 KW-120 which is power by 1 bridged XTI 1000. Later this XTI will power the center with 1 channel. Because I bought a second sub I have to get another XTI to power both KW-120's. I am one channel short at this moment. The KA-1000 is rated at 500W at 8ohms so normally a XTI2000 with 475W at 8ohms should be sufficient. But maybe a 4000 will give something extra. That's something I don't know [:$] Quote Link to comment Share on other sites More sharing options...
J.4knee Posted October 8, 2009 Share Posted October 8, 2009 You should be able to do fine with just a single KA-1000 Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 8, 2009 Author Share Posted October 8, 2009 I got some great help in my PM box [H]. To be short about it, a XTI 2000 should be sufficient. A single KW-120 is 8ohms, two of these subs parallel will make them 4ohms. When you take the KA-1000 at 4ohms it deliveres 1000W. The XTI 2000 at 8ohms deliveres 800W per channel (stereo) so that should be more than enough. Thanks guys for all your help [Y] Dave Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 11, 2009 Author Share Posted October 11, 2009 Some guys do recomend a XTI 4000 on the AVS for the 2 KW-120's. You can't have enough power is the most mentioned remark [:^)] Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 25, 2009 Author Share Posted October 25, 2009 Two quotes from the Crown forum which confuse me a bit to make a wise decision. 1.what is the actual impedance of each speaker (most standard dj and home stereo speakers are 8ohm)? If they are actually 8 ohm speakers, you'll find HUGE gains by bridging them. If you don't know how to do this, study up and ask questions because doing it wrong will break things... expensive things. Anyways, I've found that the XTi's really appreciate one 4 ohm bridged load over two 8 ohm loads (one on each channel as you described). The really low end response (under 60Hz) is nearly non-existent on my XTi4000 at 8 ohms, but has plenty of oomph to make a pair of custom made 18's rattle when bridged down to a 4ohm load. If they are indeed each 4ohm speakers, then disregard this idea as the XTi cannot be loaded to 2ohms when bridged without breaking things... expensive things The reply; 2.The spec of the sub (rated 8 ohms) is specific use only the amp supplied with sub that is rated 1000 watts 4 ohms (so about 500 watts @ 8ohms), so providing 1000 watts per sub with a XTI 2K bridged will probably not help, OP will probably experience failure of sub if not careful. You are saying your amps does not respond below 60 hz at 8 ohms and will work at 4 ohms, i suspect your speaker has a spike in Impedance around 60 hz region and more power at bridged will just compensate for this problem and make you think the amp perform better, because an amplifier should not perform better in freq. response at lower impedance, but will do the same with more power only. My reply; I'm now using 1 XTI 1000 to drive both subs and that gives them 275W per sub or am I calculate wrong? A XTI 2000 with 457W at 8ohm stereo is just under the recommended 500W. I'm a little confused what would be the best decision? [*]2 XTI 1000's is not an option because of the 1000W at 8ohm Bridge-Mono. Stereo will give both subs only 275W at 8ohm so that's not enough? [*]1 XTI 2000 is most near to the Klipsch recommended power (475W vs 500W) but will it be ok because the XTI will always have to work at his best? [*]1 XTI 4000 will be too much with his 650W at 8ohm Stereo. Setting the limiter at 75% will not ask for the most of the 4000 and might be the best option? Quote Link to comment Share on other sites More sharing options...
DrWho Posted October 25, 2009 Share Posted October 25, 2009 One thing about the KA-1000 is that it has built-in EQ and processing specifically for the KW-120 subs. To get the optimum performance out of the KW-120, you would need to emulate that EQ inside your XTi. I am fairly confident the Ultra2 Subwoofer setup (KA-1000 plus KW-120) is taking advantage of the decreased excursion at the tuning frequency and adding lots of boost to a response that is otherwise rolling off early. As far as which amp to get, I would highly recommend the KA-1000. [] If you're dead set on the Crown route, then I would go with the XTi 4000 and run it bridged mono. If I got my facts straight, I believe the power supply in the Xti 4000 is different from the Xti 1000 and Xti 2000 and is going to better handle the lower crest factor and lower frequencies of movie sound effects. The rated power of the 2000 is high enough to drive two subs to their max, but whether or not it can deliver the rated power for a long period of time is what matters more. If you buy too little power, then your max output will be limited by the amplifier. If you buy too much power, then your max output will be limited by the speaker. As long as you don't overdrive either (which you shouldn't do anyway because it will sound horrible), then nothing should blow up. The most important thing is that you get the filtering dialed in properly on the XTi. Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 26, 2009 Author Share Posted October 26, 2009 Hi Mike, Thanks for your reply. I'm struggling now to make the decision to go for the Crown (because all the other speakers are powered by Crown) or the KA-1000. The advantage I see with the Crown is with a future change in set up I can still use it. The down side is that I will have to put in a lot of efford and time to get everything right and I will probably have to get an external crossover. The advantage with the KA-1000 is that everything is matched by Klipsch. The crossover is already there and it's almost plug and play. As mentioned above the downside is that I can only use it in combination with the KW-120's. What I'm just thinking is when I would like to sell it will be more valuable with the KA-1000. Hmm, I think I answered my question myself [:S]. Thanks again Mike! Dave Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 27, 2009 Author Share Posted October 27, 2009 You should be able to do fine with just a single KA-1000 In the end I folowed your advice []. I just ordered a Klipsch KA-1000-THX amplifier for the two subs. I got to much different answers on several forums. Besides that the Klipsch had the big advantage to have possibilities of finetuning the subs (boundary gain compensation, lowpass crossover, phase, etc). Dave Quote Link to comment Share on other sites More sharing options...
Daveys Posted October 27, 2009 Author Share Posted October 27, 2009 One thing about the KA-1000 is that it has built-in EQ and processing specifically for the KW-120 subs. To get the optimum performance out of the KW-120, you would need to emulate that EQ inside your XTi. I am fairly confident the Ultra2 Subwoofer setup (KA-1000 plus KW-120) is taking advantage of the decreased excursion at the tuning frequency and adding lots of boost to a response that is otherwise rolling off early. As far as which amp to get, I would highly recommend the KA-1000. You made me think and got me to my current decision. Thanks for that [Y]. I know have the complete 7.2 THX Ultra2 set and I'm very happy with it. I only use 5.2 at the moment because I can't place all speakers in the current situation. When the garage is rebuild it will be a home theater room and the 7.2 will not be a problem [H]. Dave Quote Link to comment Share on other sites More sharing options...
mrogge Posted December 5, 2009 Share Posted December 5, 2009 Hi. I am about the purchase amps for my THX Untra II system. I had my eye on the same processor, amps, etc. Im wondering if you regret your decision to use the Klipsch amp for the subs? I havent opened the box yet. Quote Link to comment Share on other sites More sharing options...
mrogge Posted December 5, 2009 Share Posted December 5, 2009 Also.. what do you think about bi-amping the speakers with those crown amps? (7 crown amps instead of 4) Quote Link to comment Share on other sites More sharing options...
Daveys Posted December 5, 2009 Author Share Posted December 5, 2009 I don't regret anything and I would buy the KA-1000 in a second. It's an absolute no brainer. You will have everything you need to get the subs blend in with your other speakers. Regarding the other speakers in combination with the Crown's I can't tell you anything about the bi-amping. I haven't tried it and I'm not going to. It already gives so much power and I'm fine with it. Quote Link to comment Share on other sites More sharing options...
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