Kappa 9 Bi-Amp strategy...

Discussion in 'Infinity Loudspeakers' started by Speedbump71, Sep 30, 2016.

  1. Speedbump71

    Speedbump71 Klipsch Guy Subscriber

    Messages:
    530
    Location:
    Dandridge, TN
    While I wait for my Millersound polydomes to materialize, I have been pondering my amplification strategy for these Kappa 9's I bought.

    I am going to be using my Parasound 2250 for both speakers, which is capable of 400W into 2Ω. Current capability is 45A per channel.

    I also have a G.A.S. Son of Ampzilla ready to hit my bench, and was wondering if it would handle the big impedance dip at around 7k-11k if I used it to power the top end. I think it will do 320W into 2Ω.

    Anybody have any ideas? I will probably try it regardless, but don't want to spend a bunch of time on the SOA and then just blow it up again.

    Speed
     
  2. savatage1973

    savatage1973 Super Member

    Messages:
    3,708
    Location:
    NW Pennsylvania snow belt
    I own Kappa 9's (one pair now, but had 3 pair at one point). They love the juice. I feed mine with Aragon 4004's and I just got out my Krell KMA 160's--4 of them. There are two impedance dips you have to worry about--the one at 7KHz is nothing--the one at about 33Hz is the one that you have to worry about. Both are below a 1 ohm load, the high one being around 0.9 ohm and the low one is 0.7 ohm--they can eat an amp for lunch.
     
    Last edited: Oct 1, 2016
  3. mwc951

    mwc951 AK Subscriber Subscriber

    Messages:
    180
    2 x Adcom GFA-5800 feed my Kappa 9's.
    These amps are set up such that I can bi-wire them as well.
     
  4. whoaru99

    whoaru99 Epic Member

    Messages:
    36,767
    Location:
    LoTL
    It would be interesting to try something like a pair of Crown Micro or Macro Techs with them, even running full range.

    I bought a pair of Crown Micro Tech 1200s to run in parallel-mono mode with some Thiel CS3.6. But, with impedance dropping to just 2.5-2.7 ohms, they really didn't challenge the amps enough to make parallel-mono much of an improvement.

    In parallel-mono mode the Crowns are rated for 1 ohm operation, with 1,300W of output per amp @ 1 ohm.
     
  5. Superampman

    Superampman AK Member Subscriber

    Messages:
    2,618
    Location:
    Kitchener, ON.
    So have you been brave? If you're still interested, I have no problem driving my K9s with not only my SoA but Grandson as well. These amps are built for this. Contrary to what you may find in some threads here, the sensitivity of the K9s is in fact according to published spec. They are all of 100db. Just don't overdrive your fully capable amp. The tap gets turned off forthwith. The Ampzillas will melt down, not just blow. So you have a margin of time. Highest volume is when my infrared therm. reads 150deg.F. on the sinks. I then turn it down a bit. About 103db peaks at 13ft.. Not bad for an 80wpch little beast.
     
    Last edited: Dec 9, 2016
    Bahamayellow likes this.
  6. MiamiBoy

    MiamiBoy Active Member

    Messages:
    379
    Location:
    NSB, FL
    My K9 amping strategy that works for me:
    1. Always divide and concur by bi-amping.
    2. Put the higher fidelity / higher cost amp on the top. Don't worry about the high end impedance dip.
    3. Never put an amp you care about on the bottom unless it is one you know is designed to handle the high current load of the low impedance dip.
    4. You don't need a hi fidelity amp to drive woofers. Use a lower cost, high watt "class D" amp on the bottom. I use a Crown 2500 XLS that costs <$500 new and has a built in active crossover. I have to turn its gain down to 3/4 or it generates too much bass from my K9's.
     
    7.62 likes this.
  7. 7.62

    7.62 Gearhead Subscriber

    Messages:
    500
    Location:
    Las Vegas
    Not trying to thread jack but just wanted to ask, MiamiBoy, I'm thinking of doing this with the QLS-1's. Only with a bit less using a Crown xls 1502 on the bottom. How is the fan noise at lower levels?

    I had used a GX5 with my Kappa 8's but installed my own switch "voiding the warranty" to control the fan. I'd like not to do that this time. They are different amps but I'm figuring the fans are close to the same.
     
  8. 10ear

    10ear AK Subscriber Subscriber

    Messages:
    268
    Location:
    Kings Mtn, NC
    Have my K 9's with pair of Luxman 3045's on high/mids, a AVA 600R on bottoms. Best sound I have ever had in my room and I have suffered from this affliction since I was a 15 year old. Now 77 plus, had many mid fi, semi hifi set ups as finances allow, but this it for me...... so far!!!!

    Ole Tinear
     
  9. Bahamayellow

    Bahamayellow Active Member

    Messages:
    249
    Hello I'm using 2 Carver tfm-25s in a bi amp mode also. I tried using one and they sounded good but with 2 amps it's a totally different animal. These are rated at 225 watts a channel and go down to 4 ohms listed but have heard they can handle 2 ohm loads ive heard but really don't want to test that theory. I have my woofers set on normal mode and it has plenty of bass for me in my small space. Just wondering how u like your 9s and if those amps are handling them well.
     
  10. 10ear

    10ear AK Subscriber Subscriber

    Messages:
    268
    Location:
    Kings Mtn, NC
    I really like the K 9's. They really sing with these amps. Have to watch volume level as have blown speaker protection fuses on AVA 600 by tempting them in beer loaded mental state. Dodged several bullets on that one and won't repeat that experiment as in "how loud will they go"........
     
    Bahamayellow likes this.
  11. MiamiBoy

    MiamiBoy Active Member

    Messages:
    379
    Location:
    NSB, FL
    I have never heard the fan in my Crown xls 2500 and every time I put my hand on it, it is off. I think it only goes on when the amp starts to get hot. I can't imagine the volume you would have to play it to stress it enough for it to get hot enough for the fan to kick in. Maybe in an arena concert as it was intended.

    While I like the Crown XLS amps for pushing bass, they are not very musical and I would not use them in any application except as bass crankers. They do fine for that purpose on the bottom end of the K9's but I have tried to use them full range on other speakers and IMO they are NOT "high fidelity".
     
  12. 7.62

    7.62 Gearhead Subscriber

    Messages:
    500
    Location:
    Las Vegas
    Ok cool Thank you, I didn't know the crown's can control the fan that way. The QSC GX5 I used with the Kappa 8's was always fan on when you powered the unit on. It wasn't bad but still kinda loud at lower listening levels for Tv watching that's why I installed the switch.
     
  13. nyhifihead

    nyhifihead Active Member

    Messages:
    482
    Location:
    long island NY
    my friend has a crown com tech. we wired my dvc 2 ohm 18"s to 1 ohm and the amp sounded great- its the same power output at 4 ohm bridged (1500w) though so I keep it in bridged mode. It's awesome these amps this flexibility, especially since they are usually on woofer duty where these impedence dips occur.
     

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