What is the best way to power my new LSI9's with my current equipment?

packetjones
packetjones Posts: 1,059
edited February 2012 in Speakers
So i recently picked up some new gear from some fellow polkies and was curious what would be the recommended way to power them. I picked up a Rotel RB956ax and some LSI9's. i also have a HK254 AVR as well. What does everyone think would be the better way to power these? I can bridge the rotel into 3 channels at 90w each. The Rotel does not have a 4ohm rating as far as I can tell and the HK surely doesn't.

#1 - Connect to the Harman Kardon AVR @ 65w/ch 8ohms
#2 - Connect to the Rotel in bridged mode @90w/ch
#3 - Connect to the Rotel in non bridged mode @ 30w/ch (using jumpers)
#4 - Connect to the Rotel in non bridged mode with 30w to each set of binding posts (no jumpers)

I am thinking that #2 or #4 would be best but I am not sure. Opinions?
Front - RTiA5's
Rear - RTiA3's
Center - CSiA4
Sub - PSW110
Post edited by packetjones on

Comments

  • nhhiep
    nhhiep Posts: 877
    edited February 2012
    For Lsi9, you need all the power you can get. I'd say bridge the rotel for Lsi9s, then your AVR powers the rest. Or just plug the Lsi9s straight to the wall outlet :)
  • steveinaz
    steveinaz Posts: 19,538
    edited February 2012
    Don't run bridged, especially with a 4ohm speaker. Niether is a good option, but for the time being I would keep playback at lower levels to keep from clipping the amp(s). I would do number #3 and not push the speakers hard.

    Bridging essentially halves speaker impedance, meaning a 4ohm speaker would have a 2 ohm appearance to the amp----NOT GOOD.

    You need more power, and an amp with 4 ohm load capability (high current).
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • rooftop59
    rooftop59 Posts: 8,121
    edited February 2012
    Patrick I am sure that others with more knowledge will chime in, but I think that as a general rule you do not want to run a bridged amp into a 4 ohm load, others can explain why better than me. So since the 9s are bi-ampable my suggestion would be #4. That way you are essentially getting the same power as #2 to your speakers, but without straining the amp in the same way.

    sounds like a sweet combo. Hope you enjoy it!
    Paul
    Living Room 2.2: Usher BE-718 "tiny dancers"; Dual DIY Dayton audio RSS210HF-4 Subs with Dayton SPA-250 amps; Arcam SA30; Musical Fidelity A308; Sony UBP-x1000es
    Game Room 5.1.4:
    Denon AVR-X4200w; Sony UBP-x700; Definitive Technology Power Monitor 900 mains, CLR-3000 center, StudioMonitor 350 surrounds, ProMonitor 800 atmos x4; Sub - Monoprice Monolith 15in THX Ultra

    Bedroom 2.1
    Harmon Kardon HK3490; Bluesounds Node N130; Polk RT25i; ACI Titan Subwoofer
  • tonyb
    tonyb Posts: 33,011
    edited February 2012
    Ditto what Steve said. That Rotel is pretty weak for the 9's, keep the volume down until you can feed them some good power, and don't bridge. We have plenty of threads on powering LSI's, look some up.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • packetjones
    packetjones Posts: 1,059
    edited February 2012
    I picked up the rotel to be bridged and run my A5's and center in the HT. This would be almost twice as powerful as the HK alone for the front stage. I am now looking to get a nice little 2 channel system going and was going to re-purpose the Rotel until I get a different amp. I know i need to get a better amp in the long term but want to listen to the 9's now. lol
    Front - RTiA5's
    Rear - RTiA3's
    Center - CSiA4
    Sub - PSW110
  • Drenis
    Drenis Posts: 2,871
    edited February 2012
    nhhiep wrote: »
    For Lsi9, you need all the power you can get. I'd say bridge the rotel for Lsi9s, then your AVR powers the rest. Or just plug the Lsi9s straight to the wall outlet :)

    Are you trolling? Wow...:rolleyes: You didn't even offer the guy any solid advice.

    OP - Look for a stable 4-ohm amplifier that's reputable and is well reviewed. Even a basic 100 wpc @ 4 ohm from a good amplifier will be better then your basic options and won't break the bank.

    Do you have pre-outs?
  • steveinaz
    steveinaz Posts: 19,538
    edited February 2012
    The BIG thing is to go easy with the volume until you can get some higher current, 4ohm capable amp.

    Perspective; I had a pair of Lsi9's that Wes brought down. We were powering them with my 215watt/8 ohm; 385watt/4 ohm Parasound. The 9's had no problem gobbling up that amplifier power. Keep in mind, my amp is 60amp/channel current capable. We only noticed the 9's running out of steam (beginning to compress) at crazy concert levels, in a 18 x 36ft room!

    Moral of the story, you need lots of high current capable power to ensure you wont clip the output to the Lsi9. See the impedance chart below for the Lsi9....NOTE: the 2 ohm dip at 50hz!
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • packetjones
    packetjones Posts: 1,059
    edited February 2012
    Drenis wrote: »
    OP - Look for a stable 4-ohm amplifier that's reputable and is well reviewed. Even a basic 100 wpc @ 4 ohm from a good amplifier will be better then your basic options and won't break the bank.

    Do you have pre-outs?

    i do have pre-outs on the HK. Long term I plan on leaving the HK in the HT and setup a separate 2 channel system. i would also get a different amp in the future. In fact i am scanning the web now for one. A nice dedicated 2 channel amp is in the future for sure but may be a little while before i can pick one up.

    What exactly is an integrated? Is it just a pre/pro in a single box, typically lower power than a stand alone pre/pro? Could I use this and then add a separate amp later?

    Thanks for all the feedback.
    Front - RTiA5's
    Rear - RTiA3's
    Center - CSiA4
    Sub - PSW110
  • steveinaz
    steveinaz Posts: 19,538
    edited February 2012
    An integrated amp has the preamp/amp sections in one chasis. Some integrateds have pre-outs, some don't. A pre-out would allow connection of a bigger amp later down the road; thereby by-passing the internal amplifier section.

    A good integrated amp is a cost-effective way to get into higher-end sound/more power for relatively less money than all out seperate components. The key is to make sure it's got a 4 ohm specification for power output.

    Think of current flow like a water hose. You connect a typical garden hose to your household supply, no problem---the hose can flow enough water to keep up with the demand. The hose and the residential water flow pressure are designed to work together. Now connect that garden variety hose to a fire truck.....POP goes the weasel. This is synonymous to driving a 4 ohm speaker with an amp that can't "flow" enough current to keep up---so the amp overheats, hopefully not destroying your speakers in the process. Remember, less impedance = more current flow; the question is, can your amp flow that much current safely?
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • F1nut
    F1nut Posts: 50,754
    edited February 2012
    And some integrated amps are two chassis.

    packetjones, #4 is your only real option at this time.
    Political Correctness'.........defined

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    President of Club Polk

  • pyrocyborg
    pyrocyborg Posts: 524
    edited February 2012
    As f1 said. Do not bridge, as it would most probably kill your amp. Listen to your LSi9 at low to moderate volume, and get a quality 4 ohm amp. You don't really need 150w to make them sound great, but if you're in a big room or like loud music, they'll need it. Otherwise, you can do great with a quality 75-100w 4 ohm amplifier.

    For example, I wouldn't call my NAD326 high-end by any mean, but it does drive my LSi7 quite easily, in fact without breaking a sweat. Sure, they are way easier to drive than a pair of LSi9, but at normal listening level (under 80 dB), they do not even require most than a few watts... even if you consider than LSi9 requires you to double that amount of power, it should not require anything more than a 10w amp if you listen at around 85 dB in a small to medium-sized room (200ish square feet)... but there again, it would give you little to no room if you crank it up a little. To drive them at concert hall level, sure, you'll need something like a 250-300wpc 4 ohm capable amp.
    Speakers: Polk Audio LSiM 705, LSiM 703, LSiM 704c
    Receiver: Denon X3500H
  • packetjones
    packetjones Posts: 1,059
    edited February 2012
    Any reason why I should not get something like this Adcom Amp for $200? It seems like it would work great.
    Front - RTiA5's
    Rear - RTiA3's
    Center - CSiA4
    Sub - PSW110
  • steveinaz
    steveinaz Posts: 19,538
    edited February 2012
    Looks good, strong 4ohm specifications for power.
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • packetjones
    packetjones Posts: 1,059
    edited February 2012
    Also would i just need to get a slitter to split the pre-out from the receiver into 2 channels on the amp? I am looking to use solution #4 from my original post.
    Front - RTiA5's
    Rear - RTiA3's
    Center - CSiA4
    Sub - PSW110
  • PSOVLSK
    PSOVLSK Posts: 5,224
    edited February 2012
    I've run LSi's with that Adcom with good results...with an H/K as my pre-.

    Just hook up the pre-out of the AVR to the input of the amp via a decent IC. You'll need two IC's, L/R.
    Things work out best for those who make the best of the way things work out.-John Wooden
  • tonyb
    tonyb Posts: 33,011
    edited February 2012
    Also would i just need to get a slitter to split the pre-out from the receiver into 2 channels on the amp? I am looking to use solution #4 from my original post.

    Yep, that would work.
    HT SYSTEM-
    Sony 850c 4k
    Pioneer elite vhx 21
    Sony 4k BRP
    SVS SB-2000
    Polk Sig. 20's
    Polk FX500 surrounds

    Cables-
    Acoustic zen Satori speaker cables
    Acoustic zen Matrix 2 IC's
    Wireworld eclipse 7 ic's
    Audio metallurgy ga-o digital cable

    Kitchen

    Sonos zp90
    Grant Fidelity tube dac
    B&k 1420
    lsi 9's
  • pyrocyborg
    pyrocyborg Posts: 524
    edited February 2012
    Get yourself a pair of Blue Jeans Cable interconnect, or Signal Cable ones. They are durable and sturdy cables at low prices (but not cheap low prices like monoprice... but monoprice interconnects has "tight" connectors, which can break your inputs after a lot of removals).

    Considering you're on a budget, I wouldn't look elsewhere except for used stuff, and there again, those two prices offer a great price/performance ratio.

    Then, you'll have enough power to drive those babies.
    Speakers: Polk Audio LSiM 705, LSiM 703, LSiM 704c
    Receiver: Denon X3500H