Power amps — Their ohms rating

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mee6
mee6 Posts: 13
in Electronics
Hi there,

I just got into reading about Ohms and how they relate to power amps.
However I'm still a bit confused about what to look for in an amp.

My impression is that 2 x RTI A9 will have a total impedance/load of 4 ohms.
2x RTI A9 and the CSIA6 will have total load of 2.67 Ohms.

Looking at the Parasound A 31 it can do 400 watts at a 4 ohms rating.

My impression is that if I get an A31, connect 2x A9 & a CSIA6, it will only do a maximum of 400 watts to each channel even though the total impedance is lower than 4.
Are my assumptions correct?

Thanks,
  1. Speakers
  2. center — CSi A6
  3. fronts — 2 x RTi A9
  4. rears — 2 x RTi A3
  5. Ceiling — 2x RC 80i
  6. Subwoofer — SVS PB-3000
  • Amplifiers
  • Anthem A5
  • Anthem A2
  • Marantz AV-7704
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  • F1nut
    F1nut Posts: 49,795
    edited April 2018
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    Each of those speakers is an 8 ohm nominal load. Therefore, each amp channel will see an 8 ohm nominal load.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • [Deleted User]
    [Deleted User] Posts: 7,658
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    Hello,
    Usually most of our audio systems have one speaker connected to one amplifier channel. If we have a two speaker system each speaker will be separately connected to an amplifier channel. The same for a three or five speaker system, each speaker connected to an individual amplifier channel. It is rare that two speakers will be connected to a single amplifier, let alone three.
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  • mee6
    mee6 Posts: 13
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    Thanks F1nut & Kenneth.
    I see my mistake now, your explanations make more sense.

    So is my goal to match a power amplifiers watts per channel for its impedance to the speakers power capability?


    Let me know if i'm still in left field.
    1. Speakers
    2. center — CSi A6
    3. fronts — 2 x RTi A9
    4. rears — 2 x RTi A3
    5. Ceiling — 2x RC 80i
    6. Subwoofer — SVS PB-3000
    • Amplifiers
    • Anthem A5
    • Anthem A2
    • Marantz AV-7704
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  • F1nut
    F1nut Posts: 49,795
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    Not really. You can drive a speaker rated to handle 200 watts with a 1000 wpc amp without issue 99% of the time.

    On the other hand using a 20 wpc amp to drive a speaker with a suggested minimum power rating of 50 watts will not result in the best performance. In fact, you are more likely to damage the speaker with an underpowered amp.

    Audio fact, all watts are not created equal.

    The current (amperes) rating of an amp is more important than the wpc. That spec isn't always presented, but a general rule of thumb is if the wpc rating doubles from 8 ohms to 4 ohms it's a high current amp.

    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."

    President of Club Polk

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  • [Deleted User]
    [Deleted User] Posts: 7,658
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    I believe that Parasound is a great match for Polk speakers, many satisfied owners.
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  • Joey_V
    Joey_V Posts: 8,519
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    I believe parasound is good, period
    Magico, JL, Emm, ARC Ref 10 line, ARC Ref 10 phono, VPI, Lyra, Boulder, AQ Wel, SRA Scuttle Rack, Bluesound
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  • Clipdat
    Clipdat Posts: 12,599
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    Personally I wouldn't buy anything below their "JC" designated stuff.
    Joey_V wrote: »
    I believe parasound is good, period

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  • tonyb
    tonyb Posts: 32,906
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    Clipdat wrote: »
    Personally I wouldn't buy anything below their "JC" designated stuff.
    Joey_V wrote: »
    I believe parasound is good, period

    Well then you'd be missing out on some great products below that JC designation.
    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
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  • dolbyd
    dolbyd Posts: 430
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    tonyb wrote: »
    Clipdat wrote: »
    Personally I wouldn't buy anything below their "JC" designated stuff.
    Joey_V wrote: »
    I believe parasound is good, period

    Well then you'd be missing out on some great products below that JC designation.

    Clipdat
    I agree with Tony they are a great brand.
    That being said have you checked out the new JC5. Very nice.

    http://www.parasound.com/jc5.php
    Main room- RTiA9 x4, CSiA6, in ceiling Atmos RT-70 x4, SVS PC 4000 x2, Marantz 8805A, OPPO 203, Emotiva DR3 G3, Emotiva XPA-2 G3, Emotiva XPA-5 G3, Emotiva X300, Sony 75" 940E, Panasonic Plasma VT50, PS Audio Power Port X2, PS Audio AC-5 x8, AQ Rocket 33 Biwire speaker cables, AQ King Cobra XLR IC, Furman PFi20 W/Cullen cable, SoildSteel S4-4 rack, Gik room treatments

    Office- Legend L600, in ceiling Polk RC80i, Marantz 7704, OPPO 203, Pioneer Elite PDF-59 CD, PSA Stellar 300, Sony 55" 800B, Gik room treatment

    Master BR- Signature ES60, Signature S35 Center, Signature S15 Dolby Height, LSI700 in ceiling, SVS-SB4000, Marantz 5012, Emotiva XPA5 G2, OPPO 203, Pioneer DVL-919 Laser Disc, Sony 55" OLED

    Patio- SDI Atrium8 x3, Emotiva A-100 amps x3
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  • pitdogg2
    pitdogg2 Posts: 24,560
    edited April 2018
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    Clipdat wrote: »
    Personally I wouldn't buy anything below their "JC" designated stuff.
    Joey_V wrote: »
    I believe parasound is good, period

    Coming from a guy who bought a $99 dac....
    :(:(:(
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  • Clipdat
    Clipdat Posts: 12,599
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    It was actually $89.99
    pitdogg2 wrote: »
    Coming from a guy who bought a $99 dac....
    :(:(:(

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  • pitdogg2
    pitdogg2 Posts: 24,560
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    I rest my case ;)
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  • mee6
    mee6 Posts: 13
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    Hey guys,
    Thanks for all the input.

    However seems that it got off topic a bit.
    Last thing we need is our friend ravaneli saying Emovita is better than any of your suggestions.

    I'd like to start a new thread around this idea:
    F1nut wrote: »
    Audio fact, all watts are not created equal.

    The current (amperes) rating of an amp is more important than the wpc. That spec isn't always presented, but a general rule of thumb is if the wpc rating doubles from 8 ohms to 4 ohms it's a high current amp.

    And another in terms of comparing 2 amps I have been eyeing.
    1. Speakers
    2. center — CSi A6
    3. fronts — 2 x RTi A9
    4. rears — 2 x RTi A3
    5. Ceiling — 2x RC 80i
    6. Subwoofer — SVS PB-3000
    • Amplifiers
    • Anthem A5
    • Anthem A2
    • Marantz AV-7704
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