Should I Bi Amp or use a separate amp??

Hey Guys.....so i recently bought a new receiver pioneer vsx934 but it pushes about half the power my old yamaha pushed.....ive never needed an amp but am looking into 1. Now my towers are 8ohm and bookshelfs are 6 ohm in which this reciever pushes twice as much on 6 ohm so all i need ampd is my towers. Can i run the amp to one set of plugs on my Signature S55's and the other set just to my reciever? Trying to figure out exactly what i need to get to make this thing atleast get 150w p front channel. Thanks.

Answers

  • mhardy6647mhardy6647 Posts: 25,337
    edited January 1
    so, let's see... where to start?

    1) 'half the power' = 3 dB less.
    2) 'twice as much on 6 ohm' ? Really? It's not impossible (i.e., if the amplifier is 'downrated' in terms of its power output into an 8 ohm load vs a 6 ohm load) but it's not likely.
    3) 'pushes'? :/


    If you want 'at least 150 watts* p front channel' -- I think you're gonna want a 150 watt per channel amplifier.

    More to the point, I suppose -- what are you trying to achieve and why do you think "150 watts" per channel is what you need to achieve it?

    ____________________
    * Speaking of watts -- do you understand the interrelationship between voltage, current, power, and impedance? If you don't, do a little reading on Ohm's Law.

    sg9ymg4ne3kq.png

    This is really important because it helps explain why, when it comes to transducing electrical watts of power into acoustic watts of power (or dB of sound pressure level, which is a related but not identical quantity of "loudness"), a basic knowledge of Ohm's Law in its permutations (as shown on the 'wheel' above) illustrates that there's no such thing as a free lunch.

    For example 2.83 volts into a nominal 8 ohm load is one watt of electrical power. 2.83 volts into a nominal 4 ohm load is two watts of electrical power. The difference? Twice as much current has to flow through a four-ohm load compared to an eight-ohm load. If a given amplifier cannot deliver the amount of current needed into a low impedance load compared to a higher impedance load, it cannot deliver the expected amount of power into the lower impedance load.



  • mhardy6647mhardy6647 Posts: 25,337
    So, according to Crutchfield, the sensitivity of the S55 speaker is 90 dB SPL @ 1 meter with 2.83 volts of signal input, and the nominal impedance is 8 ohms. The actual impedance varies as a function of the frequency of the signal being amplified and transduced... but "on the average", at least, Polk claims it is an 8 ohm load.

    What does this mean?

    2.83 volts into 8 ohms is 1 watt.
    If you feed a signal at 1 watt of power into one of these speakers and measure the sound pressure level 1 meter from the speaker, the SPL is supposed to be 90 dB. That is pretty darned loud. OSHA permissible exposure limit to 90 dB SPL is 8 hours.
    https://www.etymotic.com/downloads/dl/file/id/47/product/307/noise_exposure_explanation_of_osha_and_niosh_safe_exposure_limits_and_the_importance_of_noise_dosimetry.pdf

    Move to two meters away, and the SPL drops to 87 dB; four meters, 83 dB, etc.

    If you feed 150 watts of signal into the speaker, and measure SPL 1 meter away, it "should" be (nominally) 111.8 dB. This is dangerously loud, with an OSHA permissible exposure limit of less than 15 minutes per day. More than that will, sooner or later, cause irreversible hearing damage.

    As an aside: If you have two speakers (stereo), the SPL will increase by 3 dB, because there are 2 total watts going into the 2 speakers and being transduced into sound. 93 dB 1 meter away.

    So... it's not really all quite this simple (because the signal of music waveforms isn't at all simple, and amplifiers aren't at all perfect, nor are loudspeakers... and the room environment 'counts', too), but these are sort of the stakes in the sand when it comes to power, impedance, and SPL for these speakers.



  • Wow alot of info. Thanks for taking that time....much appreciated!!
  • audioluvraudioluvr Posts: 2,142
    mhardy6647 wrote: »
    so, let's see... where to start?

    1) 'half the power' = 3 dB less.
    2) 'twice as much on 6 ohm' ? Really? It's not impossible (i.e., if the amplifier is 'downrated' in terms of its power output into an 8 ohm load vs a 6 ohm load) but it's not likely.
    3) 'pushes'? :/


    If you want 'at least 150 watts* p front channel' -- I think you're gonna want a 150 watt per channel amplifier.

    More to the point, I suppose -- what are you trying to achieve and why do you think "150 watts" per channel is what you need to achieve it?

    ____________________
    * Speaking of watts -- do you understand the interrelationship between voltage, current, power, and impedance? If you don't, do a little reading on Ohm's Law.

    sg9ymg4ne3kq.png

    This is really important because it helps explain why, when it comes to transducing electrical watts of power into acoustic watts of power (or dB of sound pressure level, which is a related but not identical quantity of "loudness"), a basic knowledge of Ohm's Law in its permutations (as shown on the 'wheel' above) illustrates that there's no such thing as a free lunch.

    For example 2.83 volts into a nominal 8 ohm load is one watt of electrical power. 2.83 volts into a nominal 4 ohm load is two watts of electrical power. The difference? Twice as much current has to flow through a four-ohm load compared to an eight-ohm load. If a given amplifier cannot deliver the amount of current needed into a low impedance load compared to a higher impedance load, it cannot deliver the expected amount of power into the lower impedance load.


    mhardy6647 wrote: »
    So, according to Crutchfield, the sensitivity of the S55 speaker is 90 dB SPL @ 1 meter with 2.83 volts of signal input, and the nominal impedance is 8 ohms. The actual impedance varies as a function of the frequency of the signal being amplified and transduced... but "on the average", at least, Polk claims it is an 8 ohm load.

    What does this mean?

    2.83 volts into 8 ohms is 1 watt.
    If you feed a signal at 1 watt of power into one of these speakers and measure the sound pressure level 1 meter from the speaker, the SPL is supposed to be 90 dB. That is pretty darned loud. OSHA permissible exposure limit to 90 dB SPL is 8 hours.
    https://www.etymotic.com/downloads/dl/file/id/47/product/307/noise_exposure_explanation_of_osha_and_niosh_safe_exposure_limits_and_the_importance_of_noise_dosimetry.pdf

    Move to two meters away, and the SPL drops to 87 dB; four meters, 83 dB, etc.

    If you feed 150 watts of signal into the speaker, and measure SPL 1 meter away, it "should" be (nominally) 111.8 dB. This is dangerously loud, with an OSHA permissible exposure limit of less than 15 minutes per day. More than that will, sooner or later, cause irreversible hearing damage.

    As an aside: If you have two speakers (stereo), the SPL will increase by 3 dB, because there are 2 total watts going into the 2 speakers and being transduced into sound. 93 dB 1 meter away.

    So... it's not really all quite this simple (because the signal of music waveforms isn't at all simple, and amplifiers aren't at all perfect, nor are loudspeakers... and the room environment 'counts', too), but these are sort of the stakes in the sand when it comes to power, impedance, and SPL for these speakers.



    There you go. Clear as mud
    One foot on audio nirvana and the other in the poor house.
  • ken brydsonken brydson Posts: 7,742
    mhardy6647 wrote: »
    So, according to Crutchfield, the sensitivity of the S55 speaker is 90 dB SPL @ 1 meter with 2.83 volts of signal input, and the nominal impedance is 8 ohms. The actual impedance varies as a function of the frequency of the signal being amplified and transduced... but "on the average", at least, Polk claims it is an 8 ohm load.

    What does this mean?

    2.83 volts into 8 ohms is 1 watt.
    If you feed a signal at 1 watt of power into one of these speakers and measure the sound pressure level 1 meter from the speaker, the SPL is supposed to be 90 dB. That is pretty darned loud. OSHA permissible exposure limit to 90 dB SPL is 8 hours.
    https://www.etymotic.com/downloads/dl/file/id/47/product/307/noise_exposure_explanation_of_osha_and_niosh_safe_exposure_limits_and_the_importance_of_noise_dosimetry.pdf

    Move to two meters away, and the SPL drops to 87 dB; four meters, 83 dB, etc.

    If you feed 150 watts of signal into the speaker, and measure SPL 1 meter away, it "should" be (nominally) 111.8 dB. This is dangerously loud, with an OSHA permissible exposure limit of less than 15 minutes per day. More than that will, sooner or later, cause irreversible hearing damage.

    As an aside: If you have two speakers (stereo), the SPL will increase by 3 dB, because there are 2 total watts going into the 2 speakers and being transduced into sound. 93 dB 1 meter away.

    So... it's not really all quite this simple (because the signal of music waveforms isn't at all simple, and amplifiers aren't at all perfect, nor are loudspeakers... and the room environment 'counts', too), but these are sort of the stakes in the sand when it comes to power, impedance, and SPL for these speakers.



    kc0ah6l1gkxe.gif
    HT/Main- Panny 50" G10 Plasma, Pioneer SC-1222k AVR, Panny DMP-BD60 BDP, Polk LS90 mains, CS350LS center, LS/fx side surrounds, LS50 surround backs, SVS 25-31PC+ sub, Harmony One

    Office Rig- Marantz 2252B, Denon 2910, Kenwood KD2070 TT, Polk RTA 12B's/ RTA8t
  • mhardy6647mhardy6647 Posts: 25,337
    I think a lot of expensive hifi products would be far less successful for their manufacturers if more folks knew Ohm's Law.

    B)

  • BlueFoxBlueFox Posts: 13,268
    mhardy6647 wrote: »
    .....if more folks knew Ohm's Law.

    I agree. Ohm’s law is only relevant for DC circuits.
    Bud - Silicon Valley

    Lumin X1
    Sony XA-5400ES SACD
    Pass XP-22 pre, X600.5 amps
    Magico S5 MKII Mcast Rose speakers, SPOD spikes

    Shunyata Triton v3/Typhon QR on preamp, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • mhardy6647mhardy6647 Posts: 25,337
    BlueFox wrote: »
    mhardy6647 wrote: »
    .....if more folks knew Ohm's Law.

    I agree. Ohm’s law is only relevant for DC circuits.

    That is not correct.
    Ohm's law applies to AC as well; resistance is replaced by impedance.
    If 'we' treat impedance as a constant, all of the above is true as written. .. but of course impedance ain't constant, so it ain't (as I said).

    Now, impedance is a complex quantity since it consists of resitance, capacitive reactance and inductive reactance... and that stuff is all really important, too -- and
    part of why Amplifier A and Amplifier B may -- ahem -- push the same number of watts, but not perform identically into the same load.
  • BlueFoxBlueFox Posts: 13,268
    mhardy6647 wrote: »
    BlueFox wrote: »
    mhardy6647 wrote: »
    .....if more folks knew Ohm's Law.

    I agree. Ohm’s law is only relevant for DC circuits.

    That is not correct.
    Ohm's law applies to AC as well; resistance is replaced by impedance.
    If 'we' treat impedance as a constant, all of the above is true as written. .. but of course impedance ain't constant, so it ain't (as I said).

    Now, impedance is a complex quantity since it consists of resitance, capacitive reactance and inductive reactance... and that stuff is all really important, too -- and
    part of why Amplifier A and Amplifier B may -- ahem -- push the same number of watts, but not perform identically into the same load.

    Thanks for proving my point.
    Bud - Silicon Valley

    Lumin X1
    Sony XA-5400ES SACD
    Pass XP-22 pre, X600.5 amps
    Magico S5 MKII Mcast Rose speakers, SPOD spikes

    Shunyata Triton v3/Typhon QR on preamp, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • aprazer402aprazer402 Posts: 1,851


    What's the current, the current, the current, I want the current. ;)
  • mhardy6647mhardy6647 Posts: 25,337
    BlueFox wrote: »
    mhardy6647 wrote: »
    BlueFox wrote: »
    mhardy6647 wrote: »
    .....if more folks knew Ohm's Law.

    I agree. Ohm’s law is only relevant for DC circuits.

    That is not correct.
    Ohm's law applies to AC as well; resistance is replaced by impedance.
    If 'we' treat impedance as a constant, all of the above is true as written. .. but of course impedance ain't constant, so it ain't (as I said).

    Now, impedance is a complex quantity since it consists of resitance, capacitive reactance and inductive reactance... and that stuff is all really important, too -- and
    part of why Amplifier A and Amplifier B may -- ahem -- push the same number of watts, but not perform identically into the same load.

    Thanks for proving my point.

    Any time -- it's still all 100% true, complete and correct, for any given value of "Z". I mean, that's how amplifier designers... design.
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