Powering Rti a9s

Would Parasound A21 adequately drive Rti a9s?

Answers

  • sponger
    sponger Posts: 325
    edited September 2018
    That amp has gain knobs. You might look up a tutorial on setting gains i.e. level matching. Maybe use a decibel meter phone app to set 3/4 volume at 75 db from the listening position since you'll be looking at 250 w/chann, being as that the RTiA are 8 ohms.
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  • jayu969
    jayu969 Posts: 112
    I know the A9's require lots of good power and the A21 should do well with those.
  • I am wondering myself if I have enough power. I have a crown K1 thats been rebuilt and it sounds good . its tested to do about 400rms @ 8ohms . I have QSC PLX3002 im going to test that is rated 500rms X2@8ohms. id rather have too much than too little
  • tonyb
    tonyb Posts: 32,902
    It's not just about watts, it's about current, and sound quality. Usually, pro amps are a bit on the bright side, and so are the A9's. Combined, it may be too bright for some, but if you like that type of sound, roll with it.
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  • tonyb wrote: »
    It's not just about watts, it's about current, and sound quality. Usually, pro amps are a bit on the bright side, and so are the A9's. Combined, it may be too bright for some, but if you like that type of sound, roll with it.

    its not bright. treble set to zero or less. not all pro amps are the same. not all crown amps are the same. ive had the usual home amps and high end amps too. there are class A/B pro amps and class D or H ....they are not all the same.
  • tonyb
    tonyb Posts: 32,902
    Nope, they are not all the same, that's why I said "usually". Still, pro amps are built for loud, not necessarily quality. A quality "home" amp will get you more 3 dimension sound, some layers to the musical portrait, more air around the notes. Like I said though, if it floats your boat, roll with it.
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  • rooftop59
    rooftop59 Posts: 7,952
    I will say that while I agree with Tony, pro amps are also built to put out the BASS!!! So, if you feel you are lacking bass, I don't know that any other power is going to help you. However, as Tony says that combination would be like ice picks in most of our ears, so the bright, glaring, very forward highs might be obscuring the bass that is there.

    I would highly recommend getting a used parasound HCA-1200 or 1500 or a B&K reference 200.2 or something similar to see how you like it. The bass will have more flesh and texture, and the highs will be smoother and more laid back, which again will make the bass a bit more prominent in the mix...
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  • while I know what you guys are saying , this is not the run of the mill Crown amp. They actually did make high end home system components at one point and then they dropped that in favor of strictly pro amps. with that in mind. I have a K1 thats been updated and rebuilt . its is not that far off from the PSA2 which is 2nd to only the Reference Crown which is nowhere in the same ballpark as a crown pro amp.

    I never said I was lacking in bass. I actually have said opposite being that the A9 are putting down more bass than my monitor 70's series III did even though similar in design. the A9's have more low end

    A B&K amp was referenced, I had 2 or 3 of those . I am not some newbie who never heard a home amp. ive had a few dozen home amps and preamps and a few dozen AVR's and processors.

    ALl in search of 2 channel music. im not out for loud. you can have loud and sound like crap. right now my crown k1 playing Hotel California sounds about as good as my best B&K amp ever did.

    at same time ..I just tested a QSC PLX3002 on my mains and it sounded thin and hollow with no depth and it was a 500rms amp. so I know the Crown I am using sounds better at the very least.
  • tonyb wrote: »
    It's not just about watts, it's about current, and sound quality. Usually, pro amps are a bit on the bright side, and so are the A9's........

    Thats correct! So, on that note:The RTi A9’s listening-window response (a five-point average of axial and +/–15-degree horizontal and vertical responses) measures +0.61/–2.91 decibels from 200 hertz to 10 kilohertz. The –3-dB point is at 49 Hz, and the –6-dB point is at 40 Hz. Impedance reaches a minimum of 4.49 ohms at 67 Hz and a phase angle of –49.39 degrees at 22 Hz.

    The CSi A6’s listening-window response measures +2.17/–2.65 dB from 200 Hz to 10 kHz. An average of axial and +/–15-degree horizontal responses measures +2.06/–3.58 dB from 200 Hz to 10 kHz. The –3-dB point is at 73 Hz, and the –6-dB point is at 63 Hz. Impedance reaches a minimum of 4.63 ohms at 5.3 kHz and a phase angle of –34.92 degrees at 105 Hz.

    The FXi A6’s three-face averaged response in dipole mode measures +1.87/–3.60 dB from 200 Hz to 10 kHz. The –3-dB point is at 75 Hz, and the –6-dB point is at 61 Hz. Impedance reaches a minimum of 4.22 ohms at 9.4 kHz and a phase angle of –36.14 degrees at 108 Hz.
    Read more at https://www.soundandvision.com/content/polk-rti-a9-speaker-system-ht-labs-measures#FBMOiZODXYWECxbB.99

    So, most amplifiers have accounted for drops in resistance, your amp probably doubles the watt output from the extra current given at 4 Ohms resistance from the A9's 8 Ohms nominal resistance. None of the three examples even hit 4 Ohms, so it's all about the watts now. I would think 300 watts or more, IMHO.