• 04-15-2004, 02:04 PM
    polk7c
    Newbie seeks help with resistance issues
    I inherited a Yamaha A-520 amp. on the back it says A or B----6-16 ohm per speaker,
    A AND B---12 ohm min per speaker. Is there a way I can drive either one or both sets of Polk 7C's (4 ohm, but I bought them for a song!), by soldering in resistors, or something?
    I hooked one set up (before I knew that they were 4 ohm, I'm kinda audio illiterate) at loud volume the breakers in the speakers tripped. That's when I began to check things out. The Yammy is 290W 365VA at 60 HZ , I used 10 ft. of 10 gauge booster cable.(hey-I had it).Anything I can do to sustain kinda high volumes?? We want to use these guys in a dance studio, and we need to hear the music over a bunch of little tappers.....We're also pretty much low budget!! please...PLEASE...help!! Thanks!!
  • 04-15-2004, 02:30 PM
    polk7c
    Upon further investigation of this site, I figured out that it's the amp's circuitry that shuts down, not the speakers, but I still want to use these pieces. Any help out there?
  • 04-15-2004, 07:20 PM
    mtrycraft
    Quote:

    Originally Posted by polk7c
    Upon further investigation of this site, I figured out that it's the amp's circuitry that shuts down, not the speakers, but I still want to use these pieces. Any help out there?

    Not with those amps at such a place with high plaback levels. You need an amp that is rated for 4 ohm continuous operation, or different speakers.
    If you are thinking of a resistor, it would need to be huge as half the power will be in it and then you will loose volume in the speaker.
  • 04-16-2004, 08:24 AM
    polk7c
    live and learn
    Thanks for the advice. After wandering around this site for a while, I kinda came to that conclusion. What a shame, because I don't have a lot invested in these pieces. Is anyone familiar with either the Yammy A-520 or the 7c's? I mean, should I junk the amp and keep the speakers, or vice-versa? The tap room is about 1500 sq. ft., wood floor, lots of glass, high ceiling. (former classroom). I realize there is plenty of great tailor made stuff out there, but budget is a major concern..........yard sale season is almost upon us up here in the north, so....... Anyway, thanks for the help, I hope I'm not wasting anyone's time!!
  • 04-16-2004, 08:09 PM
    mtrycraft
    Quote:

    Originally Posted by polk7c
    Thanks for the advice. After wandering around this site for a while, I kinda came to that conclusion. What a shame, because I don't have a lot invested in these pieces. Is anyone familiar with either the Yammy A-520 or the 7c's? I mean, should I junk the amp and keep the speakers, or vice-versa? The tap room is about 1500 sq. ft., wood floor, lots of glass, high ceiling. (former classroom). I realize there is plenty of great tailor made stuff out there, but budget is a major concern..........yard sale season is almost upon us up here in the north, so....... Anyway, thanks for the help, I hope I'm not wasting anyone's time!!


    No, you are not wasting anyones time. They either respond or not :)

    With such a large room, you need good stuff. Either you need a speaker that is very sensitive, close to 100dB spl / 1 watt of power, or a better amp.
  • 05-02-2004, 09:57 PM
    raja10
    Series circuit
    It would be possible to connect the speakers in a series circuit if they are the same models.
    As in Ohm’s law connecting one speaker + to the other speaker – then connecting the + & - that is left to the amp would result in a 8 ohm load. The draw back is the power from the amp would in essence cut in half. This may not give you the volume you are requesting but it would keep the amp from shutting down do to low impedance. Something like you said with resister but you would be using the second set of speakers as the resister. Each of the speakers would receive the same amount of power.
    Not the best way, but it should work OK.
    Ohms law says:
    4ohm + 4ohm paralleled= 2ohms
    4ohm + 4ohm in series= 8ohms