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Discussion Starter · #1 ·
I'm having a problem I hope someone can help diagnose with me. First the equipment involved:


I have two Lepai 2020A+ 2x20W mini amp units. They are powered by new 12V 5A power supplies. One is hooked up to OSD RS670JR Outdoor Fake-Rock speakers, the other is powering Kicker KB6000 Outdoor speakers. Both pairs of speakers are listed as 8Ohm, having 90dB sensitivity, and power handling of 75W RMS/150W peak. The source is an mp3 player with a line out split to send signal to both units simultaneously.


The problem is, while testing the equipment for the first time, the amp connected to the rock speakers I could turn up almost all the way until the volume is deafening. The other unit with the KB6000s only gets to about 70% and then a click, and no sound until I turn the volume back down. I swapped the speakers at the back of the amps, and the same thing happens. Whichever unit is connected to the KB6000s cuts out, while the unit connected to the rock speakers can turn up all the way.


When I swapped the speakers I left everything else the same, including the inputs and the power supplies, just just disconnected the speaker wires from the units and swapped them. Sounds like the protection circuit kicking in, but why can I turn up the other speakers (which are similarly rated) all the way up? Are my amps telling me my speakers are bad, or is this supposed to happen? Could I have a short somewhere, and if so, how can I check?


I hope I am explaining myself clearly and have given enough information. Also I didn't know if this belonged in the speaker forum or this one. I've learned a lot from this site, but it's my first post, so please let me know if I put it in the wrong forum. Thanks so much!
 

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Discussion Starter · #2 ·
Update to some testing I did, hopefully someone can make sense of this...


I hooked both pairs of speakers from the OP to a multimeter. The rock speakers which I can turn all the way up read about 6 Ohms DC. The KB6000s that cut out at 70% read about 7.1 Ohms DC. I would've expected the opposite, since the rock speakers should be drawing slightly more current based on those measurements.


I also tested one KB6000 speaker at a time, in case one driver had a short. But each speaker individually cut off at the same point, about 70%. I also turned down the base tone control, which allowed me to turn the volume up a little more, but it still cut out around 75%.


Finally, I turned the source signal down (decreased volume on the MP3 player from 10 to 1). With the source at 1, I could turn the amp up to full (not surprisingly). I then turned the source up until it cut out, which happened when the source hit 7, with the amp still at 10.


All this seems to be pointing at the little amp having to drive these speakers too hard, but I don't understand why it can handle the other pair, with almost exactly the same specs. Can anyone help, please!?
 

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Discussion Starter · #4 ·
I'm chalking it up to a bad pair of speakers, or a lying manufacturer. I wasn't willing to risk another shipping charge by ordering another pair of Kicker KB6000s, so I went to two local stores and picked up two different pairs with similar specifications. Both new pairs were able to be driven to the max of my little Lepai, and both were painfully loud at that max level. So I put the volume to a reasonable level and I kept the pair that sounded best. Oh, and I returned the Kickers too.


So is Kicker incredibly overestimating their sensitivity, or was that pair just bad for some reason? I'm inclined to think it was just a bad pair, but the world may never know...


Thanks for asking!
 
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