Fried LSi7?

alan850

I think I have really screwed up. Here's the deal. Wife forced divorce of beautifully integrated system. Bridged NAD 55 wpc amps (so in theory 110+ wpc) going into JBL 112's. After 16 years of audio bliss, my wife forced me to get smaller speakers. LSi7's specs say up to 150 wpc, so I bought a pair of LSi7's and moved the JBL's out.

Hooked up the new speakers. My amp manuals talk about "polarity" of speakers and doesn't indicate that getting + and - from amp to speaker is important. In fact, suggests switching + and - if necessary to get best sound.

LSi7 manual says to "be certain" to get + and - correct from amp to speaker.

I didn't pay attention to how + and - were hooked up. Listened to some morning music with the family around at low volume, no problem. Kids off to soccer and I cranked it for the first time (to only 5 on the dial). Good sound for 45 seconds, then both channels started cutting out as my integrated and power amp "protection" features started to kick in and shut down the sound.

Thanks for staying with me this far. Now if I put any volume to speak of to the right speaker, my integrated amp shuts it down. Right speaker has nothing but tweeter and very low volume scratchy woofer. Sounds very bad. I think I had + connected to -. Did I destroy it? Any diagnosis or suggestions for repair? Speakers are dealer "demos" I bought off the web. Thanks in advance.

ben62670

Try swapping channels. LSI's are 4ohm speakers, and when you bridge an amp it can only handle half its ohm rating. If your amp can handle 4 ohms stereo than you shouldn't present a 4 ohm load bridged. take your left amp, and hook it up to your right speaker. Let us know what happens.

Welcome to Club Polk
Ben

danger boy

i think you may have either fried the driver or the crossover in da speaker.

F1nut

Put another way. Bridged amps are not designed to handle less than 8 ohm loads + the Polk's are 4 ohm speakers = bad juju.

alan850

I switched amp hookups and have the same problem with the same speaker. I think it is the speaker. If some component of the speaker is fried, how big a deal is this to fix? Is my only option to send it back to Polk or is this something I can fix. Thanks, again, in advance.

ben62670

Call Polk customer service, and they can help you. They have the best customer support I have ever dealt with. Mention that you are a Club Polk member too.