Dang it. In the middle of viewing a movie I smelled something burning and immediately shut down all components. I was afraid the TV was burning up. Nope. Everything looked and smelled fine with the TV. The burning smell dissipated before I could pinpoint where it was coming from. SO.....I cranked back up and couldn't hear the movie dialogue.

Inspection of the Polk LSiC center revealed no sound coming from the right-hand (higher-frequency?) driver. That's where the burned smell was coming from, too.

So, my question is.......is this unusual? I've had the LSi's for about a month-and-a-half. The only change I've made was replacing my Onkyo receiver (which I was using as a preamp with an Outlaw 7700 amp) with the Outlaw 990 preamp a few days ago. Been working fine until now. Is there any chance that has anything to do with the LSiC driver blowing?

Crutchfield will ship out a replacement, but the tech support guy said they almost never have any problems with the LSiC. (Of course, I also had to have an LSi25 on the same shipment replaced because the first one's sub was non-functional).

Someone on the Polk forum suggested that the problem might be a bad channel on the 990. (Say it ain't so!)

Any thoughts, guys?

(oh.....Cobalt speaker cables and Outlaw interconnects, by the way)

The right-hand and left-hand drivers both get the same signal (the middle driver is the tweeter, which handles the highest frequencies). A burning smell from a driver sounds like a significant failure. Did the left driver still work? If not, I'd suspect a failure in the crossover network, but if it still worked than it was just that one driver that died.

I don't see how it could be a bad channel in the 990 - the 990's only a pre/pro, with the 7700 actually driving the speaker. The person on Polk's forum may have been thinking that the 990 was a receiver with internal amps. To a certain degree, anything is possible, but I don't see how the 990 could be responsible for blowing one of the drivers on a speaker.

Thanks, gonk. That makes me feel a little better......the left-hand driver still works perfectly.

I was also wondering if it could be related to the trigger cable between the 990 and 7700. There's a brief, but rather disturbing "BUZZZZZZZZZZZZ" when I turn the 990 on. I was wondering if that might be related.

Thanks for your help.

As far as I know, all crossovers include a capacitor in the tweeter line, for shaping and to protect it.
Cheaper filters use an electrolytic here, these CAN dry out but short circuits are seldom.
Doesn't sound like your amp is to blame.
My 990 will arrive here on Tuesday so I don't know about your buzz.
Barend (NL)

Okay, this is probably a dumb question, but I'm trying to learn here, so be gentle with me!

The LSiC has a mylar bypass capacitor in the high-end crossover, and uses a cascade tapered array for separate 2400hz and 200hz crossovers for the two drivers. How does that arrangement correspond to DC blocking and possible speaker damage? Might the different driver crossovers be the reason why only one of the drivers would blow?

As a former Polk dealer...I'd say the speaker simply failed. It's a very common thing from Polk.

Well, it looks like I've been barking up the wrong tree. This is obviously a power issue. I hooked up an old Infinity Primus center speaker that I still had. When I turn on the 7700 I get bad noise (which seems to be lasting longer each time now)......and that old familiar burning smell started coming from the center. It's not blown (yet), but now I'm thinking that I've overloaded the AC circuit, and the damage is cumulative every time I power up the preamp/amp.

So (here's my ignorance showing again) do I need some sort of power conditioning......or a dedicated 20-amp circuit? Or something else. Right now I have everything shut down and am afraid that I'll do more damage if I keep powering up.

A dedicated 20 amp circuit isn't needed. I think you may have something wrong with the 7700 or possibly the 990. I wouldn't power it up until you have a chance to call Outlaw tech support.

did you check your speaker cable? it sounds like it may be something like that also. What size speaker cable are you useing? When I first read you complaint I thaught that you melted a speakercable.

I agree with Daryl that you shouldn't need additional power. It still seems unlikely that the 990 could have a defect that would kill speakers and the 7700's apparently been in the system for a while, but it seems appropriate not to rule anything out yet. Speaker cabling is definitely a candidate.