Hi. Tonight I installed two new Alnico speakers in my '66 Pro Reverb (see the link). http://avatarspeakers.com/home/product/hellatone-sa40/ When I powered the amp up they sounded awesome, just what I was looking for- a raunchy Neil Young grind. At 96db they were much quieter than my previous speakers which is what I wanted, to be able to get old school tube breakup at reasonable volume levels. However, within 5 minutes I could tell that something wasn't quite right. There was a nasty vibration coming through them similar to when the old Utahs blew and the cones began rubbing on the voice coils (from what my amp tech said), but more noticeable and worse sounding. I was able to figure out that it's just coming from one of the speakers, so the other one is good. I was running the amp loud, but the Pro Reverb is a 40-watt amp, and with a switch to a 5U4GB rectifier tube it should only have been putting out about 35 watts, so two 40-watt speakers for a total of 80-watts of power handling should not have a problem with the power of the amp. So there's no way I could have blown the speaker right off the bat. The only thing I could think of was maybe my soldering job wasn't clean enough and the connection isn't as strong as it should be. If that was the case, would it cause it to sound like a blown speaker? If not, are there any other possibilities for why it would sound like that, besides it being a defective speaker? Any advice is appreciated.