I have the 1070 since they were first sold and have had a few of the no audio incidents. But a couple of weeks ago I turned on my 1070 and an extremely loud buzz came out of my speakers. Luckily I immediately turned off the power to the reciever and fortuately didn't damage my speakers. What the hell was that?

That's certainly out of the ordinary. I'd tend to suspect interference or a power problem of some sort, but I'd just be taking a shot in the dark. It hasn't recurred, I hope?

Ranger1000:

This is EXACTLY what happended to me that blew my right speaker a few weeks ago. I got another low-grade dose of it again yesterday when I fired up a DVD.

Fortunately, the past two episodes have been at low volume, so no damage done, but it is quite worrisome.

I was experiencing a loud buzz only when I turn on my amp before the 970. It lasted only a second, but sounded like it could damage my speakers so I now turn on my amp after the 970. Still get a jolt to my subs though.

How long does your loud buzz last?

Could your loud buzz be the power supply discharging the last of its stored power in the absence of an input signal? I've used my Panamax to turn my amps on after my processor and to turn them off at the same time as my processor for many years now, so my case may be different - just theorizing a bit...

I have a 1070 and incur the no-audio problem at least 50% of the time when powering up. It sometimes also happens when changing source material.

I also have the popping sound come from my speakers during what I'll call "power-warm-up". I've noticed that this happens when my unit has been turned off for a period and cooled down completely and then turned on cold. The popping noise lasts about 3 seconds and can be very loud and I imagine, damaging to my speakers. It seems to me that the popping noise is the 1070's amp attempting to reproduce a signal when it's not fully "powered-up".

How would I know if my speakers are damaged? What are the telltale signs?

iardon:

In my particular case, the telltale sign was smoke coming from my tweeter followed by no sound! (I'm not BS-ing you). The woofer damage was more subtle, but created a buzzing sound on certain bass frequencies. When I removed the woofer, I also noticed the cone would grate in places on the spider when you pushed on the driver. I think it must have melted part of the voice coil or something.

For less dramatic damage, listen closely to the tweeter(make sure the volume isn't too loud so you don't damage your hearing) and listen for any crackle or frying egg sounds. It's likely any damage caused by the feedback problem will take out the tweeter or midrange (if you have one) first before damaging the woofer. If you do try the push test (feeling for grating) on the woofer, make sure the music and/or power is off -- you don't want to push on a cone during playback. Also just push in on the driver carefully and shallowly, if the voice coil is in good shape, you should feel a smooth excursion on the driver as it moves back and forth.

Wow, haven't noticed smoke but I do hear what I would call noise (distortion) coming from my tweeters. I know that M&K are known for being accurate but I do wonder if the 970 with its popping/buzzing... you name it, may have damaged my tweeters.

Is it something you've only noticed recently? If you've only just started hearing things that are obviously amusical or laden with distortion since the buzz hit you, you may have a problem.

I would try several different sources with CDs / demos you're very familiar with just to rule out any normal audible hiss, noisy capacitors from older electronics, etc. Bear in mind, with your ear right against the speaker, the 970 and/or your electronics may generate a faint hiss at idle.

Also, when the buzz hit your speakers, how loud was it?

What smoked my tweeter was when the feedback hit during a test tone sweep in speaker calibration mode. This caused the buzz to be startingly loud and thus powerful enough to damage the voice coils.