[kingdeezie]

So, Danny, or anyone else who might be able to answer my question...

I have a pair of LS-6s from AV123....

Last week I decided to test how loud these things can go...

I chose a track that started off relatively quiet, with just a piano playing at first.

I turned my Mapletree Audio Design preamp a little bit past half way. The MAD was feeding its signal to a pair of Stratos Mono Extreme SE Pluses...

I noticed that after a certain point on the preamp, the BG Neo's started to crack. Obviously since it was immediately apparent that something was wrong, I panicked and quickly turned it down, in which case the problem was immediately resolved.

I haven't had any distortion or problems since that point, but I am trying to figure out what actually happened, and if there is something wrong with my LS-6es.

I don't have a real DB meter; I was using the JOKE DB meter on the iphone for some reference. It can't read peaks over 105 DBS, but it gives "Averages," and it was reading anywhere from 96 DBs-100 DBS.

Basically, I have boiled it down to several scenarios...

1) One or several of my BG Neos is blown. I tend to rule this out though since it only becomes an issue after a certain point on the preamps volume.

2) I am clipping my Stratos Mono Extreme SE's. I think these are rated at 200+ watts per block, but they do pass a BOAT load of current.

3) I was reaching the mechanical limit of the Neos. Reading the specifications though, it would seem that they can take 50 watts a piece. So perhaps unlikely.

So, does anyone have any idea of what it could possibly be.

I would rather it be that I am hitting the limits of my amp, since I can always one day get something with more juice. To think that I have hit the limit of the speaker is a little upsetting.

[S Clark]

Definitely something sounds off.  The LS6's and 9's are known for their dynamics, and it doesn't sound like your amp is lacking power.  I imagine that Danny will be along and suggest a trouble shooting procedure.

[Danny Richie]

That's sounds pretty weird.

I have sent them way more power than that with no issues.

It is likely the amp giving out. It may only be playing at 50 to 100 watt continuous when it hits its peaks at 200 and then it clips hard.

And in room averages of 96 to 100db is pretty dang loud.

I am sure that they are fine, but put your ear to each tweeter to make sure each one is still playing and that you didn't hurt any of them.

[Jason Brent]

Something sounds off to me too.  I have what I feel is a less capable amp (200 x 2 vintage SS McIntosh) and significantly less efficient panels (83db) and can easily exceed that SPL in a similarly small room like KD's.

What source are you using KD?  What if some RF leaked in somewhere and damaged the drivers??  Even though their listed power handling is 50 continuous, I doubt they can handle 20k at that power....

[kingdeezie]

Something sounds off to me too.  I have what I feel is a less capable amp (200 x 2 vintage SS McIntosh) and significantly less efficient panels (83db) and can easily exceed that SPL in a similarly small room like KD's.

What source are you using KD?  What if some RF leaked in somewhere and damaged the drivers??  Even though their listed power handling is 50 continuous, I doubt they can handle 20k at that power....

Jason, I think we are misunderstanding each other....

Despite what the amps are or aren't capable off in relationship to each other, I am NOT talking about PEAK DB output.

We are talking about, for lack of a better term, MINIMUM DB output is 96-100 DBS. The meter I had didn't read anything over 105DB PEAKS at my listening position 10 feet away.

Theoretically, if I am getting 110 DB peaks at my listening position, then at 1 meter, the speaker is hitting 116 DBS. Given the efficiency rating at 1 meter of 91 DBs, that would mean that my amplifier would have to put out over 500 watts to hit that number...

Totally realistic that my amps are clipping since they are rated at 200 watts....

I remember you mentioning something being off because of dynamics with the LSes; this is why I was assuming you meant PEAKS, which is not what I am talking about when I mention DBS numbers. 

This was only happening during peak dynamic passages for which I have no numbers for. 

The more I think about it, the more I think its the amp. 

[Jason Brent]

Something sounds off to me too.  I have what I feel is a less capable amp (200 x 2 vintage SS McIntosh) and significantly less efficient panels (83db) and can easily exceed that SPL in a similarly small room like KD's.

What source are you using KD?  What if some RF leaked in somewhere and damaged the drivers??  Even though their listed power handling is 50 continuous, I doubt they can handle 20k at that power....

Jason, I think we are misunderstanding each other....

Despite what the amps are or aren't capable off in relationship to each other, I am NOT talking about PEAK DB output.

We are talking about, for lack of a better term, MINIMUM DB output is 96-100 DBS. The meter I had didn't read anything over 105DB PEAKS at my listening position 10 feet away.

Theoretically, if I am getting 110 DB peaks at my listening position, then at 1 meter, the speaker is hitting 116 DBS. Given the efficiency rating at 1 meter of 91 DBs, that would mean that my amplifier would have to put out over 500 watts to hit that number...

Totally realistic that my amps are clipping since they are rated at 200 watts....

I remember you mentioning something being off because of dynamics with the LSes; this is why I was assuming you meant PEAKS, which is not what I am talking about when I mention DBS numbers. 

This was only happening during peak dynamic passages for which I have no numbers for. 

The more I think about it, the more I think its the amp. 

I see.  Still, I'm sure that your amps are quite capable of generously exceeding their rated output in a transient. 

Sooo.......what amps are you looking at now? aa

[Stereodude]

First, I'd get your hands on a more accurate SPL meter.  Second, you need to remember that line sources do not lose 6dB every time you double your distance away from them.  Point source speakers do, but line sources do not.

My guess is that your LS-6's are damaged.

Have you tried another amp?

Why do you think the Neo tweeters are the source of the noise?  In my experience cracking noises tend to be from woofers, not tweeters.

[drunkonjack]

If it were the speakers I would think you would hear something before getting to the volume level you are getting to. But you need to get a more accuate .

I have turned my LS6's up using my Parasound HCA-3500 to power them and I'm the one giving up before the speakers or Amp start to show any sign of strain.

Good luck with finding the culprit.

[TomS]

Test one channel at a time.  Then switch the L/R pre channels, amps, or speakers one at a time to isolate each of those as possibilities.

I would be really surprised if the Odyssey's clip into the LS6's at anything less than unbearable listening levels.  My SE's drove the big SP Tech Revelations inside their 10k+ sq ft warehouse without problems.

[johnzm]

i know the sound he is talking about. i have heard it too.


KD, please pick up a db meter and report back.

when i heard this it truly was at UNBERABLE levels that i probably shouldnt have had the 'ol volume knob at.

altho when i did hear it, i assumed it was because of the bg's hitting a resonant and breaking up.

[Danny Richie]

The resonance frequency of the planar's is in the 250Hz range and is barely even a quarter of an ohm rise (not much of a resonance). Plus they are crossed off using a third order network at 1000Hz. So there is not much of a chance that they will hit any kind of resonance.

More likely than not you guys may be hearing clipping effects.

The output level of these will creep up on you and you won't realize just how loud they really are right up until your amp runs out of head room. Crossed over the way they are, they should be able to take more power than most of us have without issue.

Personally, I can only handle instantaneous peaks like drum hits or something at those output levels. Continuous levels at or near that 100db range is going to cause some hearing damage, so caution is advised.

[kingdeezie]

First, I'd get your hands on a more accurate SPL meter.  Second, you need to remember that line sources do not lose 6dB every time you double your distance away from them.  Point source speakers do, but line sources do not.

My guess is that your LS-6's are damaged.

Have you tried another amp?

Why do you think the Neo tweeters are the source of the noise?  In my experience cracking noises tend to be from woofers, not tweeters.

Understood, I know they only drop off 3 DB per doubling, but I sit at 10-11 feet. So 116 DBs at 1 meter (3 feet) would be 113 at 6 feet, and 110 at 12 feet. This is where I got my number.

I doubt my LS-6s are damaged. How would the issue be resolved by slightly turning it down then?? Wouldn't the cracking continue if the driver/drivers were truly blown?

I'll have to go get a radio shack meter at some point to test the output for real, and report back here.

[Jon Liu]

CW, you said you were using the iPhone's make-shift dB meter, right?  Do we know how accurate that is?  It may not be all that accurate and if that's the case, you could be pushing them even louder than you may be thinking, which may be clipping your amp (like Danny suggested already) before you think they *should* clip.  While 200 watts per channel is quite a bit, pushing the LS's to incredibly high volumes and sustaining them there seems it would require more power even still.  Outputting volumes at the frequencies that these things are capable of is most likely more tasking than one can imagine.  I don't know enough of the technical knowledge to explain my train of though, but that seems to make the most sense to me.