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Woofer damage from new Star Wars THX DVD?

Both woofers in my JM Lab Utopias blew with the THX intro (exploding sphere) on the new Star Wars DVD. Happened at normal listening level through my Theta Casablanca II/VTL 7.5 preamp/Halcro dm58 amps. I've not blown a driver in over 30 years of being an audiophile. I've heard that the base was boosted as much as 36db on some of these DVDs. Even though the speakers are under warranty, I'm out $1,200 for a new Focal woofer (JM Lab only covers 1 driver for this kind of damage). Anybody with information or suggestions? Needless to say, I'm not happy about eating this expense if the fault really lies with an overmodulated DVD with no warning about increased bass levels. At the verey least, I'm curious to see if this happened to anyone else. The sound level was high enough that the concern for hearing loss came to mind (I'm a physician and I don't think I'm this concern is frivolous). Thanks for any thoughts or other input.
avimar

Showing 2 responses by sidssp

sidssp
1,077 posts
 
I don't watch too much movies so I don't really know what reference level is correct but I think if you listen at over 100db level, you might be risking yourself to permanent hearing damages.
sidssp
1,077 posts
 
Spluta,

You said 75db do you mean the display on your preamp shows 75db? If so, that is not how the setup works. You can not go by the number on the display because different power amps and speakers have different sensivitives. You need to run a test signal and measure with a SPL meter at the listening position. Someone said it should be 85db, some said 75. I don't know what is right but I will go by the lower number just to be safe.

On the other hand, if you did measure with a SPL and your speaker begain being stressed than I think your room maybe too large for your speakers. A speaker should not show stress at 75db at the listening position.

My comments were based on what I understand from your message. I could be totally wrong here because I don't quite understand what you meant by 100db for busy redbook and 105db for DVD-A.
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