Two Acoustic Energy Evo 3s have blown ??

Discussion in 'Home Cinema Speakers' started by pigsy7, Jan 10, 2008.

  1. pigsy7

    pigsy7
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Hi, okay here's my story.

    Have a home cinema setup with a full set of 2x Acoustic Energy 3s 2x Evo 1s 1x Evo centre and 1x Evo sub woofer.

    Okay so far so good. Problem though is I've just noticed that not that long after buying them .. just a few months, the mid range woofer on both of the Evo 3s at the front have gone. Well, one is totally dead and I've checked it's now actually "open circuit" and the other has ripped itself free of the "spider" and so is on the way to self destruct, and currently makes a horrible scratchy ripping tearing noise when being pushed moderatly.

    Now to clarify I temporarily nicked the same mid range driver unit from both of my Evo 1s and put them into the Evo 3s which I thought would basically fix them, which of course it did, but if I turn the volume up fairly high, you can see that they are eventually going to go the same way .. it's as if the cross overs on BOTH Evo 3s are faulty ?? as the mid renage units try to virtually pop out of the speaker cabinet. Not right surely ?

    For info, the amp is a Sony STR DA 3200 with Max 120 watts per channel, and the Evo 3s are rated at 150w each ?? so in theory I can't blow them using this amp ? can I ?

    One last noob question, why do amps use db ?, I mean I understand what Decibels are etc, but why does it start as a really low -db and at 0db it's fairly loud, and goes all the way to +37db if I recall ?, that really confuses me !

    Thanks in advance for any help received !!

    Jim
     
  2. Badger0-0

    Badger0-0
    Distinguished Member

    Joined:
    May 30, 2005
    Messages:
    20,601
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Spaghetti Junction (really)
    Ratings:
    +1,922
    Your amp might say it's capable of 120W per channel, but the reality is it might only be half of that. One of the worst things you can do to a speaker is underdrive it and whack the amp full up, as it introduces massive distortion.
    You shouldn't really turn any amp full up.
    I don't know how loud you use it, but seeing as you know it goes to +37, I'm guessing you do run it full belt sometimes.
    If that's often, I'd say that's probably the cause.
    Having said all that, I would have thought your amp and speakers are a reasonable match and if anything, I would have expected the tweeters to have blown first. It might be worth getting in touch with AE and asking them what they think.

    As for the dB range, well the idea is you use 0dB as a reference point to set your speakers to 75 or 85 dB as per the THX guide lines.
    My Denon amp runs from -80dB to +6dB, I think.
    I wouldn't worry about it too much.
     
  3. Peter Galbavy

    Peter Galbavy
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I have much the same setup, but I replaced the EVO sub with a Monolith. I drive the fronts with a Denon 4306 at high levels and have (luckily, so far) not had any problems like you describe. I bought mine 2nd hand through these forums and they are now about 18 months old in total.

    I do bi-amp them as I found that driving them from just the front channels of the Denon gave me distortion anywhere near reference levels (-5dB and I could hear "scratching").

    Perhaps if the Sony amp is clipping it is causing the drivers to do odd physical things...
     
  4. Crustyloafer

    Crustyloafer
    Well-known Member

    Joined:
    Sep 12, 2003
    Messages:
    9,577
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Edinburgh
    Ratings:
    +1,269
    Yes you can easily. That very statement by yourself indicates a fundamental lack of understanding of how amplifiers work and how speaked damage can occur. Basically your amplifier has not got the power reserves to drive those speakers at the volumes you desire without clipping. Amplifier clipping is what predominantly damages speaker drive units. More on clipping here.

    http://en.wikipedia.org/wiki/Clipping_(audio)

    Looking at the specification sheet of your amp, it is listed as having 7 channels of amplification cabaple of 110 watts into a 4 ohm load. It is very unlikely indeed that it can supply this sort of power to all channels simultaneously. Driving all 7 channels into an 8 ohm load I would be very surprised if it could muster up any more than about 25 watts to each channel simultaneously. Running that amplifier into those sort of speakers, particularly if they have been configured as 'large' speakers in the amplifier's settings, is almost certainly going to cause the amplifier to start clipping at volumes anywhere near 0dB or above and as a result will damage your speakers.

    Conclusion, your speaker damage has been most likely caused by driving your speakers too loud with an underpowered amplifier. This constitutes misuse and alack of care and attention and as such the damage wil not be covered by any warranty. Luckily the AE speakers are pretty cheap and as such the replacement parts will also cost very little. I wouldn't expect a bill of any more than £80-100 for all the bits you need.
     

Share This Page

Loading...