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what does overdriving speakers mean

Discussion in 'Home Cinema Speakers' started by whitewolf, Jan 13, 2005.

  1. whitewolf

    whitewolf
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    how does a person overdrives his speakers through which he can damange them?
     
  2. Londondecca

    Londondecca
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    By having the volume turned up to much :)

    Basically two ways

    1. Speaker has reached its natural maximum level

    2. Amp has reached its natural maximum level
     
  3. Reiner

    Reiner
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    Agree with Londondecca. One should note that it's easier to damage a speaker with an underpowered amp than driving them with a more powerful amp as this will cause the amp to clip (scenario 2. above). When clipping an amp outputs DC (direct current) as opposed to AC (alternate current) - and speakers don't like that.
    Since most speakers can handle short peaks exceeding their nominal rating a more powerful amp is unlikely to do harm when driven at normal levels (during normal use only a few Watt are needed).
     
  4. Beobloke

    Beobloke
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    Reiner is quite right, however of course if an amplifier that is too powerful is turned up too high for too long, then burnt-out voice coils can result, along with torn surrounds and suspensions in really extreme cases. (Londondecca's case 1)

    Tweeters are most susceptible to this.

    Adam.
     
  5. dynamic turtle

    dynamic turtle
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    Speakers are more delicate than you think. Try to be gentle with them if possible - don't be tempted to use them too loud. You could end up with an expensive pair of book-ends if you're not careful :lesson:

    I've certainly been a lot more gentle with my speakers after the B&W 601's died on me :oops:

    DT
     
  6. Lostinapc

    Lostinapc
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    i have the aegis evos 3 powered by a denon 1705. when i turn them up in stereo with the bass set to +6 i'll some times here the bass cone make a popping noise as though it has been pushed too far out. is that clipping or just the loudest the speakers will go?
     
  7. Kazman

    Kazman
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    PLUS 6??!!???!?? Dude, TURN IT DOWN!! You will kill your speakers!!

    What that is is destroying your speakers. Don't do it! :lesson: :rolleyes: :eek: :rtfm: :D
     
  8. Mason @ B&M

    Mason @ B&M
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    The popping means your amp is feeding DC into the speakers, so yes clipping. It's more damaging to tweeters than mids though...

    When you look at power handling of conventional cone speakers there are two factors to take into account: Thermal power hanlding and mechnical power handling.

    Thermal power handling is realistically the dirvers long term power handling in RMS.

    Its better on speakers with larger voice coils as they can dissapate more heat than smaller voice coils. Then you've got to consider the voice coil wire and venting, round wire isn't great as air can heat up between the windings of the voice coil. This is why a lot of manufacturers use flat and hexagonal voice coil wires.

    Mechanical power handling is more to do with what the driver can take for short bursts, most decent speakers will take large amoutns of power for a fraction of a second, but keep the power high and the voice coils would soon melt.

    Clipping and overdriving speakers by all accounts has similar effects, the cone is still moving so the voice coil is being vented and cooled, but as a clipped 50W amp can often produce as much as 100W clipped then a pure 100W would have a similar effect to the speaker.

    Basically a speaker dying means you've driven them passed their mechanical or thermal limits, if thats with a clipped or unclipped signal is doesn't make a huge difference.

    The advantage with clipping is that the speaker will sound terrible and make nice popping noises, so it's easier to tell that you're running clipped. It's much harder to tell that a speaker is getting too much clean power, but most home amps aren't potent enough to overdrive speakers in that way anyway.
     
  9. Dfour

    Dfour
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    :nono:
    :censored: Hell. If you want that much bass get a subwoofer!!!! I find my evos put out plenty of bass without increasing them. Maybe upgrading the interconnects and/or speaker cables will make some difference :suicide: You wreck those speakers you will be sorry :lesson:
     
  10. Lostinapc

    Lostinapc
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    thanks for that mason, i am hopefully going to get a stereo amp in the summer running from the outs of the denon so my music is better and has a bit more power.
    I don't think I'm running my speakers too hard... and they're under warranty for 3 years as well. i only turn it up near -10db twice a week for 10mins. it is nice to hear lots of bass on the occassion :p
     
  11. cityonfire

    cityonfire
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    The popping sound is most likely the drive unit has reached the end of its travel has i heard this quite alot when i used to sell them. Was running them on a Musical fidelity A3.2 amp and the customer just kept turning them up as there was not a hint of distortion and the drive units can not travel out anymore. And in terms of "They are under warranty for 3 years" just does not hold out. Acoustic Energy check all drive units to see if its a genuine fault. If it is they replace free of charge. If its not and the drive unit has been burnt out due to you turning up the bass(adding distortion much quicker at lower volumes) and volume too high they will charge you for a new drive unit. Lets be honest they aint going to pay for something you have done to the speaker yourself. And as Kazman said get a sub if you are wanting more bass.
     
  12. contactadam2002

    contactadam2002
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    (Regarding the Aeigis EVO3's straining under the stereo sound of the denon AVR1705).
    I have seen that happen many times before, different recievers will push speakers harder when the equalizer is turned up full compared to others. I have the EVO 3's myself and the main problem when you have the bass up too high is that the midrange drivers begin to strain easy as they are the smallest and output the most sound. Its hard for me to run them in stereo though as the reciever will easily take advantage and power the drivers up too much. In any case the best speakers to have where you can really run them at high levels are ones that either have 8inch+ drivers or horn drivers. Oh and if you tried playing a battle scene from a DVD with the sound on stereo and the bass up high then good luck cause they tend to strain even easier when its a pure 5.1 signal.
     
  13. Knightshade

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    Remind me not to buy secondhand from you guys.....:p
     
  14. brock_landers

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    LMAO, me too..
     
  15. Mason @ B&M

    Mason @ B&M
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    The problem with EQ's is if you boost a frequency by 3db you need double the amp power at the frequencies you're boosting...

    So if you're running your amp at near full power, boosting means you're introducing distortion and clipping.

    You don't need larger drivers to run loud though, I'm testing some small pods at the moment which we've developed to sound fantastic with large amounts of power, and they are efficient too... Then again they're going to cost a small fortune so in general I guess larger drivers are needed
     
  16. contactadam2002

    contactadam2002
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    Well if there are speakers out there that are small but sound good when pushed loud then I got to get some of them. You wouldn't happen to have a website for them would you?
     
  17. Mason @ B&M

    Mason @ B&M
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    I don't want to give too much away as they're still in development, plus I don't want to turn this into an advert as I might get in trouble..

    What I can tell you is the basics, under 2 litre in volume enclosures, down firing ported tuned to ~ 80hz. They are +-3db from 21K to 70hz.

    They're about 88-89db efficient and so far have taken 75WRMS per side, and as we ran out of power we drove the amp into clipping to see what happened, no problems as yet.. You don't need to highpass them at all.. In theory they should handle 150wrms, but I want to try that kind of level for a sustained period before saying they can actually do it.

    Mids/highs wise we've demoed them to a few studio technicians who have so far been very impressed, no music has stumped them yet, not even at high volume.. They're likely to be used mainly as monitor speakers, but we're hoping people might use them for home cinema too..

    The website is under construction, and as soon as it's ready I'll ask the mods about posting a link to it..
     
  18. contactadam2002

    contactadam2002
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    Hmm cool...so if you have been involved in the designs then your the guy to go to for adivce as you probably know loads on AV in general. If they really can go that loud then I'd definately give them an audition some time in the future. Small size big power... nice.
     
  19. Mason @ B&M

    Mason @ B&M
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    I know a decent amount about speakers, I wouldn't say I'm too hot on the rest of AV products as I've been out of the loop for a while..

    BTW, if you get bored work out how big a 2 litre enclosure is ;)
     
  20. contactadam2002

    contactadam2002
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    2 litre enclosure...never really thought or looked hard at those specs to wonder what that means in depth other than the fact that it's the volume inside the speaker. So I hope this isn't exceeding your mandate, but these speakers that you are developing..if they are monitor ones and you say that you tested them out at loud volumes are they the sort that will be able to make your ears ring and probably still be-able to go louder..you know like the effect you get after a disco for a real home disco/party experience?
     
  21. Mason @ B&M

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    If you ears are ringing then generally it's because you've been hearing distorted sounds, cleaner sound isn't so harsh on the hearing IIRC.

    I don't know if these would go loud enough for your tastes, I would hope so as they will go louder and cleaner than my Kef Q55's given the same power. Although for proper full range they will need to be paired with a sub as well.. If you've got any other questions on them drop me a PM..
     

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