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Thread: How loud can I go?

  1. #31
    RothwellAudio Guest

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    It may be useful to consider the failure mechanisms for loudspeakers.
    Firstly, a voice coil could get so hot that the wire literally melts, like a fuse. The wire isn't very thick, so melting it isn't impossible. The heat tends to build fairly gradually and dense music with lots of sustained bass is likely to have a strong heating effect on woofers. Tweeters have thinner wire than woofers but generally don't have to cope with a lot of heat. But an amp could go into ultrasonic oscillation or be fed from a pre-amp generating ultrasonic frequencies which would fry a tweeter fairly quickly and you wouldn't even know (because it's ultrasonic) until it's too late.
    Secondly, the voice coil could get very hot but not hot enough to melt the wire. Instead the voice coil former and the glue holding it together get so hot that the voice coil looses its shape doesn't move backwards and forwards cleanly in the gap it's meant to fit, and it scrapes or even gets stuck.

    A second type of failure mechanism is due to transients forcing the cone to move - or attempt to move - too far. In this case wires can be snapped rather than melted.

    Anyway, I don't think there's a reliable way to measure or calculate anything that will tell you which spot on the volume control's travel is the safe upper limit. My advice if you like your music loud is to use high efficiency speakers, maybe 96dB sensitivity or more. Don't put a pair of BBC LS3/5As on the end of a 500W amp and wind the wick up as far as it will go

  2. #32
    Join Date: Aug 2011

    Location: Coventry, England UK

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    I'm Simon.

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    It's a bit of common sense though... surely? (without getting technical of course)

    I know odd things can happen but if one uses a decent powerful enough amp/s for the speakers and listens within a sensible level in regards to it's size then there shouldn't be a problem. Like Andrew mentioned above with the BBC 3/5a's.

    Also, it shouldn't matter about db settings on amps as they will all be different anyway. Always trust the ear first and foremost, if it sounds too loud - it probably is! My current (and forthcoming) pre don't have any level settings or fascia markings, other than an indicator on the dial. I know where my preferred listening level is for all formats, be it CD, LP and whether it is a modern compressed mess with DR6 or an older DR13.

    I know I like to crank mine when the neighbours are out and I know it's loud but not too loud that it causes fatigue or ringing in the ears (if ringing happens, it is blatantly too loud imo).

  3. #33
    Join Date: Oct 2012

    Location: NE England

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    I'm Jez.

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    The problem is the logarithmic nature of human hearing... this is why it can be easier than one may think to blow drive units. 1Watt is actually pretty loud but if you want it to sound twice as loud then you need 10W. You can see where this is going... The 10W sounds good and rockin out loud but you think "just a bit louder"... and what sounds to you just that bit louder has now gone from 10W to 70W...
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  4. #34
    Join Date: Oct 2012

    Location: NE England

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    I'm Jez.

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    Quote Originally Posted by Pharos View Post
    "I'm aware of the concepts and consider them hugely over rated actually. Have you heard of the concept of knowing what you are talking about before posting myth as fact? "
    Yes AE, the first part is fairly evident now I think about it.

    I stand by what I said, and I do analyse my thought processes not only in electronics, but in all else.

    With a manufacturer's specified maximum spl O/P for a speaker, an spl meter is of use in knowing whether or not one is approaching the maximum limit of I/P power to a speaker.

    I have formed the impression that you overate yourself and also are rude.
    Try analysing it and coming up with the correct conclusions then... I've explained in a previous post just why one very definitely cannot use a SPL meter to determine max safe volume. As to the personal insults well you know what you can do pal. I shall add you to my ignore list as I'm sick of reading utter rubbish presented as "insightful" (ha) fact.
    Arkless Electronics-Engineered to be better. Tel. 01670 530674 (after 1pm)

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    ReVox PR99, Studer B62, Ferrograph Series 7, Tandberg TCD440, Hitachi FT-5500MkI, also FT-5500MkII
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  5. #35
    Join Date: Aug 2011

    Location: Coventry, England UK

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    I'm Simon.

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    Quote Originally Posted by Arkless Electronics View Post
    The problem is the logarithmic nature of human hearing... this is why it can be easier than one may think to blow drive units. 1Watt is actually pretty loud but if you want it to sound twice as loud then you need 10W. You can see where this is going... The 10W sounds good and rockin out loud but you think "just a bit louder"... and what sounds to you just that bit louder has now gone from 10W to 70W...
    True, didn't think about it like that (just turned mine down a notch haha)

  6. #36
    Join Date: Aug 2009

    Location: Staffordshire, England

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    I'm Martin.

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    Do manufacturers ever specify a 'maximum spl'? I've never seen this. Only maximum power handling. Which manufacturers give max spl figures? And do they specify at what distance? Otherwise it is pretty meaningless.
    Current Lash Up:

    TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.

  7. #37
    Join Date: Feb 2008

    Location: South Wales

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    I'm NotTakingLifeTooSeriouslyTheseDays.

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    Most reputable speaker drive unit manufacturer used to state Max SPL figures as well as Max power handling, one could easily establish then for eg, if a drive unit had a maximum SPL of say 114 db, and a sensitivity of 96 db per watt, per mtr, then well,,,I am sure most will understand where I am coming from on this...
    Distortion, and paticularly certain aspects of distortion can be a tel tale sign that something is too loud, however, when you have an amp that has lots of clean power, then it can be quite easy to reach SPL levels not only damaging to the drive unit, but to long term human hearing too!
    Quote Originally Posted by Macca View Post
    Do manufacturers ever specify a 'maximum spl'? I've never seen this. Only maximum power handling. Which manufacturers give max spl figures? And do they specify at what distance? Otherwise it is pretty meaningless.
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  8. #38
    Join Date: Aug 2009

    Location: Staffordshire, England

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    I'm Martin.

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    So this was something that used to happen back in the dim and distant then? Can't say I have ever seen drive units, reputable or otherwise, quoted for max spl.
    Current Lash Up:

    TEAC VRDS 701T > Sony TAE1000ESD > Krell KSA50S > JM Labs Focal Electra 926.

  9. #39
    Join Date: Oct 2012

    Location: NE England

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    I'm Jez.

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    Quote Originally Posted by Macca View Post
    Do manufacturers ever specify a 'maximum spl'? I've never seen this. Only maximum power handling. Which manufacturers give max spl figures? And do they specify at what distance? Otherwise it is pretty meaningless.
    Some do yes. It is pretty meaningless unless very tightly specified though and even then there would need to be a standard for comparing different speakers.
    It can usually be assumed that any such measurement will be taken at 1M, on axis (usually tweeter axis), and in an anechoic chamber. The signal used for testing is critical as well of course! Do you use music? If so what track? Averaged out over what time?
    Single frequencies are useless as the practical power handling of a speaker varies massively with frequency. Pink noise is probably the best signal overall.

    When one reads that a speaker has a power handling of say 100W it is a very, very loose approximation! Even the woofer will probably handle nowhere near that much if it is a continuous sine wave and the tweeter maybe 10W or so (I'm picking "typical" figures out of the air here so please pedants don't bother looking up the tweeters used in your own speakers to report back that "my tweeters can handle 18.4W" etc). The specified figure can usually be taken as using fairly uncompressed music and not either dub reggae or a penny whistle solo but something that represents "typical music" and spreads the load in a "fair" manner between the drive units. It is also assumed that no clipping occurs of course. Due to thermal time constants it takes a while for a voice coil to heat up and therefore a woofer may take short bursts of say 500W for a second or two even though 30W continuous may blow it. All this is taken into account in giving what is really only a generalised estimate of safe power handling... It is so generalised that one company may give a figure of "100W power handling" for a speaker that another manufacturer would claim only 50W for and a third would claim 150W... It is that "unscientific".
    Very often the phrase one sees is "suitable for use with amplifiers up to 100W"... extrapolating from the above, this does not mean the speaker will take a continuous 100W. It means that on this mystery generic typical music track a 100W amp could reach 99.9W (not clipping) ON PEAKS, individual kick drum beats, brief crescendos etc, with little chance of harm. It is "cheating" in many respects as it also takes advantage of the peak to mean ratio of the uncompressed music... the output of the amp may well be averaging, over several seconds or a minute, only 10W or so.

    Very rarely one may see a more rigorous specification given... usually something like "The speaker is specified as being able handle 100W of unclipped "A" weighted pink noise when applied to the speaker in a regime of 5 seconds on followed by 10 seconds off and for a total test period of 30 minutes at 20C ambient temperature".... something on those lines would be the most scientific specification of power handling I've personally seen. Now try using that to decide just how loud you can safely blast out that AC/DC album... Good luck with that
    Arkless Electronics-Engineered to be better. Tel. 01670 530674 (after 1pm)

    Modded Thorens TD150, Audio Technica AT-1005 MkII, Technics EPC-300MC, Arkless Hybrid MC phono stage, Arkless passive pre, Arkless 50WPC Class A SS power amp, (or) Arkless modded Leak Stereo 20, Modded Kef Reference 105/3's
    ReVox PR99, Studer B62, Ferrograph Series 7, Tandberg TCD440, Hitachi FT-5500MkI, also FT-5500MkII
    Digital: Yamaha CDR-HD1500 (Digital Swiss army knife-CD recorder, player, hard drive, DAC and ADC in one), PC files via 24/96 sound card and SPDIF, modded Philips CD850, modded Philips CD104, modded DPA Little Bit DAC. Sennheiser HD580 cans with Arkless Headphone amp.
    Cables- free interconnects that come with CD players, mains leads from B&Q, dead kettles etc, extension leads from Tesco

  10. #40
    RothwellAudio Guest

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    Quote Originally Posted by anthonyTD View Post
    ... and a sensitivity of 96 db per watt, per mtr, then well,,,I am sure most will understand where I am coming from on this...
    Yes, I think so. If you put one watt in and stand 1 metre away you'll hear 96dB. If you put two watts in and stand 1 meter away you'll hear 192dB. If you put two watts in and stand two metres away you'll hear 384dB. The poor buggers standing 3 metres away were vapourised before you had time to turn round

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