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Diminishing power in my consumer electronics

Discussion in 'Recording' started by kmetal, Jun 2, 2014.

  1. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Hey all, I've notice recently that at some point within the first year of use, my and even my friends, consumer electronnics power amps/speakers seem to fade or settled down a bit. Whether it so my phone, my home theater, and recently my iPad, it seems to me that it takes a couple of extra notches on the volume dial, to get bit to the comfortable level I was used to initially. I understand the breaking period of speakers but I thought that it was about after 200 hours or so. This drop I'm noticing seems to take place after about a year. As a user of guitar amps and pro audio gear, it seems to be in my consumer based stuff. None of it is hi end, but not the cheapest stuff either. Somewhere in the realm of "decent"

    Just wondering if I'm going deaf or crazy, or if anyone has noticed this, or if there is some sort of technical reason for this.

    Thanks!

    -Kyle
     
  2. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

    200 hour break in?
     
  3. paulears

    paulears Well-Known Member

    Hifi speak. Breaking in period is the time it takes to suddenly discover the speakers you spent a fortune on don't quite sound right, and you need new ones. To stop embarrassment, they invented a phenomenon where speakers change sound once burnt in. Professional audio people of course believe it's total snake oil. Hifi people believe it absolutely right! You don't see many professional studios or broadcasters wiring their studios with esoteric cables, or running their new kit on full for days to run them in. We stopped doing that with cars years ago.
     
  4. Josh Conley

    Josh Conley Active Member

    his gear is fighting the loudness wars all by themselves? ;)
     
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  5. DonnyThompson

    DonnyThompson Distinguished Member

    I've heard of break in, but not 200 hours of it.

    The people I've talked to who believe this to be fact, spoke in terms of minutes, not hours, where a sine wave equal to that of the natural resonance of the speaker/cabinet was played at an average listening level (80-85db) for 10 - 20 min or so.

    Some believe that "break in" refers more to the listener getting used to the new speakers, in the environment in which they are used, as opposed to the speaker itself "settling in".

    I do understand the theory that because speakers are mechanical in nature ( there is physical movement), that this would suggest that they can wear over time, like any other moving part can.
    And, I've seen measurements that back that theory up, but, these appear to me as minutia for the most part, and not measurements significant enough that I myself could claim with any honesty to actually hear.

    I won't go so far as to call it snake oil or balloon juice. Those that believe it to be true may indeed be right. I'm just saying that I can't back it up. My Monitor 1's sound the same to me as they did from the moment I first connected them 16 years ago... although the sound of my mixing environment(s) have certainly changed over time.
     
  6. Josh Conley

    Josh Conley Active Member

    i suppose looking at the "moving" parts on a speaker you have an energy conversion at the speaker cone itself, which causes fatigue over time where the cone connects and flexes. could that be a source of change?
    also, the material used for the cone. is it breaking down? i recall as a kid wondering why some peoples cone edges started dissappearing intoba cloud of dust. clearly mfg techniques have improved, but is it still a factor?

    also, all power sources have electrolytic caps, and those leak.

    lots of maybes.
    i think some killing joke is in order to ponder properly...
     
  7. paulears

    paulears Well-Known Member

    That's the thing. Psyco-acoustics experts seem to agree that belief is a strong motivator for hearing things. I suspect that maybe his hearing really is changing gradually, so revisits to a particular sound strike him as different. I've been plotting my hearing quite unscientifically for a while, and it certainly is changing!
     
  8. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

    It takes seconds. Once the varnish impregnating the spider loosens up the driver is essentially stable for years. Heat from hard use within the design's known limits can slightly change the performance of the spider and voice coil, but the driver recovers when it cools.
     
  9. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Well hopefully my hearing isn't degrading that fast, lol a few months, geez.

    I refer to the 200 hours, cuz whenever I've read (ut oh dangerous) reviews in the mags when headphones and speakers are concerned, they usually say they run music for about a week straight at average listening level, before they review them. One dude, I forget who basically was saying that they need to loosen up a bit, because when the cone is tight, it has lesser bass response, and dis proportional highs, relative to how it will sound "broken in", which is how it will respond for quite a while after.

    Hmm maybe I'm just imagining it. If I none of you guys have noticed this, that's probably what it is, my imagination.

    As far as snake oil and hifi vs pro audio, I've personally never heard a diff in cables, other than if one was noisey or whatever. But chuck ainly, swore he could hear a difference when he used all gold audio and power cables on Allison Krauses latest album, he also had some custom mods done to the 192 I/O he was using, beyond just what BLA would do. I'll believe it, or not, when I hear it, until then, I'll focus on keeping my gas tank full.

    Thanks.
     
  10. paulears

    paulears Well-Known Member

    I've never read this kind of thing in pro audio magazines, but sadly it's often a hot topic in mags for audiophiles.

    I was at a presentation by Sennheiser a few years ago, and they did an interesting demo. They switched between two sources while we were listening and everyone heard the difference. Their technical guy explained that it was caused by X and Y, and one cost X and one cost Y. This took a minute or two. He then played the first one again, and told us this was X. He then explained he'd now play the same track on Y, the more expensive machine. He asked for comments. Some people concluded the small difference was worth the extra money, others considered it too small to make it cost effective. He then told everyone that what in fact they had heard was the same machine twice, and it was the cheaper one. He pointed out that with a gap between two, your memory is not reliable enough, and the small differences we all were convinced we heard were due to expectation, not reality. Some people had been very critical of the people who were having trouble hearing the differences. It was quite sobering. With the instantaneous switch, we could hear difference in the overall sound, but it was small - and this tiny difference was in practice small enough to be imagined when we were listening with a gap in between.

    I believe that the hi-fi people really do believe they can hear these things, but in fact, many of their comments are based on pretty decent scientific common sense, rather than listening acuity.

    I've been watching my top limit creeping steadily downhill - I'm 55 now, and cannot hear at all 16KHz. It isn't just quiet, it's gone. In a year it's dropped from 16.5KHz. Not much, really - but two years before that I could hear 17KHz. Oddly, though - I can still hear the usual sizzle on the cymbals, and the fingertip rub I always used to generate HF. It's also only the harmonics on a few notes on the piano keyboard.

    On my phone I now have a 16KHz tone and on a crowded train or somewhere where kids are annoying me, it's great fun to push play and sit in silence seeing them all squirming. Losing top end does have some benefits!
     
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  11. DonnyThompson

    DonnyThompson Distinguished Member

    I'm still okay at 16k, - although I'm sure it's diminished as 55 years has gone by....but I've got nothing above that. Nothin'.

    What Paul's example showed was pretty much what I've suspected - in terms of these esoteric additions - for quite sometime now... and that is that the power of suggestion is a serious power indeed.
     
  12. DonnyThompson

    DonnyThompson Distinguished Member

    You are a cruel, cruel man. Give me a few years to lose 16k and I'll sit on the train with you. ;)
     
  13. Boswell

    Boswell Moderator Distinguished Member

    This is an excerpt from an RO post I made in October 2012:
     
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  14. DonnyThompson

    DonnyThompson Distinguished Member

    "My last audiometric tests gave a figure for my ears of around 15KHz, yet I can easily tell the difference between a 7KHz sinewave and a 7KHz squarewave, where all the differences between these two are at 21KHz and higher."

    I'm confused ... because two separate types of waves are being used, are there not also audible harmonic differences within the "average" range of perception that allows us to tell the difference, as opposed to only the upper frequency-dependent difference(s) you mentioned?

    "I can also tell the difference between the same transient waveform sampled at 44.1KHz and 96KHz, particularly where the source is something like a pair of Tingsha bells..."

    I don't believe that I can... I don't think that I could hear the difference between 44 and 96k anything for that matter. Maybe, but probably not, based on recent past experience.

    I'm not doubting you Bos... not at all. I'm positive that there are more than a few people like yourself who can hear those differences. I just don't believe that I am one of those people.

    Which leads me to the question of whether I might need to consider finding another line of work... no joke.
     
  15. Boswell

    Boswell Moderator Distinguished Member

    No, not if the transducers (headphones, loudspeakers etc) are linear. I was careful to set up the level so that the amplitude of the fundamental (7KHz) was the same in both cases.

    Quite often these things are not one of belief of what you would hear but of what you do actually hear if you perform the test. I was surprised at how much difference there was in this case. However, bear in mind that the original post was in a thread concerned with sampling and mixing at 44.1KHz versus sampling at 96KHz followed by analog mixing and re-sampling at 44.1 KHz, so the effects of things like anti-aliaising filters play a major part in this.

    Note also that these differences are all about technology and not about the human hearing system. If the test had been a live tingsha bell versus a recorded one, there would have been more difference, but let's just say that the 96KHz recording+replay was closer to the original than the 44.1KHz.

    To get back to the original point, conventional audiometric tests give the results for only one aspect of the human hearing sytem. We in the pro audio field are concerned with how equipment sounds over all the aspects of hearing. It's like not choosing your gear purely on its paper specifications - you need to hear it first.
     
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  16. DonnyThompson

    DonnyThompson Distinguished Member

    "...To get back to the original point, conventional audiometric tests give the results for only one aspect of the human hearing sytem. We in the pro audio field are concerned with how equipment sounds over all the aspects of hearing. It's like not choosing your gear purely on its paper specifications - you need to hear it first..."

    I couldn't agree more. Back when I worked retail ( early 1980's), part of my obligation was to study the spec sheets of all the products in my department (audio recording). I had to know stuff like the bandwidth of a Tascam MS16, or the bit resolution of a Yamaha SPX 90, that kind of stuff. I did it because that's what the boss told me to do, so I was always taking home data sheets to read in bed.

    The thing is, I'm not sure I recall even one specific incident where I was asked about the Tascam's alignment/biasing specs, or the bit resolution of a Rev 7, or the SNR of a Fostex B16...

    What I did get a lot of, were requests to hear the gear.

    The boss used to roll his eyes at that... I tried explaining to him that the specs were of little concern to the consumer, and that while it was important to have that data at hand in case we were asked, what the customer really wanted was to hear how the gear sounded, to actually hear how well a particular model did what it was supposed to do.

    His mentality was that a "true pro" would care very little for anything other than the specs. "Specs don't lie!" is the answer I always got when I objected to his logic. Yeah...to be sure, he was very myopic.

    He did eventually see - or at least, got a glimpse of - what "true pros" wanted, when one day, a well known, big label producer came into the store, to buy a digital reverb for recording purposes.
    The boss went directly for the spec sheets (of course), and was told quickly by the customer - "Nah, I don't care about that stuff. Let's just plug a few in and see how they sound."

    I had him eatin' a lot of crow that day, but he never really did see the light. In short order, he went back to his data sheets, and proceeded to bore the living s h i t out of the natives with his bland, droll, regurgitation of "specs". ;)
     
  17. kmetal

    kmetal Kyle P. Gushue Well-Known Member

    Geez why would anybody want to know what they're audio gear sounds like before they buy it? And manufacturers are always completely honest, and unbiased when setting up the tests for theirs specs. I'm waiting for the day a "flat" iPod Dock comes out, w 2" speakers.

    I'm not really very technical w electronics, but I would have to guess that the quality of the converters would be a factor in how different sample rates sound.?
     
  18. MrEase

    MrEase Active Member

    I think this may be optimistic but maybe not by much! The big assumption though is that there is always a varnish impregnated spider locating the voice coil and takes no account of the outer suspension of the cone. For example, in my home system I have some B&W speakers that, on the mid range, have a suspension that is apparently balanced by a screw on the back of the speaker which must be correctly tensioned in use and slackened off for transport to "lock" the cone. Also it has no discernable outer suspension other than a single return on the kevlar cone. The manufacturer themselves say that this suspension will take up to 200 hours of normal use to "settle" and that subtle changes will occur during the process.

    Of course this is a very different construction to most but cone suspension varies on a raft of speakers. There are certainly many other spiders other than impregnated corrugated cloth and also a variety of outer suspensions from rubber mounts to several corrugations of paper with several other methods inbetween.

    It is simply not possible to give a general rule on any "running in" time for speakers due to this variety.

    What is certain though is that all the differing ageing processes will result, if anything, in a reduction of "stiffness" in the suspension and this would not lead to a reduction in volume as per the OP.

    Any true reduction in volume as reported would surely be a result of some degredation or fault within the driving electronics.
     
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  19. MrEase

    MrEase Active Member

    Sorry to continue with the mild hijacking of the thread but I also have to reinforce Boswell's observations about tonal differences heard when harmonics are "out of range" on normal hearing tests. Sadly, having benefitted in my youth form 20:20 vision and very good hearing (measured aged 19 in my uni's anechoic chamber) things have changed somewhat!

    At the age of 59 I now have to select which glasses for computer or reading and have also blasted my hearing somewhat down to 12-13 kHz. The worst part is that my left ear has fared relatively poorly. What is noticeable is that, in normal circumstances I don't perceive a L-R imbalance. This is not quite so in a noisy background environment when I can find it hard to follow some conversation on my left side. I put this down to my right ear not getting "clean" information due to the noise but I find the psychoacoustics of my predicament interesting.

    With such poor hearing now, I would expect that I would be severely hampered during the mixing process but strangely I do not feel this is the case - unless others are just being kind! I have put this down to a similar perception as that given by Boswell.
     
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  20. Boswell

    Boswell Moderator Distinguished Member

    This extract is from a Wikipedia article on Thiele/Small parameters relating to loudspeakers:
     

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