Blown Speaker?...Not Really

Discussion in 'Amps and Cabs [BG]' started by mech, Oct 23, 2017.


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  1. mech

    mech In Memoriam

    Jun 20, 2008
    Meridian, MS, USA
    At a recent outdoor gig with no FOH support I was using a 410 (4 Ohm) with 500W full range and a 210 (8 Ohm) with 250W as a sub. Both cabinets are about 25 years old. During the gig the 210 gave a squawk and quit working. Figured I'd burned a voice coil. Pulled the speakers today and found a broken tinsel wire. Great! Not the first time I've seen this and it's an easy repair.

    Spliced in some 18ga wire that gave plenty of slack and a better angle for the tinsel wire to move and back in business. Saved $200 on new speakers and it's good for another 25 years.

    First pic is the break and the 2nd is the repair.
    tinsel wire break.JPG tinsel wire repair.JPG
     
    murphy, JimmyM, kartiste and 2 others like this.
  2. Weird choice of cab for a sub.
     
  3. bobyoung53

    bobyoung53 Supporting Member

    You're lucky it didn't pull out of the cone, happened to me once years ago with a JBL D-140.
     
    mech likes this.
  4. mech

    mech In Memoriam

    Jun 20, 2008
    Meridian, MS, USA
    Big 210...half the volume of my 410. Works great for me. Your mileage may vary.
     
  5. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Possibly a contributing factor to the damage.
     
    staccatogrowl likes this.
  6. FunkHead

    FunkHead Supporting Member

    Mar 10, 2007
    Maybe you could solder in some spring steel for the really long notes.
     
    staccatogrowl, 58kites and mech like this.
  7. mech

    mech In Memoriam

    Jun 20, 2008
    Meridian, MS, USA
    tinsel wire break-text.jpg
    Please note that in the original post I state that the cab/speakers are 25 years old and only powered by 250 watts. If you look at the pic with the break you will see that solder had wicked all the way down to the bend during the manufacturer's soldering process. The flexible part of the tinsel wire tugged on the inflexible soldered portion for 25 years causing the break. The positive lead and the leads on the other speaker are fine.

    It would also help if you had actually heard a rig before critiquing it.
     
    58kites likes this.
  8. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Excuse me sir, there's more to this then you are (incorrectly) assuming.

    Before you make such a snarky and undeserved comment, just MAYBE you might be interested in the history of WHY this sort of thing happened to you and the reasons behind this failure. I was directly involved in this particular failure mode within the industry AND with some of the industry changes that eliminated this as a common failure point.

    The drivers of this era (specifically Eminence, but many others used this practice as well), the designs were all low powered (mechanically) by today's standards. Xmax was in the 2.0-3.5mm range which improved sensitivity (important with the lower powered amps of the day) and Xlim was not all that much greater (by comparison to modern designs). This means that the tinsel wires and the cone edge where bonded to the surround were the two weakest areas of the driver (followed by bobbin/VC adhesives).

    These parts suffered from fatigue when driven beyond their mechanical power handling (which may be less than 50% of the thermal power rating at low frequencies) causing excursion well past Xmax for even moderate power. This puts added mechanical strain on the tinsel wire which, when coupled with resonance of the wire (the thinner wires of the past exhibited the nasty tendency of sympathetic oscillation) greatly reduced their life as they were no longer operating in their linear region. The cone edge failure was similar, the geometry of the junction of many (not all) drivers of that era created a discontinuous transition at that location which suffered from fatigue under exactly the same conditions.

    The changes in driver construction to correct for these weaknesses were to migrate to a thicker, fiber reinforced tinsel wire that could be made slightly longer without suffering from resonance, and to change the cone edge geometry from a flat to angled joint, with slightly thicker cone material. This greatly improved the stress profile, reducing the fatigue at this point as well.

    Virtually all bass drivers used in the industry today incorporate these changes to eliminate the very problem you experienced. Even the recone kits will typically incorporate these changes because the problem was very real and had nothing at all to do with the solder joint. Your driver contains both of these known issues.
     
  9. murphy

    murphy Supporting Member

    May 5, 2004
    Canada
    Hmmm...perhaps also explains the cone crease problem when I played Eden tens XLT cabs?....Back in the day
     
    staccatogrowl likes this.
  10. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Quite possibly. This was a common failure mode in all early bass drivers with the flat cone edge. I can't think of any modern drivers built this way.
     
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  11. mech

    mech In Memoriam

    Jun 20, 2008
    Meridian, MS, USA
    @agedhorse ....The purpose of the original post was to help fellow bass players who have sufficient skill at soldering save money and time. Your invitation to a pi$$ing contest about component construction and the proper use of gear is cordially declined.
     
    58kites likes this.
  12. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    For bass players who want to LEARN about this stuff, and there are plenty of folks on TB who fall into this category, understanding the history of WHY things fail which leads to newer products incorporating changes to address design weaknesses is valuable to making better purchasing and repair decisions. Also understanding why it's possible that excessive power at low frequencies over time might have contributed to the cause is in fact highly likely, even if you do not agree. Extensive ageing testing for fatigue was directly related to the low frequency mechanical power handling of the driver, specifically the tinsel wire and cone edge. Later designs addressed both of these items because root cause analysis showed them to be the weakest links.

    Your postulation of why your failure occurred is almost certainly (like 99.9%) wrong based on my extensive experience with this specific industry problem which I worked on personally. Falsely calling out or postulating an incorrect cause is not helpful to other players trying to learn more about this issue.

    If you bring inaccurate of bad information to a discussion, you need to be prepared to either defend it or admit that maybe you jumped to an erroneous conclusion. It has nothing to do with a pissing contest, at least not on my part.
     
  13. I have personally had three, (for sure), failures of this type on the Aguilar GS112 cabs I used for several years. One repaired by a shop the other two by a tech friend. I'm not sure what Aggie used, Emenince, ? Most of the time I was driving them hard with a 440 watt Glock Soul II, a Carvin bx500 then a Genz Shuttlemax 12, for what it's worth.

    Oh and someone needs a snickers, they're not themselves.
     
  14. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    This was a very common problem Kirk, as amps became more powerful along with the desire for more low end extension. I don't think any quality higher powered bass guitar driver these days used the old cone geometry or thin unreinforced tinsel wire. Just too vulnerable to excessive warranty claims.
     
    staccatogrowl likes this.
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