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Speaker/Speaker wire?

Discussion in 'Amps and Cabs [BG]' started by Esquillama, Sep 25, 2005.

  1. OK. So last night we played at a casino for a private party.
    After we set up we had about 2 hours before we started.
    I was checking my tuning and sound, and heard a buzzing sound
    coming from my 2x10(the only cab I had with me).

    I took off the back panel to check and see of all connections
    were tight, and still heard it. So I took off the front grill and
    unscrewed the old speaker(I've replaced one of them about
    3 years ago), and checked all connections on both speakers.
    Everything was tight, so I unplugged each speaker individually,
    just to isolate and see which one was having the problem.

    Turns out the old speaker was ONLY giving out the light buzzing.
    The only real sound was coming from the new speaker.
    I have a suspicion that this has been going on for a while now,
    because I've been unsatisfied with my tone for quite some time.

    So I played the whole night with only one 10" speaker.
    My peak light was coming on a lot on my power amp,
    and when I got done for the night, I unplugged the speaker
    cable, and noticed that the 1/4" plug was warm!
    I've never had this happen before.

    I'm guessing that it's because of only one of the speakers
    being useful(they were both still plugged in on the inside).
    And I'm ordering a new 10" speaker to replace the old one.

    It's a Carvin 2x10 from about 1992 or so.
    Does anybody know if I might have done any harm to the
    "good" speaker by using it this way?(I hope not)
  2. You did just change the impedance ( ohms ) of the cab by removing a speaker, which may be ok, or may not be! (depending how they are wired, what they are individually etc )

    Did you just get the first 10" speaker that came along or did you look into them and get one that would be in tune with the cabs volume?
  3. I replaced it with another Carvin 10" speaker.
    The same as the one that was in it, only the new version.
    Still 200 watts.
  4. IMO it is unlikely that you harmed the speaker. If anything, it is the power amp which you should be worried about, due to the change in impedance Mohawk mentioned. However:

    If it is an 8 ohm cab, the speakers are probably 16 ohm (or 4 ohm). Either way, your power amp should have been able to handle it. I'd guess the speakers are 16 ohm, so you needed significantly more power to get a reasonable volume out of your 1 speaker set-up. Hence the amp clipping...
  5. If it was still working at the end of the gig, you didn't damage the amp. One speaker doing the work of 2 could cause damage to the remaining speaker if you pushed it too hard. but again, if it was working at the end of the night, its still ok.

    Most likely the speakers were in series, so leaving one disconnected cut the impedance in half. The same power going into the lower impedance=more current=more heat.

    With one less speaker you may have had to actually boost the power to move the same amount of air, without acoustic coupling of the extra driver. Further increasing the current and heat involved at the jack.

  6. Both the speakers were hooked up during the gig.
    I only disconnected them each to isolate where the
    problem was coming from.

    The back of the cabinet has a switch to choose Ohms.
    16 or 4. I've always left it in the 4 position.
  7. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    I'll bet that the switch is a series/parallel switch.

    Turn it to 16 and I bet no sound to speak of comes out. The speakers will be in series and with one of them fried chances are the other wont work worth a darn.

    When you switch it to 4 ohms you are in parallel. Each speaker is powered independently of the other.

    That means that you have been running your amp at 8 ohms. Safe territory.

    Looks like you have one speaker to replace.

    But I could be wrong.

    Let us know!


  8. Just ordered the PS10 replacement speaker at Carvin.com.
    I should hopefully have it by the end of the week.
  9. tadawson


    Aug 24, 2005
    Lewisville, TX
    And regarding the warm 1/4" jack, you just discovered why 1/4" jacks are not suitable for high powered applications! They just plain were never designed for it, and that is what happens (or worse - failure).

    Unless the dying speaker had a sagging voice coil and shorted out, thus lowering the cabinet impedance, you should have been pulling less power, not more, running a single. A lot of driver failures are due to overheating the coils, and they distort, and drag on the pole piece and rub though the insulation on the coil and short. As such, I suspect that the bad speaker may well have been causing the cab to draw MORE power, but that speaker was just dumping it as heat, not sound, and since you had to drive the cab harder to get more sound, your amp definitely got a workout! In the future, if you have a failure like this, leave the bad speaker disconnected (as long as the cab is parallel wired) - very little good can come from trying to drive power into dead equipment. Sounds like you got away with it this time, though . . . .

    - Tim
  10. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    People tend to underestimate what a 1/4" plug can handle.

    I have had 1/4" plugs warm up also but only when using a light guage speaker cable.

    I have yet to see the problem inherent in the actual plug while using a heavy guage speaker cable.


  11. tadawson


    Aug 24, 2005
    Lewisville, TX
    With 14 or 12 guage cable, in PA applications I have had more failures that I care to admit to. Went to speakon and never looked back. And yes, these were quality jacks - Switchcraft. The 1/4" design was just never intended to handle power, although it does, to a modest degree.

    - Tim
  12. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    Good for you.

    Click here.


  13. I might be being blonde but i dont see the point you are trying to get over, i'll agree with what your saying about 1/4" jacks tho, they were used for a long time before speakons and worked fine, my SVT and Firebass both use them and ive never had a problem :)
  14. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    500w is alot of power. And I'm pretty sure that's continous. (The 'Connector Choices' heading in the article.)

    Even if a rig goes to 2400w (like mine) who the heck is going to use that much power at a continuous level?

    Well, not me anyway. YMMV.

    I'll bet MOST of us run under 500w continuous therefore MOST of us have absolutely no problem with 1/4" connectors.


  15. The cable I was using is a George L's speaker cable with
    banana plug at the amp out, and 1/4" at the speaker in.
  16. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    Very good cable.

    Do you know what gauge?
  17. Nope. I just had a local shop tech make up a couple for me.
    I'm also using George L's to go from preamp to power amp,
    and wireless to tuner.
  18. tadawson


    Aug 24, 2005
    Lewisville, TX
    So what's your point? That you know that there is a better solution out there, but you choose not to use it? I don't get it . . . . . deliberately choosing the inferior device makes no sense to me, especially when the difference in cost for a cable is about $3 (Switchcraft 1/4" connector, $3.54/each. Speakon $4.73/each, source Mouser electronics . . . and these are the 40A constant/50A peak version, not the "stock" 25A connectors.)

    The other thing you don't consider is vibration - a lot of the failures I have seen is due to vibration on bass bins. Look at a 1/4" connector closely - most are press fit assembled - the pin in the center that connects the center terminal to the tip is simply pressed in place, and with the high currents and vibration, these DO back out and the connectors DO get intermittent . . . .

    Hey, use what you like, but why so adamant about defending a connector technology that is being misused in the first place? And also, if 1/4" is so great, why in the 25 years I have had involvement in the pro audio industry (and seen the rigs of a lot of the big players first hand) has absolutely NOBODY used them?

    - Tim
  19. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA


    For MOST applications 1/4" connectors are fine. Always have been. Always will be.

    Is speakon superior in it's connectivity security and power handling? Yes.

    Are they necessary in most applications? No.

    Will they go the way of the buffalo? I wouldn't count on it any time soon.

    Nobody should feel that they have inferior equipment if they don't have speakon connectors because IT'S NOT TRUE!

    It's all about application.

    For somethings it's best, for others it just doesn't matter.

    That all I was trying to say.



  20. Petebass


    Dec 22, 2002
    QLD Australia
    From a speaker design point of view, when one speaker stops working, the good speaker suddenly has an enclosure which is 2x larger than what it was designed for, assuming of course both speakers were originally sharing the one enclosure. Larger boxes can result in detioration in the speakers excursion characteristics, meaning it's much easier to drive the speaker to the limit's of it's suspension. The result can be anything from distortion to a blown speaker, depending on how much punishment you throw at it.

    If the speakers had their own seperate chambers within the cab, then no problem.

    The moral of the story is that is one speaker blows, by all means limp home on whatever is left working, but be cautious. The remaining speakers WILL be more delicate.