Only 3 speakers working in a SVT Classic 410 HLF

Discussion in 'Amps and Cabs [BG]' started by PJS782, May 20, 2017.


  1. PJS782

    PJS782

    Sep 7, 2015
    Our lead guitarist bought a used Classic 410, somehow, he blew one of the speakers. He wants me to use it tomorrow for a neighborhood jam. I would be running it through a Carvin BX 700. He says missing a speaker is no problem. I say it is simply because the impedance is out of whack. He disagrees. I have a 10" driver, but it's 8 ohm, he says that will work. I don't know but I don't want to blow my speaker, either. What can I tell this guy? Thanks in advance- this is an awesome and very helpful site even if I don't log in often.
     
  2. You risk all kinds of mayhem. Tell him no.
     
  3. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    No to the 8 ohm speaker, however, if the speaker is mounted but not hooked up, you could probably get away with using it.
     
    AlexanderB and TheRealKong like this.
  4. TheRealKong

    TheRealKong

    Mar 17, 2011
    Downunderwonder sayd it. Refuse to play with a 410" - cab with a blown speaker.

    I persume the cab to be 8 Ohm, so every speaker has 32 Ohm impedance and is wired in parallel. If you mount your 8 - Ohm - speaker, the overall impedance will be 4,57 ohm impedance, what is not bad. But persuming that the Carvin BX 700 has 700 Watts @ 4 =hm, the three original speakers will see 100 Watts each, while the 8 Ohm - speaker is about to see 400 Watts! I think that you simply will blow your own speaker in no time.

    If you play with the damadged speaker, using three speakers @ 32 Ohm each, the overall impedance will be about 10.6666 Ohms. This is not bad, too. Every speaker will see 233 Watts. Maybe the Thiele-Small - Parameters will be out of control, but I think this will mostly be about the sound.

    So the impedance of the cab won't hurt your amp, but have the self esteem to refuse playing over a damadged cab. Make the cheap f*ck of a geetar player get an original speaker at last! Think about you and your sound. Ask another bassplayer, if he is willing to give you a cab for this gig.

    The math is done with the Duncan speaker impedance calculator, available on www.duncanamps.com
     
  5. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    It's a 4 ohm cab.
     
    AlexanderB and TheRealKong like this.
  6. TheRealKong

    TheRealKong

    Mar 17, 2011
    @JimmyM: OK, didn't know that. So I have to do the math again.... ;)
     
    Pbassmanca likes this.
  7. TheRealKong

    TheRealKong

    Mar 17, 2011
    OK, so three speaker @ 16 Ohms equal 5,3 Ohms, this would be OK. But as I sayd before, refuse to use that cab, not before it is fixed.
     
  8. The Carvin is your amp? If so tell him he can pay for its repair once the magic blue smokes has escaped from it. BTW isn't such a cab wired series-parallel?
     
  9. Playing with one blown speaker throws the cab tuning out of whack as it blows in the wind directly out of phase, thereby putting undue stress on the remainder.

    If the remaining drivers are all 16 ohm for a nominal 4 ohm cab you could possibly get away with your 8 ohm but Sod's Law says you will blow your 8 ohm in half an hour. That's if it has some bass ability.

    So NO! Take your own rig and stand by for unTWEAKING settings if randoms get to play bass.
     
  10. BassmanPaul

    BassmanPaul Inactive

    The bottom line here is that putting a bass through the cabinet will like as not tear the three working drivers to pieces. The driver with the open voice coil will act as a passive radiator until it’s cone fails under the pressure of three working drivers and then the cabinet will be completely unloaded.

    Post edited.
     
    Last edited: May 21, 2017
  11. I used to have an Ampeg 410hlf, and i bought it used cheap because it had a blown speaker. The cab is a 4ohm cab. I removed the blown speaker, and the speaker itself was 4ohm. Either way, my singer, who is knowledgeable when it comes to electronics, rigged it up to run with the 3 speakers. When i removed the blown speaker, none of the other speakers worked, i guess that means they are wired in series? Anyway, i used it without incident until I ordered a replacement speaker.
     
    Pbassmanca likes this.
  12. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    Series/parallel, where each pair is wired in series to make two 8 ohm pairs, then the pairs are wired parallel to make the cab 4 ohms.
     
    Geri O and AlexanderB like this.
  13. I remember having one of mine apart years ago and it is indeed a combo of series and paralell wiring. But then I got to thinkin'...

    In the scheme you describe here, Jimmy, if one speaker in each series-wired pair went out, the other speaker in the series-wired paired wouldn't work. Maybe it's two speakers in paralell and the two paralell-wired pairs are in series. That could result in one blown and three working speakers. And still be a 4 ohm cabinet imedance. Assuming the drivers are 4 ohms each.
     
    JimmyM likes this.
  14. Robb Fesig

    Robb Fesig

    Mar 14, 2015
    Pennsylvania
    Sometimes a blown speaker will catch fire (happened to me a long time ago). I could go into details if you want, but suffice to say you shouldn't connect anything you care about to a cab with a blown speaker.
     
  15. Pbassmanca

    Pbassmanca In the pocket n' thumpy. So woody, so greasy...

    I live in the Shwa too. Represent bro!
     
    shwabilly likes this.
  16. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Yamaha, Ampeg, Line 6, EMG
    A possibility. I'm certainly not the final word on that. I just figured that's how they wired it because it's typically done that way.
     
  17. PJS782

    PJS782

    Sep 7, 2015
    Thanks to all who responded to this post. Not only do I feel heard, but received much needed ohm knowledge.

    I ended up using an older Carvin RL210T with my Carvin RL115 and the gig went over very well. When the guitarist pulled up he looking all concerned asking why I didn’t use his cab, I simply told him I’m not risking it. He kinda shook his head and went to set up. For me, I finally got a sound I’ve wanted for some time and was well received.

    This site is on it- you guys rule
     
    Downunderwonder likes this.
  18. Raf Seibert

    Raf Seibert

    Dec 16, 2013
    Texas
    I would suggest that if the guitarist wants the 410 used, that he be the one to use it.
     
  19. BassmanPaul

    BassmanPaul Inactive

    Except at home where we simply say “Yes Dear.” :D
     
  20. Most guitarists don't give two figs what the bass player has so long as it isn't louder than them. At least he cares. Still a dork.
     
  21. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

     
    May 15, 2022

Share This Page