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conflicting answers from tech support depts.

Discussion in 'Amps and Cabs [BG]' started by Josh Ryan, Sep 4, 2002.


  1. Mackie, and I'll tell you why

    6 vote(s)
    100.0%
  2. SWR, here is why

    0 vote(s)
    0.0%
  3. No one is right! this is why

    0 vote(s)
    0.0%
  1. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Staff Member Supporting Member

    Mar 24, 2001
    I have a Mackie 1400i power amp
    1400 watts @ 4 ohms bridged
    1000 watts @ 8 ohms bridged
    700 + 700 watts @ 2 ohms stereo
    500 + 500 watts @ 4 ohms stereo
    300 + 300 watts @ 8 ohms stereo
    and an SWR Workingman's 4x10
    400 Watts RMS 8 Ohms
    cab. Tired of contradictory info, I emailed both companies. I got different answers. I think Mackie is correct, based on what TB members have said, but I thought I'd ask about my gear very specifically in case I'm really just not getting something. (This can happen, see my milliamps thread in effects!) Thanks for taking the time to look this over.



    SWR said:
    Hello,


    Thank you for your interest in SWR products.

    [me]
    I have a Workingmans 4x10. I have no bass amp head, but have been using a mackie1400i power amp. I don't want to kill my 4x10, so I was wondering what mode should I run the Mackie in to preserve the speakers? [me]



    300 watts @ 8 ohms per side in stereo.

    Mackie said:
    Your best bet would be to run the amp in bridged mono mode. The amp will deliver 960W maximum to the speaker. This may sound like a lot of power, but you're better off having MORE power available & not using all of it than running with just enough or too little power. If you have extra power that you don't use, you will never clip the amp & blow the speaker. If you drive it too hard, of course, you can burn out the speaker, but if you respect this fact & don't push it too hard, you'll be better off.
     
  2. awesome

    awesome

    Aug 14, 2002
    Belgium
    Mackie is right cause it will get you the most power :D

    The cab should be able to take 1000w I guess.
    If I were you I would try with 300w and if you feel you haven't got enough power, run it at 1000w.

    just my 0.02€
     
  3. Mackie is right....it's not like the Mackie is putting 1000 watts continuous into that cab.....I bridge 1000 watts into my SWR 8x8 rated at 480 watts without any issues at all. That's just SWR rep doing a CYA (Cover your azz).
     
  4. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    ACtually, I think both Mackie and SWR are slightly wrong in a sense because neither troubles to find out *how loud you wanna play.* If you play duets with a jazz pianist in a restaurant, SWR's way is just fine. If you need somewhat more volume and specifically headroom, Mackie's way makes more sense. (But note the caveat that pushing the speaker too hard with a bigger amp, even without clipping, can burn it out. Clipping *in and of itself* doesn't kill speakers, nor does having a buttload of clean power available mean that you can't damage a speaker.) If you need killing volume, to the point where you're pushing the limits of the Mackie, your cab is in danger and you should get either one that can handle more power or a second one that can handle at least as much as the first.
     
  5. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Staff Member Supporting Member

    Mar 24, 2001

    So getting something that does 800 watts at 8 ohms (for example) and running the Mackie in mono at 960 watts at 8 ohms is best.
     
  6. just a quick comment (I'm on the road right now). Well put, Richard. That makes a load of sense. Josh, I think you'd be fairly safe running the Mackie in bridged mode with that cab as long as you are mindful of not running it real hard. If you have to hit the amp real hard you need another cab!
     
  7. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Staff Member Supporting Member

    Mar 24, 2001
    What is real hard? Would I be able to hear anything? Could I tell by the lights on the amp? Does it help if I leave the amps limiter on? I'm thinking about the SWR goliath3 4x10 8 ohms at 800 watts or the Bag End version (slightly used, if he ever actually sells it!) with the same rating. :confused: :confused:

    thanks for the input everyone.
     
  8. I push 2000 watts through 500 watt speaker in a PA system all the time. Its like a corvette. "It can also go slow" but the extra power is nice to have
     
  9. Ívar Þórólfsson

    Ívar Þórólfsson Mmmmmm... Supporting Member

    Apr 9, 2001
    Kopavogur, Iceland
    Blisshead: My guess is that you shouldn´t go much over 6-7 on the master volume. Stay within that and you should be safe.

    IMHO of course, If I´m wrong, someone please correct me then :)
     
  10. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    Well, best? I dunno: it depends on your application, as I said. (What kind of situations do you play in, BTW?) I mean, I personally would probably tend to err on the side of having more power handling in my speakers, but if you don't come close to using even half of the Mackie's power on a regular basis, then you should be fine with bridging it into what you have. If you wanna be really safe, get another cab.
     
  11. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Staff Member Supporting Member

    Mar 24, 2001
    The band I play in and the places I play call for pretty loud volume. I find myself pushing the Mackie at the 300 watt stereo setting. Mayne there will be a big difference set the other way though. I'll try it.
     
  12. Richard Lindsey

    Richard Lindsey

    Mar 25, 2000
    Metro NYC
    Cool, might as well try it.

    If you're "pretty loud," though, I'd consider adding a 2nd cab (yeah, easy for me to say when I'm talking about someone else's back). That way you can run 300 W into each (if you want to stay with the SWR way, that is), and you'll also gain acoustic output from the added speakers. You won't be able to bridge into two 4 ohms cabs with the Mackie, though.

    Another thing you could do is stay with one 4-10, but get one that's more efficient and handles more power. (What fun to spend other people's money;) ....)

    Good luck.
     
  13. hmmm.. i would say that they are BOTH right

    remember your question was:

    "what mode should I run the Mackie in to preserve the speakers"

    If i understand correctly, speakers are best preserved by not running excess current through the coils (it tends to melt them!) as well as by avoiding high powered VLF information (below 20 Hz) as it can cause physical damage from excessive cone travel.

    The real question** should be referred to SWR, or more likely, to whatever company actually manufactures their drivers.

    **That question would be "what is the maximum sustained RMS power rating - and what is the maximum INTERMITTENT RMS power rating, particularly, what is the specified "time before burnout" of the intermittent rating?"

    Armed with that information, you would have a better idea of how 'safe' it is to use some of that spare headroom.

    While "Clipping" does indeed hasten the failure of some drivers, its usually only because the clipped signal generates a lot of harmonics, and that extra high-frequency energy can quickly exceed the power rating of the driver...

    Incidentally, 'RMS power handling' is a SINE WAVE measurement, so clipping isnt a factor! If a driver is rated for 300 Watts RMS continous - and you try to drive it constantly with 350 watts pure sinewave, you are NOT going to "preserve the speakers"

    Ditto, if a driver is rated for 300 Watts RMS continous / or "Intermittent maximum rated" for "600 Watts RMS for 1 second" - and you try to drive it for just 1.5 seconds with 601 watts of pure sinewave, you are NOT going to "preserve the speakers" either....

    I think its wonderful to have lots of clean headroom, but clean power can melt yer drivers too, if there is enough of it!

    IMHO: The best way to preserve yer speakers is to over-rate them!

    If you need 120 dB SPL, and yer chosen speaker system(s) dispersion and efficiency indicates that you can provide this level of with ONE 400 Watt "powerhandling capacity" cabinet, driven at 300W RMS -

    Then by all means you should run a 600 Watt amplifier, to ensure yourself lots of headroom. A 600 watt amp limited to 300 watts shouldnt distort!

    But in that case, if you want headroom AND 'well-preserved speakers' you would be advised to run that 600Watt amp into TWO of those cabinets

    (adjusting accordingly for the effect of impedance - you just want 300 Watts in (and ultimately, 120dB SPL out!)

    Luckily, manufacturers are making higher and higher power handling drivers all the time, and "hard limiters" are available to make sure you never put too much current out!

    Incidentally, on the subject of "preserving speakers" - a cheap and dirty "hard limiter" is a fuse or circuit breaker of the appropriate rating, installed in the speaker cabinet :)
     
  14. Josh Ryan

    Josh Ryan - that dog won't hunt, Monsignor. Staff Member Supporting Member

    Mar 24, 2001
    Thanks! This will take me a bit to digest! I am going to forward your question on to the folks at SWR.
     
  15. ldiezman

    ldiezman

    Jul 11, 2001
    Nashville
    I myself run in bridged mode.....

    as long as you don't turn your power amp on full.. you will be fine..