Finally finished by Dual Tumult Infinte Baffle

Discussion in 'Home Theater Projects' started by Tom-K, Nov 19, 2003.

  1. Tom-K

    Tom-K Stunt Coordinator

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    As the title says, I finally finished by IB using (2) of the Tumult drivers. I previously had been using (2) Tempests. I am currently powering them with 1 channel of my Carver 753x. The manual states that it outputs 750 watts into 2ohms. Does this mean that each driver is seeing 750 watts? or is each driver seeing 375. These things seem to be working at about 25%. I thought IBs didn't require as much power to reach x-max. Don't get me wrong, these things sound awesome, but just seems like driving a Corvette at 40 mph when you know it can do so much more.
     
  2. Greg Yeatts

    Greg Yeatts Second Unit

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    Both voicecoils wired in series will give you about a 3.2 ohm load. Parallel wiring of two voicecoils for your amp is probably not a good idea. At 3.2 ohms its a good bet that your amp is not putting out 750 watts. Try wiring a Tumult to each channel.
     
  3. Rick Guynn

    Rick Guynn Second Unit

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    IB's don't require much power to reach X-Max compared to boxed or ported subs. The Tempest will reach Xmax with about 130 watts in an IB config. Go model the Tumult in LSPCad and see how much it's supposed to take to make it reach Xmax.

    I would think 375 watts would be more than enough to drive even a Tumult to its peak in an IB config.

    RG
     
  4. Denis P

    Denis P Extra

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    I assume your Carver is a Pro amp. If so, many actually deliver rated power into two ohms. Regarding reaching XMax; You can reach X Max at low power (maybe 50 watts +-) if you are at a low enough frequency, e.g. 15-20hz. If you run a simulation with some design software like lspcad, you will probably find that your IB is XMax limited at very low frequencies maybe up to 30hz and from there on up, big sub drivers can soak up lots of power before hitting XMax so you might still be power limited at higher frequencies. Of course, feeding 750 watts into your IB at 60 hz might very well make your ears bleed...
     
  5. Tom-K

    Tom-K Stunt Coordinator

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    Thanks for the quick reply, right now, each driver has the voicecoils in series, then each driver is in parallel for what I thought would be roughly a 2 ohm load. The drivers are clearly visisble (no grate yet)and they are hardly moving. Now with the same load, (vc in parallel and drivers in parallel, I thought that would also be a 2ohm load), the tempests were jumping all over the place.
     
  6. Brian Bunge

    Brian Bunge Producer

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    The Tumult has dual 2 ohm coils whereas the Tempests has dual 8 ohm coils. So wiring the Tumult VC's in series and then the drivers in parallel will give you a 2 ohm load. With the Tempests, wiring the VC's in parallel and the drivers in parallel gives you the same load: 2 ohms.
     
  7. Owen Bartley

    Owen Bartley Second Unit

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    I'm shocked that nobody has asked for pics yet! It sounds like quite a project, and I for one would love to see it.
     
  8. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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  9. Tom-K

    Tom-K Stunt Coordinator

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    Yes, I am talking about the 3 channel version of the 500x. I have two of them, so I had an extra channel, so I thought what the heck. Why not? I appreciate your knowledge on the amps, and it sounds like I need a pro-amp like a QSC. for this application. I know this might sound like foolishness, but I'm considering adding (2) more Tumults then getting the new parts express plate amp that puts out around 1000 watts at 4 ohms. Question though, If I wire all (4) drivers into a 4 ohm load, which I think should be able to be done, would that mean that each driver only would actually see 250 watts? This is where I truely get confused.
     
  10. RichardHOS

    RichardHOS Second Unit

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    Yes... after you have calculated the final load presented to the amplifier, you divide the amplifier's power output into that load by the number of drivers in the ciruit to get the power per driver... assuming you don't have any odd parallel/series combinations where some drivers get disproportionately more power than others in the same circuit.
     
  11. Puneet_Juneja

    Puneet_Juneja Auditioning

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    Buddy
    Enough of that technical stuff. Now u better post some pics of that monster[​IMG] [​IMG] [​IMG]
     
  12. Dennis XYZ

    Dennis XYZ Stunt Coordinator

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    Cool sub!

    Yeah, you need more power. The Tumult is an extremely inefficient driver. This is what I get from one of SL's spreadsheets to drive a single Tumult to Xmax with the voice coils in series. These are the 8 ohm power ratings of the amp. The impedance is high at these frequencies so voltage is the limiting factor and the 8 ohm rating is the one to use. For the two drivers, a stereo pro amp would be best. Get the biggest baddest one you can afford and run one driver off each channel. I'd consider the $600 QSC RMX 2450 (450 W/channel into 8 ohms) sort of a bare minimum.

    Freq8 ohm power rating
    10145
    11166
    12192
    13224
    15265
    16316
    18381
    20465
    22571
    24710
    27891
    301131
     
  13. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    You can get the QSC PLX3402 for under $1000, including shipping. At 4 ohms mono, it is around 3400 watts.

    Brian
     
  14. Rick Guynn

    Rick Guynn Second Unit

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    If you get one of those monster amps, you better make sure to put an appropriately-tuned rumble filter on it. Can you imagine what you might do to even a Tumult if you feed it 2-3x the Xmax power at 15-20Hz?

    RG
     
  15. Eric Eash

    Eric Eash Second Unit

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    i can't wait to see pics, come on, post them already. also, i need a rumble filter too, where should we look for one?

    eric
     
  16. Rick Guynn

    Rick Guynn Second Unit

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    There are a number of things that can be done for a rumble filter. Many plate amps have them built in to one degree or another. You could get a cheap single-channel parametric eq and us a low-end shelf filter as a rumble filter. I haven't had need of an external one as my amp has one built in, so I can't offer any part names, but I'm sure there's something out there...

    RG
     
  17. Denis P

    Denis P Extra

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    I've got a Crown XLS602 for $299 (including shipping at ZZounds when they were clearing out stock before bringing out the new "a" models) that puts out 1800 watts into 4 ohms bridged and it has a (defeatable)15hz rumble filter built in. I'm using it with my four AV15 IB for at least some protection against very low frequency, high power audio bottoming out my drivers.
     

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