Huge Problem

Discussion in 'OT Technology' started by speedricer, Jan 16, 2004.

  1. speedricer

    speedricer Go SpeedRicer Gooooo

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    Ok I have 2 15" xtant a1544's
    Ok I have them hooked to a ultra linear UL400HC.
    I have it running at 1ohm. at 1 ohm it puts out 1200 watts RMS
    Now the problem is My subs are only rated at 500watts RMS.
    Will I be ok as long as I don't crank on it? or if I keep the gain turned down? will I be ok?
    I mean with this setup it blurres my vision. I have the 2 15's in 6cu. ft. of space with two vents that are 2"x12" that is 14" long. And the bass is increadible deep and loud. But I"m just worried about blowing my subs.
    What do you think?

    casey
     
    Last edited: Jan 16, 2004
  2. speedricer

    speedricer Go SpeedRicer Gooooo

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    Oh and I've listened to it for probably like an hour with the gain turned up pretty high. but all day yesturday I listened to it with the gain about 1/4 way up. When i turned it about 3/4 of the way up it sounds alot better. Just worried about burning up the voice coils.
     
  3. 04

    04 Guest

    Huge problem? :confused:

    I don't see anything wrong with your situation. 100 watts more in the grand scheme of things isn't very much more.

    The thing to realize with speakers is that the power ratings are only a very rough guideline usually, and sometimes they don't even make any sense and are extremely overinflated. A good way of determining if you are playing your system too loud is if you open say your trunk with the speakers playing at their max volume and you hear funny noises, or it just doesnt sound the same as when played at lower volumes. Typically at that point, you have either gone beyond your speakers or amplifiers linear output capabilities.
     
  4. speedricer

    speedricer Go SpeedRicer Gooooo

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    ok actually it's 700 watts over.. :)
    it's 500watts rms for both subs together.
    and the subs are where the back seat used to be. And they sound very clear and full and these subs with this setup are just amazing. I have a friend who has 4 15" JL audio w0's and my 2 15's would blow his out the freakn water. I'm just worried because I've got like 350watts rms over the rating on each sub. But it sounds very good.
    You think I'll be ok?
    I know if it starts to distort or make noises to turn it down a lil. And beleive me i'm trying to be as carefull as I can.
    Oh and before I baught this amp I hadn't ever heard of them. I'm just wondering what you think about these amps?
    But thanks

    casey
     
  5. spicaly

    spicaly Active Member

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    the amps are probably overated as far as outage output
     
  6. speedricer

    speedricer Go SpeedRicer Gooooo

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    It seems to sound pretty good.
    just worried about my subs.. :)
     
  7. Scott P

    Scott P I are lurking through. . .

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    as far as I can tell by what you have said here you shouldn't have a problem. Logic says that since you are only provinding the 2 Dual 4ohm subs with a 1 ohm load, while giving it more that nearly 900watts more than rms rating (this according to manufacturers specs for the amp and the subs that you listed) the over powering of the subs in a sense compensates for the lessened strain of the load. I still wouldn't crank it to full volume with the gain jacked all the way up, but for normal usage you ought to be alright.
     
  8. GlocksRock

    GlocksRock Glock > You

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    Just watch your gains and you should be ok.
     
  9. speedricer

    speedricer Go SpeedRicer Gooooo

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    All I know is it sounds really good. With these 15's the bass is unbalievable (sp) deep.
    It also plays rock pretty good too. I thought with the size of the box and it being vented that it wouldn't play rock to well but it does. I'm pretty happy with the setup.
    But agian. thanks alot guys

    casey
     
  10. 04

    04 Guest

    Huh? :confused:
     
  11. Scott P

    Scott P I are lurking through. . .

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    Granted I am going on what was taught to me, but given that the subs are running at only a quarter of the potential effeciancy (i.e. getting 1 ohm resistance while beinge rated for a 4 ohm resistance); the lack of efficiancy is offset to a degree by the overpowering (in wattage). By far not the optimal setup for the subs, but not highly detrimental either
     
  12. GlocksRock

    GlocksRock Glock > You

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    correct me if I'm wrong, but doesn't the amp see the resistance, not the speakers. It is my understanding that the speakers present the load on the amp.
     
  13. 04

    04 Guest

    No, that has nothing to do with the output of the system.

    Lets say you have 4 of those woofers with dual 4ohm coils and you wire them all in parallel. That is a .5 ohm load. If your amplifier can drive such a low impedence (and lets say the amp puts out 1000 watts into .5 ohms), it will be exactly as loud as if you wired all of the voice coils in series (which would be a 32 ohm load) and put them on a 1000 watt amp that put out max power into 32 ohms.

    4 woofers act the exact same way on a 1000 watt amp as 1 would act on a 250 watt amp. In either case, the efficiency is the same for EACH woofer, but with each doubling of cone radiating area (like doubling the number of woofers) gives you an increase of 3dB of efficiency, or for example 96dB for 4 woofers with one watt compared to 90dB for 1 woofer with 1 watt.

    My guess is that you are confusing sensitivity with efficiency. Sensitivity is the amount of output with a given input voltage, while efficiency is the amount of output with a given input power (or wattage). For example, a 1ohm speaker rated to be 90dB with 1w of power efficient, will have a sensitivity of 99dB with 2.83v of voltage. The reason we use 2.83v when determining sensitivity is because 2.83 volts into 8ohms is equal to 1 watt, so you can reference it to a 8ohm speaker.
     
  14. 04

    04 Guest

    That is correct. It really doesnt matter how you wire the speakers, they will have the same acoustical efficiency as long as they are given the same amount of power.
     
  15. Scott P

    Scott P I are lurking through. . .

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    i see i was wrong. it doesn't really surprise me given how much i was originally taught has been shown to be wrong (what's scary is the fact that the installer that taught me most of the stuff i originally learned, and had to subsequently unlearn, was actually MECP certified). thanks for explaining it all to me though it makes a little more sense since the explination i had given didn't quite sit well with me
     
  16. 04

    04 Guest

    Well the problem with the MECP test is that it does not cover stuff like this. It only covers audio installation. FWIW, you really don't need to know that in order to install audio equipment in a car, or even ohms law for that matter, because it tells you how to wire up everything in the manual.
     
  17. speedricer

    speedricer Go SpeedRicer Gooooo

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    My amp is stable down to 1/2 and ohm. But it doesn't tell the power output for .5 ohms?
    at 1 ohm it is 1200watts rms
     
  18. theoretically, it would be 2400 watts. 1/2 the load = 2x the power. therefore, your amp would put out 600 @ 2 ohms, and 300 @ 4 ohms. i dont think that all amps can truly double their power though.
     
  19. midnite

    midnite OT Supporter

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    It doesnt always seem that way though, at least on some amps ive seen.
     
  20. 04

    04 Guest

    Ideally that would happen, but every time you halve your impedence, you increase current draw which consequently also causes a voltage drop.
     
  21. that's why i started out with 'theoretically'. i just didn't know exactly why you dont see a true doubling of power by splitting the impedence in half. voltage drop is a good explanation though.
     
  22. speedricer

    speedricer Go SpeedRicer Gooooo

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    From what I know.
    It is supposed to put out 500watts RMS @ 4ohms 800watts RMS @ 2OHMS and 1200watts RMS @ 1 OHM
    Oh it's also a mono high current amp.
     

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