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Any plate amps stable at 2ohms?

Discussion in 'Home Theater Projects' started by Chris Brock, Jan 20, 2004.

  1. Chris Brock

    Chris Brock Second Unit

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    Does anyone know if any of the plate amps out on the market can handle a 2ohms load? And if so what ones? If I would need extra cooling that would be fine because I have access to tons of computer parts and can get some very nice cooling fans.
     
  2. Chris Brock

    Chris Brock Second Unit

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    ok i have done some research and it seems that I should be ok but I need to come up with a way to mount a cooling fan for that amp. So if I use say the PE 250 plate amp and mount it in its own small box with some 3" cooling fans should i be ok to run it at 2ohms?

    Also would anyone have an idea about how much power the PE amp would produce at 2ohms?
     
  3. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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    Not trying to go against your idea, but do you have to have a Plate amp? Thought about a pro-sound amp?

    Not sure how your setup looks (how you get 2 ohms: single 2 ohm coil driver, DVC 4 ohm, (2) 4 ohm drivers, etc.), but the QSC RMX850 can be found for only $269 with free shipping if it will work with your driver configuration.

    Specs:

    8 ohms EIA 1 kHz, 0.1% THD 200W
    4 ohms EIA 1 kHz, 0.1% THD 300W
    2 ohms EIA 1 kHz, 1% THD 430W
    BRIDGE MONO MODE
    8 ohms EIA 1 kHz, 0.1% THD 600W
    4 ohms EIA 1 kHz, 1% THD 830W
    Signal to Noise, 20 Hz-20 kHz 100 dB
    Distortion (SMPTE-IM) Less than 0.01%


    Brian
     
  4. Chris Brock

    Chris Brock Second Unit

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    that was actually my first thought, but this sub is actually for a friend who does not have very much money and really cannot spend more then about $150 for a sub amp. That amp would be prefect though[​IMG]
     
  5. Geoff L

    Geoff L Screenwriter

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    Where do you get information that the PE-250 will drive a 2-ohm load (with forced air extra cooling)??

    Very curious as it is not recommended by the manufacture and will void the warranty...

    Geoff

    Well after re-reading the post, it seems you say it's ok then ask if a couple 3" fans would cool it enough. A little confusing ...

    Everyhing is going to depend on what your driving (sealed, ported, pr, LT, etc and definitely how hard.. If the amp is not pushed hard etra cooling may work fine, but if the amp is going to be working hard at all you may have problems with shut down. Both from blown fuses or thermal (heat shut down)...
     
  6. Wayne Ernst

    Wayne Ernst Cinematographer

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    Brian,

    Can you point me to the vendor who offers it at this price with free shipping??

    Thanks!! [​IMG]
     
  7. Chris Brock

    Chris Brock Second Unit

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    here is what happend. i got the chance to talk to a friend in VA that owns one and runs the heck out of it. his is pushing a JL audio 12w6 car audio sub. it is dual 6ohm coils that he has wired in parallel so the amp sees a 3ohm final load. he says that the amp rarly if ever gets abnormally hot and he is using no additional cooling. So i was kinda specualting that droping the load to 2 would be ok but that i would defintly want to use a method of cooling to be safe.

    i am also interested to see where you can get a RMX850 shipped for 269? i might have to get one for myself!
     
  8. Geoff L

    Geoff L Screenwriter

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    Best of luck, if the PE-amp will see a true 2-ohm load and you need to run it at all hard, fans or not, I belive you'll have problems.

    I speculate this, as I also have run DVC 6-ohm coils wired P for a 3-ohm load. Two seperate sealed subs, both with it's own PE-amp.
    Actually the average load each amp saw was closer to 2.7-ohms.

    One of the sub amps would handle it better (both sub where identical), than the other. But, both amps would thermaly shut down when pushed. One amp would last a little longer, (5-min or so) at driving the load, than the other before shutting down. Even with a Big Box fan doing Mach-1 blowing on them, when pushed (not abused) they would still shut down.
    The extra cooling would buy you a few more minutes before this would happen tho...

    Granted they where sealed with no real internal heat disapation. Because I had a big EBS running also, I could let them play at a more relaxed output, this allowed them to run fine...

    I think the pro amp would be a much better idea if you need to stay with the 2-ohm driver choice. Really think you may have temp/shut down problems driving it with the PE-250, using fans or not!

    Maybe dry ice packs..[​IMG]

    Best of luck
    Geoff
     
  9. Brian-K-Owens

    Brian-K-Owens Stunt Coordinator

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  10. Wayne Ernst

    Wayne Ernst Cinematographer

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    Brian, Thanks!!! [​IMG] [​IMG]

    Awesome prices, too. Also, when you look below each item, you keep seeing *free delivery* which is also a nice touch. If anyone prefers to use this vendor, just sign up at their site and they will send you a price "key" which will tell you how much they will discount the item from the lowest listed price - (e.g. The MAP (Minimum Advertised Price is posted, but they also have two "stars" listed under the NSL price column) - you get to take an extra 20% off the lowest or MAP price that is listed.

    Best of all, the place is only 200 or so miles from me - which means somewhat-quick delivery if they use ground shipping!!
     
  11. Chris Brock

    Chris Brock Second Unit

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    thank you for that link!! that store is only about 1 hour from my house so i will probebly be visiting them somtime soon.

    as for the amp, i think you have convinced me. Now i need to talk my friend into uping his budget!
     
  12. Chris Brock

    Chris Brock Second Unit

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    ok i think i might have found a solution for my friends problem. How would a Crown XLS202 work for him? Since we have 2 4ohms coils i we could wire it in series and the amp woudl seea 8ohm load. that says says it will put out 400wrms at 8ohms mono which would be a perfect amount of power. does anyone see and issue with this?

    the Crown XLS 402 which is rated at 1180wrms @ 4ohms mono is only $263 shipped!
     
  13. Wayne Ernst

    Wayne Ernst Cinematographer

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    Chris,

    I've thought long and hard regarding the Crown XLS amps. In fact, I was at my local Guitar Center store last week where they carry both the QSC RMX series and the Crown XLS series. The QSC that I was looking at was $30 less than the Crown - and the salesperson told me - in his opinion - the QSC was a much better amp. The Crown "XLS" series is essential at the "bottom" of Crown's lineup.

    Since you need to drive an 8 Ohm load to one channel, I'd also consider the following: Nady Amp - 900 watts @ 8 Ohms for $179 - The shipping should be pretty cheap - $15.00 or so. However, the amp is heavy - 38 Lbs., I believe. [​IMG]
     
  14. Chris Brock

    Chris Brock Second Unit

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    that looks great!! I have not heard of Nady, do you have any opinions abotu there products? For that kind of price it is hard not to atleast give it a shot.
     
  15. Wayne Ernst

    Wayne Ernst Cinematographer

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    Chris,

    From what I've heard - and read, Nady seems quite good. Also, the amp being 38 Lbs. - vs. 25 Lbs. like the XLS-402 has to say something about it.

    Finally, the Nady features an "anti-thump" feature which should work out well for powering on a system without damaging the subwoofer driver. There was a Nady 900 that I was watching on Ebay - and the auction ended yesterday @ $127 + $30.00 shipping. It turned out to be a pretty good price, but I decided that I didn't care to get into a bidding war - because if I did, I'm sure the ending price would have been much higher - and more in the range that it's being sold for at Musician's Friend.

    Also, you might want to search this forum for "Nady" as we've covered it briefly in some of the other threads.
     
  16. Chris Brock

    Chris Brock Second Unit

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    Thanks alot to everyone for their help! This has been great. My buddy will be very happy with that Nady amp.


    now i have to think about if i want to purchase the 1100 nady amp[​IMG]
     
  17. Wayne Ernst

    Wayne Ernst Cinematographer

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    Me too. $249 + $16.00 (S&H) seems very tempting. The extra "headroom" would be nice - if everyone was out of the house and you wanted to turn things up a notch. [​IMG] [​IMG]
     
  18. Chris Brock

    Chris Brock Second Unit

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    actually if you look at the Nady SPA line the 1400 is only $279 and is rated for 1000wrms @8hms and 1400wrms @4ohms. man decisions decisions....................[​IMG]
     
  19. Chris Brock

    Chris Brock Second Unit

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    I actually just emailed a person who is selling a Nady SPA-1400 amp on ebay and specifically asked about the fan noise and general operating noise of the amp. ill let you know when i get a response.
     
  20. Wayne Ernst

    Wayne Ernst Cinematographer

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    Chris,

    Some observations between the SPA and XA series from Nady:

    XA - 2 cooling fans which are always on, but are variable speed.

    SPA - 1 cooling fan. Always on, but variable speed.

    Finally, the XA series weighs more than the SPA series. Granted, weight is not everything, but I wonder if the XA series is conservatively rated when it comes to its power output vs. the SPA series? Hmm ...
     

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