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Loudspeakers Best way to power subs?

Discussion in 'Sound, Music, and Intercom' started by llewop, May 18, 2009.

  1. llewop

    llewop Member

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    I have two EV "Force" Subs rated 8 ohms and 300 watts.
    I tried powering them with Europower 2500 in two channel mode. I used a Y cable from a single input to both channel inputs. That should be around 480 watts per side.
    The results were dismal. No thump. No bone crushing lows like I expected. Should I bridge the amp and parallel the speakers? That amp is rated 2400 watts at 4 ohms in bridged mode. Is that to much power for the 300 watt subs. I really am trying to discover how to make these subs really bring something to the table. Should I invest in a crossover? I have an EQ with a subwoofer output with a high cut filter. Is that where my problem lies. I know the EP2500 is not the greatest amp but it should make these subs thump with some authority. Just trying to learn.
     
  2. KProductions

    KProductions Member

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    Hi,...

    an EQ with a sub output should suffice for your crossover (not as good as an actual crossover but probably not the reason your losing "thump". I am assuming you are using your eq correctly and have it in the chain so that the sub output is only sending to the sub amps (and not the tops as well).

    What are you using for tops (cabs and amps) and how much power are they getting....? A general rule I like to follow is to supply your subs with twice the power as the tops. If your tops far outpower your subs,... then the lows will not keep up with the highs.

    Also, - What is the size of your room and where/how are your speakers placed...?
     
  3. BillESC

    BillESC Well-Known Member Premium Member

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    You are very much underpowering the subs.

    From EV's web site:

    System Power Handling (continuous/program/peak) 350/700/1400 Watts

    2400w in bridged mode should give you what you're looking for. Just don't let anything clip.
     
  4. museav

    museav CBMod CB Mods Departed Member

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    There could be a number of issues involved. Just because an amplifier is rated X Watts does not mean it is providing X Watts, so one step may be whether you are actually making the most of what you have. Proper gain structure and signal levels are the trick there. But just as likely as power issues are factors such as the effects of the sub placement, the effects of the room, proper crosssover and EQ settings, and so on. These can all be factors regardless of the amplifier power. If you have problems due to room modes or boundary cancellation or less than optimal processing settings, more power may not do anything. Also, some of the "thump" many people expect is sometimes associated with the very low end of the mains rather than the subs, another reason why less than optimal crossover settings can be a problem.
     
  5. llewop

    llewop Member

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    :)I spent the afternoon experimenting. I placed the EP2500 in briged mode and adjusted all of the DIP switches for that kind of work. I parallelled the speakers and WOW the difference is astounding. I will need to adjust the SP2's to balance with the subs. The SP2's are 1200 watts per side. I think it sounds great. We will see I guess when next I require the system to perform.

    Thank you,
     
  6. waynehoskins

    waynehoskins Active Member

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    I presume the Behringer amplifier doesn't mind looking into a 4-ohm load when it's operating bridged?
     
  7. museav

    museav CBMod CB Mods Departed Member

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    I'm glad it apparently worked but the difference expressed indicates to me that something else was wrong, perhaps some of the other dip switch settings or some wiring. Based on the amp specs, and trying to tweak all the ratings to be for the same conditions and relevant to a subwoofer, what you should get from running in bridge mono versus two channel mode is simply about a 3.5dB increase in output, definitely noticeable but hardly "astounding".

    One thing to consider with paralleled speakers and bridge mono operation is that the 'nominal' impedance of a speaker is not the minimum impedance. The current EV Force 18" sub specs show a nominal impedance of 8 Ohms but states a minimum impedance of 6.8 Ohms, so the minimum load with two speakers in parallel is 3.4 Ohms, not 4 Ohms. In addition, the EP2500 is rated for 4 Ohm, bridge mono operation but only at 1kHz and 1% THD, not at 20-20kHz and 0.1% THD as for all the other mode and load combinations. So just keep in mind that the load and frequencies likely involved in this application may be stressing the amp a bit. You may be fine but I personally do not like running amps so close to their limits, especially less robust amps.
     

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