Suggestions for amp/speakers

Discussion in 'Location Recording' started by stealthy, Nov 9, 2008.

  1. stealthy

    stealthy Guest

    Ive currently got a pair of Yamaha BR15's for mains, and a Crown XLS 202d amp. The speakers are rated at 200/400/800w, and the amp is rated at 330W/ch @ 2 ohms, 300W/ch @ 4 ohms, 200W/ch @ 8 ohms, 660W bridged mono @ 4 ohms, 600W bridged mono @ 8 ohms.

    Ive been running each speaker on its own channel on the amp. I'm assuming that each speaker is getting 200w. Correct? How can I push more power to them? Can I parallel them into one channel, and achieve 660w (330w to each speaker) in bridged mode instead of stereo? I know this will change from 8ohm to 4ohm.

    Im just learning about the ohm and wattage things, so this is kind of new to my understanding. I just want to know the best way to achieve the most reliable power. From my understanding, its bad on speakers to be under powered just as much as over powered, which is the current case, I believe.


    Soon I will be getting subs and monitors along with amps so I want to understand everything so I can piece together an effective setup. It seems, correct me if im wrong, that running in bridged mode for and setup (mains, monitors, subs) will net me more power, just at 4ohms rather than 8ohms/ch?)

    Thanks...
     
  2. Boswell

    Boswell Moderator Distinguished Member

    Careful here. The BR15s are rated at 200W rms, 8 Ohm. On paper, this is a good match for the 200W/chan output of the Crown amp, although there is a danger of driving the amp too hard, producing distortion that is rich in harmonics and overloading the tweeters.

    If you were to parallel the speakers as you suggest (to get 4 Ohm nominal) and run the amp as bridged mono (660W rating), you would have more headroom available before clipping for the same acoustic output power, which is probably a good idea. This may be the origin of your remark about not under-powering speakers.

    The danger area is where you attempt to translate that extra headroom into actual power by turning up the wick further. Basically, these budget speakers are not meant to handle much more power than you are currently supplying them with, and despite the in-built protection, you could very well end up with two smoking boxes after an hour or so's heavy use.
     
  3. Greener

    Greener Guest

    Plus, bridged would be mono.

    Yay.
     
  4. Kapt.Krunch

    Kapt.Krunch Well-Known Member

    Nuthin' wrong with that in most clubs. Very few people are in the sweet spot to take advantage of stereo, anyway. Also, the stage volume of the drums and amps usually blur the stereo spectrum....and their sound normally bounces around enough.

    You'd just end up with people on either side, in front of the PA speakers, not hearing what's coming from the other side, anyway, with a deliberate stereo spread in the PA.

    Kapt.Krunch
     
  5. Greener

    Greener Guest

    Aye, would never think of stereo for live. Not cruel like that.

    Just think that's an adequate home stereo. Never even thought of it being for a club.
     
  6. stealthy

    stealthy Guest

    Thanks for the info, but the BR15's are rated at 400w program, 800w peak.

    The BR12's are rated at 300w program, 600 peak.


    Correct me if I'm wrong, but it seems my understandings (as originally posted) seem to be correct, right?

    Thanks fellas
     
  7. Boswell

    Boswell Moderator Distinguished Member

    The BR15's continuous rating is 200W rms, the same as your amplifier output when driving two channels into 8 Ohms. The "program" rating is purely a marketing term and has no engineering meaning. The "peak" rating is a short-term power value to flag the difference between cone excursion and thermal capacity of the drive units, that is, they would take 800W in terms of the coil movement but would burn out it asked to do that for more than a few seconds.
     
  8. stealthy

    stealthy Guest

    Just a question, but is there a way to make an 8ohm speaker into 4ohm?
     
  9. Greener

    Greener Guest

    You can make 2*8ohm speakers into a 4ohm group by connecting them in parallel to the amp.

    Other than getting another 8ohm speaker, you could use a big resistor.. Why would you though?

    You can buy 4ohm speakers, they have meatier coils.
     
  10. stealthy

    stealthy Guest

    Ok thanks, thats what I assumed but just wanted to clarify.
     

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