Stupid question on RMS?

LILDRAGON
LILDRAGON Posts: 47
edited March 2004 in Car Audio & Electronics
Okay if my 6.5 speaker says recommended 60 watts RMS, does this mean that eack speaker is 30 watts RMS? Or does it mean 60 watts RMS to each speaker? Man hope this made sence...

Also what ever the answer might be, would 75 watts RMS be to much power per speaker? It is a Cadence ZX-651 Thanks again for all the help...
Post edited by LILDRAGON on

Comments

  • disneyjoe7
    disneyjoe7 Posts: 11,435
    edited March 2004
    It's 60watts RMS per speaker. Not 60watts RMS /2 = 30watts RMS. Also a 75 watt RMS amp shouldn't be over kill, I say that's fine.

    Speakers
    Carver Amazing Fronts
    CS400i Center
    RT800i's Rears
    Sub Paradigm Servo 15

    Electronics
    Conrad Johnson PV-5 pre-amp
    Parasound Halo A23
    Pioneer 84TXSi AVR
    Pioneer 79Avi DVD
    Sony CX400 CD changer
    Panasonic 42-PX60U Plasma
    WMC Win7 32bit HD DVR


  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited March 2004
    ya - 60 each ... also keep in mind... if you had a 150 watt amp that you really liked and wanted to use, you could always just turn the dial back on the gain and let it run at a lower power (say half or something close to that 60-ish range). so 75 certainly wont be a problem, and if by some freak of nature it is, just dial the gain back. note - all things being equal - having the gain at about half to 2/3 is "full power" out of the amp... if you dialed the gain all the way up to 100% you'd be clipping out the amp (again, under normal circumstances).

    happy listening.
    The Artist formerly known as PoweredByDodge
  • neomagus00
    neomagus00 Posts: 3,899
    edited March 2004
    why is it that turning the gain all the way up clips the signal? is it just a byproduct of the fact that the amp is trying to amplify a 5V signal as if it were .8V or whatever?
    It's not good, very fundamentally simply not good. - geolemon

    "Its not good enough until we have real-time fearmongering. I want my fear mongered as it happens." - Shizelbs
  • LILDRAGON
    LILDRAGON Posts: 47
    edited March 2004
    Hey thanks for the answer. I will be hooking up the amp this weekend. Hope I decide what deck to get before hand.
  • MacLeod
    MacLeod Posts: 14,358
    edited March 2004
    A speaker manufactuer will list the RMS rating not as a maximum but rather what they consider will give you the best sound quality with minimal strain on the speaker. So you could go well over 60 RMS and not blow the speaker its just that your SQ wouldnt improve and youd be putting a lot of burn on the speaker .

    The gain on the amp has one purpose; to match the amps input with the output of the head unit. In simpler terms, it determines how soon the amp will be at full power. Say your head units volume goes to 25 and your gain is set at about half. This means (assuming the gain has been set properly) that the amp will be at full power around 25. If you turn the gain all the way up then the amp will be at full power at about 7 or 10, so if you were to turn the volume up to 20 or so youd be pushing the amp well beyond its redline and it would start spittin' and sputterin'.
    polkaudio sound quality competitor since 2005
    MECA SQ Rookie of the Year 06 ~ MECA State Champ 06,07,08,11 ~ MECA World Finals 2nd place 06,07,08,09
    08 Car Audio Nationals 1st ~ 07 N Georgia Nationals 1st ~ 06 Carl Casper Nationals 1st ~ USACi 05 Southeast AutumnFest 1st

    polkaudio SR6500 --- polkaudio MM1040 x2 -- Pioneer P99 -- Rockford Fosgate P1000X5D
  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited March 2004
    your amplifier's power supply will give you two voltages ... that are equal, but opposite... for example... +10 and -10 volts DC.

    since AC bounces back and forth, a +10 / -10 voltage rail will give you 20 volts (if everything was absolutely perfect) peak to peak AC output at best.

    now lets say you turn yoru gain up so that the amp "wants" to put out a voltage of 25 volts peak to peak... this would require rails of +12.5 and minus 12.5 volts... but the amp only has + and minus 10... so what happens to the top of the wave?

    it gets "clipped" off... and the wave goes from smooth to flat (bad) back to smooth, and then flat again on th ebottom... like part of it was just cropped right off...
    The Artist formerly known as PoweredByDodge