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  • Tricky (?) Resistance Thoughts...

    Well, it's tricky for me anyhow. You see, I bought a Kicker Comp 10" Sub, and planned on only having one. So I bought the 4 ohm model to match my amp requirements. Well now I'm thinking a little more kick is in order, and want to get another sub, and keep them on the same channel(ie. not buying a new amp). Without a spec sheet (can't find one), my amp's sub channel simply states "4 Ohm Subwoofer". It can easily draw enough power for these 2 comps, but resisitance is confusing me. If I hook-up two 4 ohm subs in parallel, 2 ohms, so no good. If series, 8 ohms. First off, I'm assuming (as it seems to be the general case) that it can handle higher resistance, it's the lower resitances that cause instability issues. Is this flawed thinking? Will this work? Thanks in advance. Oh, and can you think of any problems running @ 8 ohms? I know it's high, but thanks for your ideas.
    My Carputer! (More Car Pics at the end)
    2 Kicker Comp 10"
    Epia M-9000, 256 MB DDR, 120 Gig HD
    Lilliput 7" VGA Touchscreen
    Check it out?!

  • #2
    I have no idea about amps but if you were to put them in series you would be splitting the voltage between the subs.

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    • #3
      I know, but in parallel, my amp wouldn't be stable (2 ohms)
      My Carputer! (More Car Pics at the end)
      2 Kicker Comp 10"
      Epia M-9000, 256 MB DDR, 120 Gig HD
      Lilliput 7" VGA Touchscreen
      Check it out?!

      Comment


      • #4
        some are 2 ohm stable
        My Mazda 3s

        My Mazda 3s on Car Domain

        [||||||||||||||||||--] (90%)

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        • #5
          I know LOL, but not mine! I don't want to invest in another amp.
          My Carputer! (More Car Pics at the end)
          2 Kicker Comp 10"
          Epia M-9000, 256 MB DDR, 120 Gig HD
          Lilliput 7" VGA Touchscreen
          Check it out?!

          Comment


          • #6
            you wouldn't happen to have amp brand/model would ya?
            My Mazda 3s

            My Mazda 3s on Car Domain

            [||||||||||||||||||--] (90%)

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            • #7
              Well it's a cheap amp that I can't find any specs on. This is all I can find. http://www.walmart.com/catalog/produ...A96481%3A39008

              Oh no! They sell it at walmart. Oh well, sounds great.
              My Carputer! (More Car Pics at the end)
              2 Kicker Comp 10"
              Epia M-9000, 256 MB DDR, 120 Gig HD
              Lilliput 7" VGA Touchscreen
              Check it out?!

              Comment


              • #8
                the sub is svc 4ohm or dvc 4ohm?
                rebuilding carpc... kinda..

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                • #9
                  Assuming Single voice coil
                  My Carputer! (More Car Pics at the end)
                  2 Kicker Comp 10"
                  Epia M-9000, 256 MB DDR, 120 Gig HD
                  Lilliput 7" VGA Touchscreen
                  Check it out?!

                  Comment


                  • #10
                    lol..is there room for 4 subs?
                    rebuilding carpc... kinda..

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                    • #11
                      hehe, cute.
                      My Carputer! (More Car Pics at the end)
                      2 Kicker Comp 10"
                      Epia M-9000, 256 MB DDR, 120 Gig HD
                      Lilliput 7" VGA Touchscreen
                      Check it out?!

                      Comment


                      • #12
                        So seriously, is there a resistor I can add? make my 4 ohm 8 ohms? I think a 125 watt 4 ohm resistor might be hard to come by.

                        edit::http://www.smr-archive.com/forum_2/messages/723.shtml

                        edit:: Ok Ok, I did a little searching (should've done earlier, my appologies) and found a few good topics @ the12volt.
                        Anyhow, my amp has a R/L input for the subs, that can only lead me to assume that it's rate 4 ohms x 2 channels.
                        My amp has three 30 amp fuses (front, rear, subs). 30x12 (AMPSxVOLTS)=360 watts MAX 360x.707 (Wattsx.707=RMS)=~255 watts. That is @ a 4 ohm load (the de-facto on the amp) by 2 channels. So divide that by 2 (remember, twice the resistance) 255/2=~127 watts x 2 channels. The RMS value on my subs is 125 watts... buy my amp only has one sub output (which is why I'm hooking up in series).

                        So can anyone verify my math, and also if my final wattage is for 2 channels. Or am I going to get 127 watts total/2 woofers? Thanks again!
                        My Carputer! (More Car Pics at the end)
                        2 Kicker Comp 10"
                        Epia M-9000, 256 MB DDR, 120 Gig HD
                        Lilliput 7" VGA Touchscreen
                        Check it out?!

                        Comment


                        • #13
                          impedance is not the same as resistance.. me thinks
                          '96 Chevy Cavalier - EPIA M10000, Win2K,MediaCar, Deluo GPS Mouse with Routis, 60GB external HD, 7" widescreen monitor from DigitalWW.

                          '00 Jeep Wrangler - planning stage


                          What can BROWN do for you?

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                          • #14
                            I can understand your questions and concerns... yes, to go up in impedence (basically resistance) in ohm rating reduces the demand on the amp... ohms law... if power output is kept constant, and reistance goes up, current output goes down... the problem is that if you do this, your not going to be able to move the subs as much... you MAY get slightly more output out, but at what cost? Another sub? Ok, so maybe you give it a shot and go parallel... drop your load to 2 ohm... but now you risk smoking your amp... most likely, if your amp says, "4 ohm subwoofer", it isn't gonna take a whole lot of beating at 2 ohms before it shoots craps.

                            Basically, an amp with TWO sub channel outputs can handle 2ohm per channel in stereo mode, but as soon as you bridge it, they become 4 ohm stable as the load is seen differently by the amp internally (if that makes any sense)... that is probably why your amps says "4ohm subwoofer"...

                            There are lots of options but adding a resistor to the speaker system to adjust the load is going to be a waste of time IMO. I think you'd be better off either getting rid of your one 10" sub and getting a 12" sub of the same line... increased cone surface area is going to give you an increase in output... affectively what you are trying to do by adding another 10" sub. Your other option is to ditch the amp and get something with a little more testicular fortitude...

                            Or, at your own risk, get the other 10" sub and give it a shot... keep the volume under control and if it has a separate gain control for the sub channel... turn it down a little and keep an eye on the temp of the amp. I've had a few rinky-dink amps go a long way with a little TLC.

                            Good luck!

                            Coach... aka Randy!
                            Coach... aka Randy! (I often forget who I really am!) ;)

                            ***Too many pieces and parts to list... maybe someday I'll show'm to ya!***

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                            • #15
                              Originally posted by b_nom
                              impedance is not the same as resistance.. me thinks
                              Resistance is basically just to a DC current... when you have a coil or inductor which is what a voice coil is... it will read a certain "resistance" with a VOM (volt ohm meter) but if you were to bench test it, it will have a different "resistance" depending on the frequency you feed it... a coil will resist an oposition in current change... therefore, the higher the frequency you input, the more resistance you will have... ok, probably too much information... I guess my point is... Yeah, what HE said up there!

                              Later!

                              Randy
                              Coach... aka Randy! (I often forget who I really am!) ;)

                              ***Too many pieces and parts to list... maybe someday I'll show'm to ya!***

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