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Discussion Starter #1
i have an amp that is 50 watts RMS @ 4ohm
70 watts RMS @ 2ohms

my speakers are rated at 55 Watts RMS @ 4ohms

i would like to make my amp throw out the 70w instead of 50w
so i need to put a another set of speakers ( parallel) convert into 2 ohm Which I DONT WANT TO DO. i have no space for more speakers but do want the extra juice.

My question is , Is there a reistor of some kind that i can put into between the + and - terminals on each output in addition to my speakers that will give me a 2 ohm resistance?

i was thinking of going into radioshack and seeing if they have a resistor of some kind to simulate the extra speaker.

any info is appreciated.
 

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Well it wouldn't be a resistor you'd want to get. If you put a 2ohm resistor on a 4ohm speaker, it would increase the resistance to 6ohms. If anything, you want the amp to see less of a load or less resistance. Less resistance equates to more power from your amplifier. However, I'm not aware of anything that can "reduce" the amount of resistance in a voice coil. :dunno:
 

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Well for starts a 4 ohm and a 2 ohm load paralleled will cause a lower load then 4 ohms and a 4 ohm and 2 ohm load series would cause a higher load then 4 ohms but not 6 ohms.


Anyway they do make a device (although rather pricey) that can convert the load seen by the amplifier and therefor deliver more power to the speaker. However this seems rather stupid considering your speakers are only rated 55rms and you're giving them 50rms already. The difference made by the extra 20rms per side is going to equate to MAYBE 2 or 3 db's extra volume. It's rather pointless not to mention the fact that you would be overpowering your speakers.
 

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Discussion Starter #4
Craig King said:
Well it wouldn't be a resistor you'd want to get. If you put a 2ohm resistor on a 4ohm speaker, it would increase the resistance to 6ohms. If anything, you want the amp to see less of a load or less resistance. Less resistance equates to more power from your amplifier. However, I'm not aware of anything that can "reduce" the amount of resistance in a voice coil. :dunno:
if in parralle 4ohm + 4ohm = 2 ohm

if in series 4ohm + 4ohm = 8 ohm
 

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Discussion Starter #5
#1SomeGuy said:
Well for starts a 4 ohm and a 2 ohm load paralleled will cause a lower load then 4 ohms and a 4 ohm and 2 ohm load series would cause a higher load then 4 ohms but not 6 ohms.


Anyway they do make a device (although rather pricey) that can convert the load seen by the amplifier and therefor deliver more power to the speaker. However this seems rather stupid considering your speakers are only rated 55rms and you're giving them 50rms already. The difference made by the extra 20rms per side is going to equate to MAYBE 2 or 3 db's extra volume. It's rather pointless not to mention the fact that you would be overpowering your speakers.

i see, i was not aware it would only be 2 o3 DB difference.
if thats the case your right. i was thinking of something like this
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2577263066&category=4664&rd=1
 

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Woops yah with the series it doesn't change but with the parallel it does. To decrease your load you'd have to parallel something with your sub anyway. I'd still not bother, it's not worth it!
 

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Discussion Starter #8
well it chances in both series or paralle, its just a matter of which way you want to go. as far as not worth it, i think you maybe right since its only 5 watt difference in power.

however adding a nother set of speakers parrallel would be nice, since i would get more juice but that power would be split in two. so i was hoping the ebay resistors might work.

anyhow its just a thought.
 
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Whoa whoa whoa...

No, a resistor is NOT the answer.

If you were to put a 4 ohm resistor in parallel with your 4 ohm speaker, you would, in theory generate a 2 ohm load, and cause your amplifier to put out the 70W RMS.

But take a look at where the power would be going...

As is, you have 1 amp, which will output 50W RMS into a single 4 ohm load. You have 1 sub, which presents a 4 ohm load. No problem, you get 50W RMS. (Ignore the power rating on the sub, as power handling is mostly a function of the enclosure anyway, and that's a completely different subject)

If you put a 4 ohm resistor in parallel, then the amp is presented with a 2 ohm load. It's capable of generating 70W RMS into a 2 ohm load, and, so it starts cranking out the extra power. Where does the power go? If we assume that the resistance is exactly equal (We can't really, but for argument's sake) then 1/2 the power (35W RMS) goes to the speaker, and is used to generate sound. The other 1/2 goes through the resistor, and generates heat and no sound.

The end result is that you've increased the load on your amplifier, making it work harder, and drawing more current from your electrical system for a net decrease in sound output from 50W RMS to 35W RMS. You've also introduced a source of distortion because the actual resistance of the subwoofer varies with the frequency of the signal, where the resistor value does not vary at all. It's a lose-lose situation.

So, to answer your question: Yes. It can be done, but No. You don't want to.

If you're really determined to try, though, make sure that you get a resistor that can handle up to 100W as the peak power is going to be much higher than the RMS. Also make sure that the resistor body is mounted well away from anything that shouldn't get really hot, because it will get hot. You're probably looking for a 4 ohm ceramic resistor, and you'll propbably want a heat sink, too.
 

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Discussion Starter #10
Beautiful, thats what i was looking for.

thanks , for the help Dan.
 
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