Ok, my friend was talkn to me and said that the amp determins the ohms. Like if you have a 4 ohm sub and hook it up to an amp..say a 2 channel amp and you bridge it you will be running 2 ohms and that can blow up the sub, even if the wattage in within the range of the speaker....is this true. I always thought that the speaker and how you wired it up(such as in series and parrallel) determined what ohm load you where pulling...??? I have an infinity reference 12" sub 300 RMS 4 ohm can i get the Alpine MRD-M300 amp, here are the specs....will i be getting 300 RMS?
And is it all right to run the sub bridged so i get that 300 rms?
150 watts RMS x 1 at 4 ohms
300 watts RMS x 1 at 2 ohms
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Variable subsonic filter (15-50 Hz in 5 Hz steps)
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Top-mounted digital control center with cover
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ya its all in the speakers and how you wire them.

Brian

 

If its one 4 ohm speaker. And its not Dual Voice coil.
You will get 4 Ohms no matter whut with one Single Voice coil 4 ohm sub.
You will be giving that sub 150rms..
Speakers give the resistance not the amp. The amp isn't the load, the speakers are.

On a side note: Dont listen to ur friend he doesn't know wtf he is talking about.

 

Well the right answer is that the speaker will always be the same impedance, ALWAYS. BUT, if you drive it with a bridged amp, the amp will "see" half the resistance at each channel. It works like this, if you take a 4-ohm speaker and drive it with a bridged amp the amp will “see” a 2-ohm load on each channel. Now to complicate things. If you take two 4-ohm subs (or a dual voice coil sub with an impedance of 4-ohms per coil) and run them in parallel the speaker load is 2-ohms. If you drive that with a bridged amp each channel of the amp will “see” half of that, or 1-ohm per channel. In this setup if the amp is only 2-ohm stable you run the risk of killing the amp, NOT the speaker. And THAT’S the answer! Got it? Any questions?