Questioni have a audiobahn aw121t 12 inch sub in a ported box 550 watts and 550 rms max i believe and 2 12 inch subs in a ported box all they say is 550 max watts a piece and they say dual on back thats it watt size amp do i need to get atleast 80% of the power out of them
AnswerHey Richard,
You will not get any 'power' out of the speakers (only audio output based on the speaker, the enclosure and the power applied by the amp).
It would be hard to say what 80% of an 'unknown' is.
As to the main question I could sum this up very easily if you had sent me the make/model numbers. Since you have not, this will be a basic lesson in impedance and amplifier loading.
If the specs are accurate and if you use Ohms Law, you would multiply 550 times .707 to get the RMS rating or '388 watts RMS' per speaker.
RMS power is average or continuous power. Never ever use peak ratings and you would be well-advised to avoid most manufacturers that do use Peak ratings.
So in theory, an amp with 700 watts RMS would suffice since you have two speakers.
Theory? Read onward my audio enthusiast.
Are these two speakers wired in Parallel or Series (or are they stereo pairs having a +/- lead for each speaker)?
Another important issue is what impedance those speakers are rated at (individually or per voice coil if they are a dual V/C design).
Basic example: If the speakers are 8 ohms each and wired together in Parallel (for mono) your amp will see a 4 ohm load. If they are wired together in Series the amp would see 16 ohms.
If they are 4 ohms each, the parallel/series sums would be 2 or 8 ohms.
This VERY important since amplifier RMS power is rated at a given impedance load.
For instance, most amplifiers will double (or half) their output based simply on the impedance load. An amp rated at 700 watts RMS at 4 ohms may only put out 350 into 8 ohms. Likewise (and only if it is designed to so do), that same amp may be capable of 1400 watts into 2 Ohms or even 2800 into 1 Ohm.
***IF you hook up an amp with a minimum rating of 4 ohms to a 2 ohm load.. you will fry the amp in little time.
If you are not sure, you should get an Ohmmeter and (using resistance 1x setting) plug it in to the speaker input terminals and see what it reads. Even though not exact, the DC resistance reading will give you a decent idea of the speaker impedance load as it is currently wired (stereo or not). Impedance is an AC reading and resistance will be a DC reading and therefore do not equal one another.
If you can locate the make/model numbers, let me know :)
Hope this helps out.
Jm
