Audio Systems: sub amp matching, watts rms, rms power


Question
QUESTION: i have a 2 sub 4ohm box and the subs put out 1100 a piece. with 600 rms total. if i hook up 2 amps, what should each amp be putting out in rms?

ANSWER: First, rms power is a misnomer. I know everyone uses it, but the correct term is continuous or average power. Ignore the peak power rating figure as they don't have any meaning in terms of audio power to a speaker.

The amplifier power rating is given for the impedance specified.  So, you must go back to the spec sheet (you didn't give me a model number so I cannot look it up) and find out what load impedance is specified for the 600 watts out.  Then, if the speaker load is at the specified impedance you may get the full 600 watts out.

But, give me the full specifications of the speakers and amplifiers if you want a complete answer; I will calculate it for you.  Or, give me the make and model number of each  product so  I can look them up.

Finally, don't be so power concentrated.   It is not power so much as proper matching of components and acoustic loading that is important in a system.  Further, a few watts one way or another is not so audible.

Lastly, you mentioned a 4 ohm box; a box does not have impedance; the speaker driver is the load impedance to the amplifier.  So you must know what load you are placing on the amplifier in order to determine the power transfer.   If the speaker systems load down the amplifier lower than it is specified for you can endanger it and cause it to burn out prematurely.

C



---------- FOLLOW-UP ----------

QUESTION: SUB- Capable of handling 1100 watts peak power; 600 watts RMS power
12" Low-Q optimized polypropylene drivers; mirrored dual chamber design
45 ounce strontium ferrite magnet
Built-in crossover
illumiNite cool blue illumination
Carpeted enclosure with Plexiglas viewing windows
Frequency response: 25Hz - 2kHz
Sensitivity: 89 dB
Impedance: 4 ohms

AMP- 4-channel power car amplifier
70 watts RMS x 4 at 4 ohms (100 watts RMS x 4 at 2 ohms)
200 watts RMS x 2 bridged output at 4 ohms (4-ohm stable in bridged mode)
2-, 3-, or 4-channel output
Variable high-pass/low-pass filters (50-400 Hz, 12 dB/octave)
Tuned Bass EQ (12 dB bass boost at 50 Hz for channels 3 & 4)
Subsonic filter (15 Hz, 24 dB/octave for channels 3 & 4)
MOSFET power supply
CEA-2006 compliant
STAR Topology (minimizes internal noise and prevents ground interference)
Speaker- and preamp-level inputs
Preamp outputs
Gold-plated screw terminals
Fuse rating: 25A x 2
8-gauge power and ground leads recommended - wiring and hardware not included with amplifier
13-1/4"W x 2-3/8"H x 9-

ANSWER: You have a 4 ohm system, meaning the amps are speced for 4 ohm loads and the speakers are 4 ohms.  So, you can wire them up any way you want so long as the impedance load on an amp does not go below 4 ohms.

Good Luck,

PS:  The only meaningful and useful specification on loudspeakers is impedance and dimensions (so it will fit in the space).  All other specifications are tainted badly with market hype and non-standard ways of performing the testing, so don't get too excited if they do or don't handle the power they are rated for.  


---------- FOLLOW-UP ----------

QUESTION: so will the amp i have work consistantly?

Answer
If you connect it as I have outlined it will be just fine.  But, you will have to decide how you are going to drive the speakers in order to  keep the load impedance above the 4 ohms that your amp requires.

The specs you sent do not give enough detail for me to know what these products are.  If you send me the make and model I can look them up and give you an answer relating to them.  For example, it is not clear to me if the speakers are a speaker system or a driver and if they are single coil or dual coil and how they are connected internally (if it is a self-contained box).