Lets talk Ohms...
Would someone be so generous and share your knowledge or a web link on how to match Speakers with Power Amps. The Ohms & \"bridged\" part have me confused... :roll: I recently bought a pair of JBL JRX112M 12\" but don't know what power amp to use to drive monitors to full capacity. Thanks in advance... 
Comments
Anyway, it's basically about impedance, wired parallel or series, that determines your final impedance. It's very important to get this right, or you'll roast your amp, and probably your drivers too, from clipping. o your homework, or it'll cost bux.
resistance = load (on electronics)
more load = less electricity through the speakers and visa versa
therefore, if you have the impedance of your speakers too low, too much current will flow and break your amp. If you exceed it, with solid state amps this is normally not a problem, but with tube, exact matching is necessary.
Bridged is when you have two speakers acting as a mono pair rather than a stereo pair.
If the Amp says use a 4 Ohm speaker, you need to use a 4 Ohm speaker
or two 8 Ohms in parallel ( = 4 ohms)
or four 16 Ohms in parallel (= 4 ohms)
If a Guitar Amp says 200 W RMS, you can use that to drive Speakers from 200 W RMS and upwards. Normally the guitar signal is driven to distortion levels for long time, so the speaker will be seeing close to the max Amp rating for prolonged periods.
If a household Amp say 200 W RMS, you can drive Speakers of 75 W and upwards. In normal music, there will be peaks of the full Amp power for only 1/100th of a second. The 75 W RMS continuous power speaker will normally handle 200W peaks of 1/100th of a second.
Ofcourse, there is a contrarian view that 200W RMS systems should be matched with 300W speakers. This gives more headroom.
and Headroom is king !!! If you have a 200 W RMS Amp, you could drive it at an average of 3-5 watts with 200W peaks at 0.01% distortion
or drive it to 20 W average with clipped ~220W peaks at 10% distortion.
If you really wanted 20W average but with unclipped peaks, you will need a system that can handle 500-600 Watts RMS
Heat dissipation is only one of the factors that limit the power handling capacity of a Speaker. Another important issue is travel of the cone. A 300W speaker will be designed to move more air than a 200W speaker and will handle transients and boosted bass better than a 200 W Speaker. I have seen speakers that dont burn off at high wattage, but reach the maximum cone excursion leading to the most horrible noise on earth. If I had used higher rated speakers with the same Amp, my sound would have been better.
The speaker is the weakest link in a PA / Household stereo system with the greatest limits on bandwidth, distortion etc. I would rather spend 75% of my budget on speakers and buy just about any branded Amp and CD player
However for Guitar, the tonal abberation of the Amp and Speakers is desirable and much sought after !!!
It depends.