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| By: swez on Fri, 3 Oct 00:41:11 -0500
| | I see your point and have taken the same approach. I now have a USX-4065 and a JBL 2 channel that develops 300 RMS when bridged MONO to a 4 ohm load. (2 x 20A., fuses here) My goal is above average SQ and some degree of SPL. My target is a clean, pure, realistic mix of SQ and ~120dB of clean SPL. Plenty for me.
The JBL MONOVALVE series is 1 or 2 ohm stable. There is no power output differential between 1 or 2 ohms... just capability. Its Class D mode operation nets very efficient use of power VS power to drive the subs. Last time I calculated that, was very close top 90% efficient. Ie: 100 watts consumed, nets almost 90 watts output. The only drawback, class D will not do well above 500 Hz. Not bad huh?
Compare that to a classic 2/4 channel Class A/B amp. These are cleaner and more suited for high frequency reproduction. The are not as efficient as Class D models, but do the mid/highs well. The efficiency rating of most typical Class A/B amps is/are between 50-60%. That's not a big problem in modest 2/4 channel amps as far as power consumption goes... only when using larger 2 channel amps for subs, does the power efficiency come into the game. (500 RMS and higher)
NOTE: Amp efficiencies vary from one maker to another. Different designs and component choices play a part in this. Some amps just loaf along very nicely at rated power and stay cool. Some amps really puff hard at rated output and may generate a fair amount of heat. Indication of how close to the limits the amp design is to internal components. A cooler running amp is working less hard and will usually last longer than a hot running amp. ELECTRONIC DEVICE HATE HEAT !!!
The last major aspect to the system are the speakers. This is the soul of any good system. Here, the old addage... ya get what ya paid for is generally most notable. Efficiency ratings on drivers can be very deceptive by design. Some speakers tout a 92% efficiency rating, while others may be in the low 80's. Which is better? Without a frequency plot at 1 watt/1 meter over a wide range of usable frequencies, the numbers are meaningless, if not outright deceptive.
Better speaker makers have these LEAP plots on their web sites. The ones who don't want you to know them, do not. There's usually a good reason not as well.
Swez
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