hifonics zeus 2550 vs cresendo bc2000

[Ace87]

I had no idea jbl made an amp almost the size of a car door. I thought the original guy was talking about typical jbls that I see that put out maybe 1/8 of that power. I've never seen a jbl that put out over 800-1,000rms in person. I guess I've been living under a rock.. also I understand pretty much everything you said, but when u got to the semiconductor part at the end, you lost me..

I'm implying that you running .6 ohm nominal load does not necessarily mean that your amp can safely drive .5 ohm. It may or may not, but I can assure you that you're not seeing anything close to the advertised 95% efficiency ever outside of very controlled variables on a test bench and driving low impedance is very bad for semiconductors whether or not your amp is "built for it".
The "same old" Brutus amp that is very popular is popular because it's a proven design that's reasonably reliable and performs well at its price point. No idea about what you have, and I really don't care since I'd never run later than GenX hifonics. They've put their name on too much junk and I wouldn't want to be the guy playing Russian roulette with my money figuring out which are the good ones.

This will output at just shy of 200V, making up to 7500W at 4 ohm and .018% THD.

Most serious SQ amps will not drive .5 ohm or even 1 ohm. The flagship Zapco, Audison, and even JL are designed to operate at high voltage as are a number of the Brazilian big competition tier amps. Even Alpine and Kicker mono blocks make max power at 2 ohm.

The fact is, even if you design an amp to not protect at low impedance or to "handle" .5 ohm it's never good for semiconductors and very inefficient compared to running higher loads.

 

[hispls 5,000+ posts]

I had no idea jbl made an amp almost the size of a car door. I thought the original guy was talking about typical jbls that I see that put out maybe 1/8 of that power. I've never seen a jbl that put out over 800-1,000rms in person. I guess I've been living under a rock.. also I understand pretty much everything you said, but when u got to the semiconductor part at the end, you lost me..

Actually even the small JBL amps are pretty good, though they have made only a few larger than 1200W. Overall JBL/Infinity/Harmon products are very good. Their amps (most of which are small these days) are reliable, good quality, and do what they claim. They have made some highly regarded component speakers and subwoofers, and they have a very popular digital sound processor in their MS-8 which is rather well thought of around audio circles. JBL makes some solid pro audio as well (stadium and stage type amps).

In any event, in layman's terms, semiconductors are what make the power in your amp and are what typically let out the angry smoke when something goes wrong. Current = heat, and high current = high heat. Heat is the enemy of efficiency (again, these 90%+ numbers quoted by manufacturers are at some optimum frequency, typically 4 ohm impedance, and at just a hair under clipping power) and heat is what makes these components fail.

Running low impedance is dangerous. Perhaps you could liken it to running very high RPM in a car. Many cars can do it for a little bit. A great race car can probably do it more often and longer without trouble, but it's always very hard on things and unless you have some extreme-duty needs (your racing..... or dB-Drag racing in our case) you really should stay away from running things really hard. If you think 300$ is a lot of money to drop on car audio, you are in no position to try to be replacing things that you break trying to constantly red-line your equipment.

Yes, I did say that your amp probably never actually sees .6 ohm (your nominal impedance) but still you don't know unless you have some test equipment and have done some testing, and trying to go lower and lower if your only goal is daily music is really just not a great idea .

All that said, why upgrade your amp at all if you like it? Buy a second one used for short money and run the pair. You'll double power a lot easier/cheaper/faster than way than trying to buy a 2500W offering from a higher tier company. IMO Hifonics is probably the upper end of the "budget" brands anyway, so your next step is going to be pricey from there and you may not even need to go that far.

 

[bebitte3o 10+ year member]

Wow this thread turn in a very good tecnical talking!

Audio is not simple !