qball Posted March 8, 2002 Share Posted March 8, 2002 You guys don't seem to understand how this works. If you have a 500 Watt amp, that doens't mean that it magically provides 500 Watts to your speakers, only that it is capible of doing so. You seem to understand that power is dependant on the impedence of the speakers, and more specifically that it is inversely proportional. Meaning that if you have an amp that can do 100W for an 8Ohm load, then if you drop the load to 4Ohms, then it can do 200W, assuming it is 4Ohm stable. Now what you don't seem to understand is that Watts aren't something that's provided by an amplifier. All an amplifier does it output a signal at a given voltage. The speaker then draws current from the amplifier in terms of Ohm's law: I = V/R. So thus far, we have an amplifier providing a voltage, and a speaker drawing a current from the amplifier. Now to figure out the power used to drive the speaker and make sound waves (as well as any heat, etc generated as a side effect) can be determined by the equation: P = I*V. Substituting for I and you get P = V^2/R, thus Power (watts) = Voltage^2 (volts^2) / Resistance (Ohms). So this verifies what you know already, if you drop the impedence by a factor of 2, you raise the power by twice as many watts. The fundamental thing that you're missing is the issue of volts. The way an amplifier causes a speaker to vibrate is by sending an oscilating voltage to the speaker. Want it louder? Then the amp sends a higher voltage signal. So the number power you send to your speakers depends on the volume. Also, in terms of the speakers, there is no difference between 60W with a 4 ohm impedence and 60W with an 8 ohm impedence, it's still the same amount of power, the difference being that you won't have to turn the volume knob up as much to get to that power level with the lower impedence speakers. Where lower impedence can hurt you in in your amp. Amps are designed with a certain current in mind, so you can hurt your amp if you hook it up to a lower impedence load than it was designed for. When you buy passive speakers, they will have a rated output. The promedia sats don't have this rated spec, since they are designed to be used with the promedia amp. Just because the promedia amp is 60W doesn't mean that's all they can take, just that is what Klipsch is supplying them with. Even if that's really all they can take, you can avoid going over the limit simply by not blasting them any louder than you could with the integrated amp. So using an external amp to power your sats won't hurt your sats, though your amp might not like it if they are too low impedence (I seem to recall the promedia sats being rated around 6ish Ohms, not 4), but I'd say that most decent quality amps shouldn't have any problem with them. A note on the above: my calculations use the most basic circuit theory to elaborate my point, however a speaker isn't a straight resistor, so it's slightly more complicated than that... the principles still hold though. -Q Quote Link to comment Share on other sites More sharing options...
justin_tx_16 Posted March 8, 2002 Share Posted March 8, 2002 no, i do understand. the problem would be the one time accidental push of the volume knob and boom. now you have a bunch of broken sats. ------------------ -justin SoundWise Tech Support I am an amateur, if it is professional; ProMedia help you want email Amy or call her @ 1-888-554-5665 or for an RA# 800-554-7724 ext 5 Klipsch Home Audio help you want, email support@klipsch.com or call @ 1-800-KLIPSCH RA# Fax Number=317-860-9140 / Parts Department Fax Number=317-860-9150s> Quote Link to comment Share on other sites More sharing options...
KHarvey16 Posted March 9, 2002 Author Share Posted March 9, 2002 Wow. Thanks for the informative post, and you have just confirmed my earlier thought: I'm definitely not an expert . Ok, so now let me ask you a question....could I safely hook the sats up to the receiver itself? Looking at the online manual, it says the pro's need a min. of 4ohms. The receiver itself is rated to 6ohms, and is rated at 70 watts per channel at 8ohms. If I understood correctly, this would cause problems with the amp, right? Or no? By all means, if this setup could be accomplished safely, I would give it a shot. Quote Link to comment Share on other sites More sharing options...
TheEAR Posted March 11, 2002 Share Posted March 11, 2002 While qball gave you the basics about speakers and amps.Your ProMedia sats will not stress the amp too much if at all. Be sure to set the sats to SMALL in the reciever's menu.The ProMedia sats can be damaged if you dont cut the bass out.AT 80Hz the lowpass should prevent damage unless you drive the poor sats to high SPL. A subwoofer is a must,the ProMedia sats need help down low. The more bass the ProMedia sats get the less output you will get while operating the sats in a safe range. When you hear distortion turn the volume down.And use common sense.The ProMedia will not replace the Quintets,as the Quintets are much more robust,they can take much more abuse and still kick. TheEAR(s) Now theears Quote Link to comment Share on other sites More sharing options...
qball Posted March 11, 2002 Share Posted March 11, 2002 quote: Be sure to set the sats to SMALL in the reciever's menu.The ProMedia sats can be damaged if you dont cut the bass out.AT 80Hz the lowpass should prevent damage unless you drive the poor sats to high SPL. Aye, you'll get better sound, better efficiency and be less likely to hurt things. quote: A subwoofer is a must,the ProMedia sats need help down low. Yes again. I just use the promedia sub... you can hook it up to the sub-out on your receiver if you just get an adapter and use the volume/sub knobs on your preamp to set the sub volume. I also had to give the subwoofer channel a boost on the receiver since I guess it typically operates at a lower level than a full bandwidth signal (my speculation). quote: When you hear distortion turn the volume down.And use common sense. Yes. Like I said in my previous post, you're far more likely to blow a set of speakers with a 15 Watt amp that's cliping than with a solid quality amp that's running above the speakers rated input power. Like theEAR said, use your head and your ears... you can typically hear things that will be damaging. quote: no, i do understand. the problem would be the one time accidental push of the volume knob and boom. now you have a bunch of broken sats. I'm not convinced that you would blow your sats, however if there is going to be an overload point, it's going to be outside of the realm of reason. As in you'd really have to be trying to get that amp wide open to have a problem. And again like theEAR says, just use common sense. I'm running a Denon AVR-1802 to drive my sats and running the bass through the pro's sub as I describe earlier. I'm migrating the setup to a Paradigm Cinema series setup slowly, and found this to be the best way of doing with trickle cash as opposed to blowing $1200 all at once. -Q Quote Link to comment Share on other sites More sharing options...
KHarvey16 Posted March 12, 2002 Author Share Posted March 12, 2002 Hehe...trickle cash. I have that system too . I have also noticed that sub outs are generally set lower than the other channels. I've tried hooking just the sub up to my dvd player and I have to turn it up very loud in order to get acceptable volume. But, like you said, the receiver has an adjustment for that sort of thing. Well then, I guess I'll give it a try. Thanks again guys....later. Quote Link to comment Share on other sites More sharing options...
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