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artofali
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my reciever is rejecting my speakers!

hello,

this is probably a completly assinine question, but here it goes. i just bought some event 20/20 v2 passive moniter speakers, and when i hooked them up to my reciever and gave a listen they worked fine until i turned the volume up on my reciever (it was set to very low) and as soon as i did, my reciever flashed "overload" a few times then shut itself off.

does this mean that the speakers are demanding more power than my reciever can handle or the other way around? and in any case what should i do? im guesing im going to have to buy a amp, which one should i get to work with the speakers? in the manuel for the speakers it says there 88db @ 1W/1M, and elswere online i have seen the label 150watts atrributed to them.

so i guess my question is what are the best and CHEAPEST (under a 100 dollars) amp i can buy for my speakers. and also will there be any problem connecting the amp to my reciever?

thanks,

-Ali

Yiangos
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Re: my reciever is rejecting my speakers!

And i suppose everything comes back to normal a few seconds after you turn the volume down,right? Without knowing "event" loudspeakers or which receiver you are using
i bet the speakers are 4ohms and your receiver can't handle such "difficult" load.

Buddha
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Re: my reciever is rejecting my speakers!

I'm thinking that, as usual, Yiangos is correct.

Scooter123
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Re: my reciever is rejecting my speakers!

As others have noted, your new speakers are probably somewhat low impedence speakeres. Fyi, impedence is the "complex" resistance of a "load". In the case of a low impedence speaker, it means that your amplifier is seeing a "short circuit" because it wasn't designed for impedence loads this low. It will probably make an audiophile shudder but one solution would be to try increasing the impedence by adding a resistor to each speaker. Check at Radio Shack and online retailers for a 4 ohm, 10 to 20 watt resistor. Then connect the resistor between ONE terminal on each speaker and the speaker wire. That will raise the impedence and make these speakers usable with your amplifier. Of course it will also reduce the maximum volume output of the speakers by 3db but in a smallish room that shouldn't be a problem.

Now, a litttle discussion of Ohm's law. You may find it impossible to find a 4 ohm, 20 watt resistor. If so knowing a little bit about Ohm's law will help. BTW, it will probably be much easier to end at 5 ohms instead of 4, don't sweat that, 5 ohms is close enough. If you can only find a 10 ohm, 10 watt resistor, it's pretty easy to use Ohms law to make 2 of these into a single 5 ohm, 20 watt resistor. You just solder the 2 of them side by side. With resistors of equal value connecting them "side by side" (parallel) will HALVE the resistance of each PAIR. When you connect resistors "end to end" (series) you will DOUBLE the resistance of each pair. Mathematically, the formula for parallel resistors is => 1/(1/R + 1/R ...) = Rf. The formula for series resistors is (R + R ....) = Rf. Also note the power rating of resistors in parallel is additive so 2, 10 watt resistors can take 20 watts, 3, 10 watt resistors in parallel can handle 30 watts.

As for your amplifier question, that probably is NOT possible on a 100 dollar budget. Your most likely option at this price level is to shop for a used amplifier on ebay. Spedifically, I would look for either a Yamaha A-700 or A-900 Integrated amplifier. They were good amps capable of driving loads as low as 2 ohms at moderate listening levels and might be sold near you price range. For a new amplifier, it cannot be done at this price. To give you some idea of the cost, I will be picking up my new amp today. It's an NAD C-372, has 150 wpc with a 50 amp output capability, and it sells for about 900 dollars. Low impedence load require the use of a high current capable amplifier and that means an expensive amplifier. That NAD is about the least expensive high current amplifier that I could find.

So, your either left with buying a used amplifer, with it's potential for problems (capacitors get old and require replacement after a number of years) or using some very inexpensive resistors. About 10 bucks spent at Radio Shack will solve your problem, just make sure to only buy high wattage rated resistors. If you use the typical 1/2 or 1/4 watt resistors they will blow the first time you turn up the volume.

CECE
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Re: my reciever is rejecting my speakers!

IMPEDANCE is NOT OHM'S law but the impedance formula....Z= Xc, Xl, R and Freq. OHM had his evil and opposite brother MHO....I think different fathers same mother....yup, even back in the 1800's nothing has changed has it?

Buddha
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Re: my reciever is rejecting my speakers!

Before Ebay, check around your local used electronics shops.

Every once in a while, you can get lucky and hook up with a cool shop that will be a great resource for you.

They can be cheaper than Ebay, too!

Scooter123
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Re: my reciever is rejecting my speakers!

Hey, don't fault me for using the wrong label, it's been over 30 years since I studied this stuff and I am an ME, not an EE. The fact is that the least expensive option for this person is to add some resistors in series to his speakers. Lets face it, a 100 dollar budget in today's Audio is a "drop in a bucket".

artofali
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Re: my reciever is rejecting my speakers!

Thanks everyone!

Im going to go to looking for some resisters tomorrow, but more than likely im going to just go and pick up a new 500-watt receiver for about 100-200 bucks. i noticed that my receiver is a embarrassingly 260 watts, barely enough to power just one of my speakers. but ill see if the receiver thing works, that may just save me some time and trouble.

cyclebrain
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Re: my reciever is rejecting my speakers!


Quote:
Thanks everyone!

Im going to go to looking for some resisters tomorrow, but more than likely im going to just go and pick up a new 500-watt receiver for about 100-200 bucks. i noticed that my receiver is a embarrassingly 260 watts, barely enough to power just one of my speakers. but ill see if the receiver thing works, that may just save me some time and trouble.


So this person is already putting his stereo into limit mode trying to listen to it, and some of you are suggesting that he add a power wasting resister in series with his speakers? Now he will need to increase the volume setting to get the same power to his speakers? How could this be a bad idea?

Scooter123
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Re: my reciever is rejecting my speakers!

He is probably using a "consumer" grade reciever picked up at one of the big box stores. You know, one of those things rated in "music power" instead of continuous power into a real world load. Which may have a load sensing circuit built into it to protect the op amps used to provide the power. If it's a simple impedence sensing design it probably doesn't take much volume to trigger the circuit. So if you connect a set of speakers with only 2 ohms of load the amplifier may "trip out" at a very low volume output as described. Add 4, or 5 Ohms to the load and that problem may very well disapear. It's not a perfect solution but it is cheap enough that it's worth a try.

Of course, I do have to wonder where one can purchase a 500 watt per channel amplifier for just 200 bucks, last time I looked amplifiers that actually delivered this level of power output cost well into the THOUSANDS.

RRR925
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Re: my reciever is rejecting my speakers!

Art is probably referring to 100w/c home theater receivers that are routinely advertised as "500", "600" or "700 watts total power". Beware!

chadnliz
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Re: my reciever is rejecting my speakers!

Is there any remote chance the wires are bad, worn or making contact with eachother somewhere in its run? Years ago I wired my house for surround speakers, I stapled the wires to baseboard and a staple went thru the wires jacket and caused contact to both Neg and Pos legs of the speaker wire, my then reciever did the same thing, found the problem and it never happened again, I once drove Teledyne AR9 speakers with an Onkyo reciever.....those are a VERY hard speaker to drive, and the reciever although not very well in the big picture of things, handled every level of volume/power I threw at it.

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