Speakers and ohms
Sep 17, 2004 at 7:18 PM Thread Starter Post #1 of 11

pnrgi

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Ok, i got a full tower set of 6ohm yamaha speakers. and i have a Harkar reciver, thats 8ohm only, and 55watt per channel.

Whats the deal, the speakers work fine, its just less resistance, so what its going to act like more watts going to the speakers?

the speakers handle up to 150, so i dont think its an issue.

But can someone explain this to me please?
 
Sep 17, 2004 at 7:20 PM Post #2 of 11
The danger is to the amp, not the speakers. Some amps can't handle putting out that much current. You should be fine, though. Most commercial speakers dip into the 3-4 ohm area when they are labelled "8" ohms nominal. Your 6 ohms speakers probably won't dip much worse than that.
 
Sep 17, 2004 at 10:41 PM Post #3 of 11
So i could blow out my reciever?

I dont understand, the reciever's amp puts out more power or something? Can you explain it further or point me in a direction where i could learn about it.
 
Sep 17, 2004 at 10:58 PM Post #4 of 11
The lower the impedance on the speaker, the more power the receiver puts out. With cheap receivers, some of them can't handle putting out that much power and will overheat or start oscillating and putting out DC, really bad stuff. That could fry your speakers - or your amp could overheat etc. These days, there are usually safeguard measures against stuff like that, but you never know.

The thing with commercial gear is that they all post specs that make themselves look good. Commercial speakers REGULARLY dip into the 3-4 ohm area on some frequencies when they are marked 8 ohm. If a commercial speaker is marked 4 ohm, you can bet it goes down to 2 ohms or maybe even a bit lower. So a receiver labelled 8 ohm should fully expect to be run with speakers that dip down to at least 4 ohms. Your 6 ohm speaker probably isn't all that far off, it's just that the average nominal impedance is a bit lower than in an 8 ohm speaker.
 
Sep 18, 2004 at 1:27 PM Post #5 of 11
Thank you very much for taking the time to explaining that.
 
Sep 18, 2004 at 7:04 PM Post #6 of 11
I hope I didn't say anything wrong here
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Sep 18, 2004 at 7:41 PM Post #7 of 11
ooheadsoo is spot on, as usual. I would offer another piece of information. Amplifiers have 2 limits. There is the voltage limit. When that is surpassed, audible clipping happens. If driven into clipping to far, or for too long, tweeters become flashbulbs. The other limit is the current capability of the output stages of the amp. Exceeding the current limit will do bad things to the amp, sometimes resulting in the escape of smoke. If you are not aware, electrical circuits are powered by smoke that flows inside the wires. Once the smoke escapes, the component won't work anymore.

More seriously, since the current vs voltage relationship (ohm's law) is a function of resistance (impedance is analogous to resistance) manufacturers rate the output of their amps to make sure that you hit clipping as an audible warning that something is wrong before you hit the current limit. Using a lower impedance speaker may run the risk of hitting the current limit first. I do not think that you have gone too far, but be careful if you run at high volume levels.

Sorry if I am redundant. Just trying to simplify. btw this is the reason that bridgeable amps have an impedance rating that is double in bridged mode, because current through the amp doubles in bridged mode, but most don't have double the current margin.


gerG
 
Sep 21, 2004 at 11:31 PM Post #8 of 11
goodness, thats a mouthfull.

Well, yeah these speakers are being run insanly loud, about 105-110 Db by my guestimation. So i should be worried. hmm. Will it get worse over time, i have been playing them loud like that for a few months. will the amp evenutully just die one night?
 
Sep 24, 2004 at 4:07 PM Post #9 of 11
Modern ht receivers all have protective circuits - so you shouldn't have anything to worry about.

Greetings from Hannover!

Manfred / lini
 
Sep 24, 2004 at 6:31 PM Post #10 of 11
Oops, sorry, I spaced out and forgot about this thread.

Lini, do the protection circuits guard against high current? It makes sense, since they will usually trip for a dead short. The concern at that point is the pop that happens when the protection kicks in.

pnrgi, it surprises me that your receiver is 8 ohms min. Is that for 2 or 4 speakers? Receivers have historically been rated for 4 ohm loads, which puts an 8 ohm restriction if running 2 per side in parallel.

I also need to scold you for running those things so loud. Please take care of your ears. Once you burn them off they don't grow back
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gerG
 
Sep 26, 2004 at 3:16 PM Post #11 of 11
yeah, the receiver is only 8 ohms. i was suprized to by that becasue even my 10 year old sony str-d911 has a 4-8 ohm switch....


Anyway, yeah, i know its REALLY bad for my ears. the only thing i can say in my defence is im drunk when im listening to it that loud.
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But yeah, i am starting to worry about my poor ears, i listen to things way to loud.

And thanks agian for all your help!!!
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