I'm thinking of connecting a pair of 8 ohm speakers to an add-on 45W amplifier where the speaker connections are rated at 4 ohms. I don't want to damage anything so was wondering if its OK.
2007-05-17 14:17:29 · 9 answers · asked by Anonymous in Consumer Electronics ➔ Home Theater
Lots of wrong answers here. You won't damage or in any way harm your system by running a higher ohm load than rated.
What happens:
The amp puts out voltage and has amperage potential. You can put an impedance of 100,000 Ohms on the amp and turn the amp up with a sine wave, and you will see the voltage rise. As the impedance lowers, you don't swing higher voltage, you pass more amperage. As the impedance continues to lower, the amperage can increase to destructive levels. That is why you must not go lower than rated on the ohms, but higher is fine. If you look at high-end stuff, they talk about the amperage potential, and this is only used in low-ohm speakers.
Long answer, but it should make more sense to you as to WHY 8 ohm speakers are fine when mated to a four-ohm amp. The power potential of the amp is reduced (you won't have as many watts), but that just makes the amp's life easier!
Hope this helps!
2007-05-18 02:57:50 · answer #1 · answered by piano guy 4 · 2⤊ 1⤋
Not a problem. I've done it lots of times. The fact is that speaker impedance isn't constant, but varies a lot with frequency. They could be as little as 2 ohms at some freqs and 20 ohms at others.
If you're really worried about it (for no good reason), buy a second pair of the same kind of speakers and have two on each side, the two connected in parallel, which will let your amp see 4 ohms.
I used Double Advents one time; they were great.
2007-05-17 14:27:55 · answer #2 · answered by OR1234 7 · 2⤊ 1⤋
Hi no need to worry .if the speaker rating is higher than the amp the actual sound output will be a bit lower than an 8 ohm speaker. back in 1968 i had a pair of speakers rated 16 ohms and the amp was 8 ohms and nothing happened except a small drop in sound level.If you reverse the situation by having speakers at 4 ohms and amp at 8 ohms then the speakers will sound louder and the amp will release more wattage.
2007-05-18 02:33:40 · answer #3 · answered by ROBERT P 7 · 2⤊ 1⤋
Yes, it really does make a big difference. Ohm ratings on the speakers and amplifiers are there for a huge reason. The coil magnet and crossover board on a speaker are designed at an ohm rating showing what the amp puts out (resistant wise) and what the speaker needs to run properly (amperage wise) It would be like using 90 volts of electricity to run a lightbulb instead of 120 volts. The bulb will work, but you will go through more light bulbs than if you had 120 volts. After a while the socket or switch may no longer work. You can actually ruin both your speakers and your amplifier by having the wrong ohm rating hooked up. (the amp will go first in your case, because the draw of the speakers is more than the amp puts out, so the amp will work overtime.) One of the biggest problems you'll notice though is the sound quality isn't just right.
If you'd like to learn about OHM's law you can go here; http://www.the12volt.com/ohm/ohmslaw.asp
My advice to you is to buy speakers designed to run at the output ohm of the amp. You'll find that your system will last a whole lot longer.
2007-05-17 16:50:19 · answer #4 · answered by x5bp 2 · 1⤊ 4⤋
Piano Guy is right. As long as your ohm rating on the speakers is higher than the minimal rating of the amplifier you will not damage the amp. This is not optimal of course. Its always best to match your impedances. Electrical Engineers would look at the Thevenin equivalent of your black box(amplifier) and the maximum power the circuit can produce is when the load matches your Thevenin equivalent. Anyway, i am rambling.
2007-05-18 07:43:37 · answer #5 · answered by Brian V 1 · 1⤊ 1⤋
If the amp is not rated for that IMPEDANCE then don't use it. The possibility of damage is present depending on the method of signal to final power output coupling. In car audio applications this kind of setup is common and does not affect anything but rated power output. Since 12V systems can't directly couple this is a safe thing to do in most cases.
However depending on the manufacture they may to save cost directly couple. This will most likely cause the amp to overheat and damage a MOSFET transistor and will then need to be replaced, this also can damage the power supply of the receiver, then you are toast.
You have a couple of options
1) purchase or build a LISN (line impedance stabilization network) to correct the impedance ( this is what higher end manufactures add internally and the rate ohm ratings from 2-16.
2) use the receiver as a pre amp and connect a additional discrete amplifier to the system.
3) contact the manufacture or consult your owners manual for details on this most will spell it out in the manual as what you can and cannot hook up.
If you have further questions let me know.
2007-05-18 05:43:34 · answer #6 · answered by Anonymous · 0⤊ 4⤋
No, it won't hurt anything. The "4 ohm" rating on your amplifier is the nominal *minimum* impedance the amp is designed to handle.
2007-05-17 21:38:39 · answer #7 · answered by Anonymous · 3⤊ 1⤋
I have seen some answers here that are correct and are also incorrect. I work for a speaker company called energy speakers, and in theory you won't damage your speakers but you do run the risk of damaging your amplifier. I personally wouldn't do it.
2007-05-19 23:35:19 · answer #8 · answered by Anonymous · 1⤊ 2⤋
yes you will damage it
8 ohms are rated for car systems
2007-05-17 17:14:10 · answer #9 · answered by Anonymous · 2⤊ 6⤋