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The amplifier will have an output impedance of around 0.04 ohms. In hi-fi we have always impedance bridging. Zout << Zin. That means the output impedance of the amplifier is much less than the input impedance of the loud speaker.
The damping factor Df = Zin / Zout tells you what Zout is.
Zout = Zin/Df.
If the damping factor Df = 200 and the loudspeaker impedance is Zin = 8 ohms, the output impedance of the amplifier is Zout = 8 / 200 = 0.04 ohms.
You see, there is no "8 ohm amplifier" on the market with a 8 ohm output impedance.
Scroll down to related links and look at "Voltage Bridging or impedance bridging - Zout < Zin".
Answer #3Actually, it's not a myth. Just a simple misunderstanding. An "8 ohm" amp does not mean it has an 8 ohm output impedance, it means the amp is designed to drive an 8 ohm load. Let me explain (warning, this is long, with math!).Let's say I want to design an amp to provide 50 watts RMS into an eight ohm load with an input of 0dbv (which is 0.775VRMS).
How much voltage and current will I need to produce 50 watts? According to Ohm's Law, P=I^2R, so:
50watts=I^2 X 8ohms
I^2 = 50 / 8 = 6.25
I = sqrt 6.25 = 2.5
We will need 2.5 amps current capacity. Now that we know amps, let's figure volts. E=IR, so:
E = 2.5 X 8 = 20
We will need 20 volts RMS.
Now, how about voltage gain? Our output is 20V, our input is 0.775V, so the necessary gain is:
20 / 0.775 = 25.8
As you can see, this amp will need to supply 2.5A and 20V with a voltage gain of about 26. The design engineer will have to build the power supply with enough voltage to reach 20V at the output, and use output transistors capable of 2.5A.
I won't write out the calculations for a 4 ohm amp, you can do them yourself just like I did above, substituting 4 for 8. If you do, you will find the amp designed for a 4 ohm load will need to supply about 3.5A and 14V, with a voltage gain of 18. Note the voltage is lower, but the current is higher!
If I design this amp for a 4 ohm load, I will need bigger output transistors (3.5A vs 2.5A), but can get away with a lower voltage power supply (14V vs 20V).
See how the design is VERY dependant on which speaker impedance I intend on driving? Now lets see the ramifications of using the "wrong" speaker on an amp.
First, let's put an 8 ohm speaker on an amp designed for a 4 ohm load. We already know from our design calcs above that the amp will be designed to supply 14V. This is less than the 20V needed to drive the 8 ohm speaker to 50 watts, so it is obvious we will not reach full power. We will only get (I = E / R) 14/8 = 1.75 amps, and therefore (P = E I) 14 X 1.75 = 24.5 watts output.
So, if we put an 8 ohm speaker on an amp designed to drive an 4 ohm load, we will get less power, in this case about half. If we try to compensate by turning up the gain or increasing the input signal, the signal will clip and distort because the power supply can't reach the required output voltage. Note that no damage occurs to the amp (although some speakers can be damaged by driving them with a clipped signal), and the setup will sound fine as long as we keep the volume low enough so that our power is less than 24.5 watts.
Ah, but what about the reverse, putting a 4 ohm speaker on an amp designed for an 8 ohm load?
Let's do this: first install a correct 8 ohm speaker on the amp, feed an audio signal in, and adjust the gain so that 50 watts is produced. We already know from our calcs that at this point the amp will be producing 20V at about 2.5A.
Now, remove the 8 ohm speaker and without changing anything else, install a 4 ohm speaker. What happens? Well, if you feed a 4 ohm speaker with 20V, what is the current drawn? I = E / R, so:
I = 20 / 4 = 5A
Oops, this is a problem. The speaker will try to draw 5A, but our output transistors are designed for only 2.5A, I see smoke!
What is the power at this level? P = I^2 R, so:
P = 5^2 X 4 = 100
Oh, another problem. Our power supply is designed for 50 watts, but we are now supplying 100! More smoke.
Now, what if we turn the gain down until the current drops to 2.5A? well, at least no more smoke, since we are no longer overloading the amp beyond it's rated limit. What will the power output be? P = I^2 R, so:
P = 2.5^2 X 4 = 25
Again, if we turn down the gain such that 25 watts or less are delivered, everything will be fine, but if we try to drive the speaker to 50 watts, we may overload the output transistors. And since this amp has higher gain (26 vs 18), and it has a higher voltage power supply, we can drive the speaker to power levels approaching 100 watts, which will certainly pop the output transistors, probably burn up the power supply, and most likely ruin the speaker too.
So, answer #1 is correct. (Yes, I am a design engineer. And, yes, I wrote answer #1...)
Answer #2 is correct as well. An 8 ohm amp does not have an output impedance of 8 ohms. It is indeed much lower. But the question asker meant an amp designed for 8 ohm speakers when he asked the question, and these definitely do exist. And using a 4 ohm speaker on such an amp can cause it to fail. Ask me how I know this... I am no stranger to smoke, believe me.
Answer #4
According to legend and conventional wisdom, solid state (transistor) amplifiers can drive higher impedances than their rating demands. So a transistor amp with a label saying "4-ohm" will drive 4, 8, and 16 ohms with no troubles. You can go up but not down. Don't try 2 ohms.
Older legends say that tube amplifiers can drive lower impedances than their rating demands. So a tube amp with a label saying "8-ohm" may drive 4 and 8 ohms. You can go down but not up. Don't try 16 ohms. And never run a tube amplifier without speakers attached. Other legends of the tube age say that any attempt to use a tube amp with speakers of different impedance may cause damage to the amplifier.
Yes, but it will not be as loud as a 4-ohm cabinet. It's a myth. There is really no 4Ohm amplifier on the market. And there never was. The amplifier will have an output impedance of around 0.04 ohms. In hi-fi we have always impedance bridging. Zout << Zin. That means the output impedance of the amplifier is much less than the input impedance of the loud speaker. The damping factor Df = Zin / Zout tells you what Zout is. Zout = Zin/Df. If the damping factor Df = 200 and the loudspeaker impedance is Zin = 4 ohms, the output impedance of the amplifier is Zout = 4 / 200 = 0.02 ohms. You see, there is no "4 ohm amplifier" on the market with a 4 ohm output impedance. Scroll down to related links and look at "Voltage Bridging or impedance bridging - Zout < Zin".
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Are logitech Z-680 speakers 8 ohm?
the speakers are 8kOhm or 8000Ohm
I HAVE A crunch 1000.1 AMP THAT im trying to push 1 punch p3 15 subwoofer how do i wire it?
If youre running a single woofer get the dual 2 ohm woofer. Wire them parallel, which will bring it down to 1 ohm when you put it on the amp. 1 ohm will pull the most power from the amp
Will 4 5.5 ohm speakers connect to an amplifier with a 16 ohm output impedance?
Yes, they will. One can connect anything to anything else. Will it work? If so, how well? Is it safe? If the four speakers are connected in series, the total impedance of the speakers will be the sum of all the impedances of the speakers: 5.5 + 5.5 + 5.5 + 5.5 = 22 ohms The 22 ohm load on the amplifier will be a bit higher than the amp has been designed for, but the setup will work. At modest power levels it is doubtful that anything audible will be noticeable because of that slight mismatch, and as long as one doesn't crank it up too high, the amp won't notice the difference. It would be wise when hooking up the speakers to insure they are all hooked up in phase... Something important has to be added: There is really no 16 ohm amplifier on the market. The amplifier will have an output impedance of around 0.08 ohms. In hi-fi we have always impedance bridging. Zout
110v and the current is 10 a what is the resistance?
Resistance is Volts over Current 11 Ohm = 110Volt / 10 Amp
Who is law states that it takes one volt to push one amp through 1 ohm of resistance?
Ohms Law.
Can 270 watt speakers damage a 125 watt amp?
Not unless the speakers are rated at a resistance (ohms) that is incompatible with the amp. Speakers don't generate power, the rating only tells you how much they can handle. So, speakers capable of up to 270 watts, can certainly handle 125 watts. However, if the amp is not 1-ohm stable and the speakers are 1-ohm, you could cause the amp to cut out and overheat depending on the protection mechanism of the amp.
What ohms am i running if i have two 4 ohm speakers hooked up to my amp vs two 2 ohm speakers?
Don't know how you have subs wired but should be 4 ohm load is what your amp will see.
Can you use a 6 ohm and a 16 ohm speakers with a 6 ohm amp?
No. Not and maintain good balance and dynamic range.
I have a 2 channel nitro amp 2000watts amp and it always gets hot after 10min. it's been hooked it up to several cars and it's the only amp that gives trouble every other amp works fine?
If it's running so hot you can't touch it, in most cases it will be due to either the way the speakers are hooked up or the impedence of the speakers. You can incresse the resistance to the amp to have it run cooler by connecting speakers in series or getting speakers with a higher ohm rating. The lower the resistance (2 ohm, 4 ohm, 8 ohm) the more current flows though the amp making it hotter. Remember if you hook multiple speakers in parallel it will cut the resistance in half. So if you connect speakers that are 4 ohm to the same channel you are running at 2 ohm. Check your amp's ratings.
Will 8 ohm sub woofers work with a 4 ohm amp?
if you put 2, 8 ohm speakers together on the same channel you will trick the amp into seeing a 4 ohm load, it is not advisable to run a 8 ohm coiled speaker on a 4 ohm amp unless you do the above. So if you want to run 2 8 ohm speakers from a 4 ohm amp this will work the best although the amp will need to be hefty as its worse to underpower a sub than overpower it! I have used a 8 ohm speaker myself on a car amp and had no problems but it was not a cheap entry level amp! some amps will take it, others will get hot and enter protection mode. Hope this helps!!!
What is 6ohm in amps?
Ohms is a measurement of resistance between the amp and speakers. Most home audio is 8 ohm, if you run 4 or 6 ohm speakers you cut resistance down and get more power out of the amp. Say your stereo is 100X2 @ 8ohm, if you use 4 ohm speakers you should get 50% more power BUT the amp is working twice as hard and can burn up.
Can I connect two 2 ohm speakers to the front channels of my amp and then connect 2 4 ohm speakers to the rear channels of my 4 channel amp?
This depends on your amplifier's specifications. i would recommend looking in the amplifier's service manual to avoid disapointment or damage to your amplifier or speakers.
Can you hook up two 8 ohm svc subwoofers to a one channel amp?
If you connect two 8 ohm speakers to the average car amp, then yes, probably. Most car amps can handle a 4 ohm load, which is what it would be.
Can you run 4ohm resistor to make 4 ohms speakers 2 ohm?
Yes, you can safely use a 4 ohm amp with one 8 ohm speaker, but you will not achieve full power. The 4 ohm amp is designed to supply a certain voltage into a 4 ohm speaker. Supplying that same voltage to an 8 ohm speaker will result in half the power, or -3dB. For maximum power, use a 4 ohm speaker, or two 8 ohm speakers in parallel.
Are kicker L7s good speakers and what kind of amp do I need to power 2-15 inch subs?
Yes, the L-7s are great. For the amp, you first need to find out whether the sub woofers are 2-ohm, 4-ohm, or 8-ohm. Depending on the answer to that question will determine whether or not you'll need a mono amp or a dual channel amp as well as the wattage.
Can you use 4 ohms speakers and 8 ohm speakers on the same amp?
The short answer is yes, the long answer is maybe. Example: my Toyota's stock CD player says on it specifically, ''4 ohm speakers'', the stock speakers, however, say they are 6 ohms and they measured on a volt meter at 6 ohms. Certain higher end car audio speakers are 2 ohms but are designed for 4 ohm head units and 4 ohm head units can power 2 ohm car speakers. 4 ohm and 8 ohm speakers will work, however, different ohms can (but not always) cause different volumes out of each respective speaker. If your equipment if really old or really crappy it might get fried or if it is modern and of good quality it might get fried if you run the amp at the higher end of its output (high volume). Short answer, you will be fine just don't ask the amp to work super hard. Medium answer, I wouldn't bet more than a few hundred bucks of audio equipment on it and don't stress the amp. Long answer, its complicated and always best to match ohms even though the ohm rating is an average and 4 ohm speakers can present ohm loads of way less than 4 to over 10 depending on their output at the time. Also if you ask different people you'll get different answers.
Whats the speaker sizes in a 2005 impala?
The front speakers should be 6.5" and the rear should be 6x9". You will want to make sure you have the correct ohm speakers though. My 2004 impala has 2ohm speakers and my friends has 4ohm speakers. You can put 4 ohm speakers in a 2 ohm system but your sound quality will suffer greatly. Do not put 2 ohm speakers in a 4 ohm system though, that will cause bigger problems.
