8ohms vs 16ohms
- Thread starter newking70
- Start date
marvar
New member
Re: 8ohms vs 16ohms
8
Sorry, I couldn't resist.:banana:
It all depends on what load your speakers are- technically, there is no difference in output as long as the amp and speakers are running at the same ohms, or how you amp works(some SS amps increase power with lower ohm load) 100watts@8ohms with an 8ohm cab is the same as 100watts@16 ohms with a 16 ohm load, a watt is a watt, is a watt, but some people claim they can hear a difference. Some people also claim that mis-matching the load (in a tube amp) makes for a different tone, but all I'll say is run your head at the same ohm setting as your speakers or cab or you risk burning up your output transformer. The exception is if your amp is solid state- then never run a lower load than the amp's lowest ohm rating.
8
Sorry, I couldn't resist.:banana:
It all depends on what load your speakers are- technically, there is no difference in output as long as the amp and speakers are running at the same ohms, or how you amp works(some SS amps increase power with lower ohm load) 100watts@8ohms with an 8ohm cab is the same as 100watts@16 ohms with a 16 ohm load, a watt is a watt, is a watt, but some people claim they can hear a difference. Some people also claim that mis-matching the load (in a tube amp) makes for a different tone, but all I'll say is run your head at the same ohm setting as your speakers or cab or you risk burning up your output transformer. The exception is if your amp is solid state- then never run a lower load than the amp's lowest ohm rating.
Last edited:
Ray 911S
New member
Re: 8ohms vs 16ohms
Maybe I miss the point, but here goes...
An ohm is a measure of resistance. Speakers are the "load" or resistance in the output circuit of your amplifier. An ohm is related to your amplifier's power (current) in this way: Power = voltage / resistance (I = E/R). So, at a constant voltage a higher load (more resistance) will require more power. All things being equal, since 8 ohms is less than 16 ohms of resistance there will be more "power" in the circuit. Generally an 8 ohm speaker will seem louder than a 16 ohm speaker all else equal.
The problem is that if your solid state amp is designed to operate at a certain power level, it must operate at the specified load (resitance in ohms). Lower resistance increases power - maybe too much power for your amp - and this can blow your output section. With lower resistance the output section must make more power and this can cause it to overheat and burn out. Tubes are generally more forgiving, but not indestructible.
Speakers will be rated by load and power. 150 watts at 8 ohms for instance. Watts are power. When the speaker label quotes more than one level - one at 8 ohms and another at 16 ohms, you will see that they are related by I=E/R. When E is constant, I and R are related as shown on the label.
This is all just academic text book crap though. :laugh2: But I still wouldn't run a 4 ohm speaker on an amp the prefers 8 or 16 ohms. At least not at high volume.
Maybe I miss the point, but here goes...
An ohm is a measure of resistance. Speakers are the "load" or resistance in the output circuit of your amplifier. An ohm is related to your amplifier's power (current) in this way: Power = voltage / resistance (I = E/R). So, at a constant voltage a higher load (more resistance) will require more power. All things being equal, since 8 ohms is less than 16 ohms of resistance there will be more "power" in the circuit. Generally an 8 ohm speaker will seem louder than a 16 ohm speaker all else equal.
The problem is that if your solid state amp is designed to operate at a certain power level, it must operate at the specified load (resitance in ohms). Lower resistance increases power - maybe too much power for your amp - and this can blow your output section. With lower resistance the output section must make more power and this can cause it to overheat and burn out. Tubes are generally more forgiving, but not indestructible.
Speakers will be rated by load and power. 150 watts at 8 ohms for instance. Watts are power. When the speaker label quotes more than one level - one at 8 ohms and another at 16 ohms, you will see that they are related by I=E/R. When E is constant, I and R are related as shown on the label.
This is all just academic text book crap though. :laugh2: But I still wouldn't run a 4 ohm speaker on an amp the prefers 8 or 16 ohms. At least not at high volume.
marvar
New member
Re: 8ohms vs 16ohms
Yes, Ray, that is the technical discription of ohms.
Many tube amps have a multi-tap transformer, with some way to switch between 4,8,or 16 ohms. you set the switch to match your speaker load- but still, the amp is only putting out the specified wattage, at the given ohms/load setting. Say, if it's a 50 watt rated amp, it still will only make 50 watts into a 4, 8, or 16 ohm load.
Many solid state amps are rated by the ohm load, for instance, my peavey power amp says it makes 100 watts at 8 ohms, and 150 watts at 4 ohms. I beleave that SS amps are a bit more forgiving with a mismatch than tube amps as long as you don't have a load less than specified.
Yes, Ray, that is the technical discription of ohms.
Many tube amps have a multi-tap transformer, with some way to switch between 4,8,or 16 ohms. you set the switch to match your speaker load- but still, the amp is only putting out the specified wattage, at the given ohms/load setting. Say, if it's a 50 watt rated amp, it still will only make 50 watts into a 4, 8, or 16 ohm load.
Many solid state amps are rated by the ohm load, for instance, my peavey power amp says it makes 100 watts at 8 ohms, and 150 watts at 4 ohms. I beleave that SS amps are a bit more forgiving with a mismatch than tube amps as long as you don't have a load less than specified.
viewaskew2k5
New member
Re: 8ohms vs 16ohms
I think a MythBusters thing comes in handy right now.
Example. A ducks Quack. Does it Echo? Yes. But the human ear cant here it.
So. 8ohms V 16. Is there a Difference? Yes. But he human ear cant hear it!
I think a MythBusters thing comes in handy right now.
Example. A ducks Quack. Does it Echo? Yes. But the human ear cant here it.
So. 8ohms V 16. Is there a Difference? Yes. But he human ear cant hear it!
wixedmords
New member
Re: 8ohms vs 16ohms
The OT has to work harder with a higher impendance, I believe.
I don't believe there is any difference in volume, but the OT has to work to overcome the resistance. So what the ear will hear should be about he same.
Now, I have heard that OT's don't like to work with 4ohms or less, but I am not sure if that is a brand/model issue or an issue generically engineered into the device.
The OT has to work harder with a higher impendance, I believe.
I don't believe there is any difference in volume, but the OT has to work to overcome the resistance. So what the ear will hear should be about he same.
Now, I have heard that OT's don't like to work with 4ohms or less, but I am not sure if that is a brand/model issue or an issue generically engineered into the device.
modophoto
New member
Sludgenutz
New member
Re: 8ohms vs 16ohms
Sixteen Ohm speakers may allow half the amplifier's power through, but they may also be twice as efficient as an 8 ohm speaker. This is assuming the voice coils in each were wound with identical diameter gauge of wire, and the speaker magnet and construction are the same.
By nature, Solid state amps have a low output impedence, therefore NO output transformer is needed. As long as it is greater than than say a typical number of 6 Ohms, no damage will occur to the amplifier. We see this all the time when messing with solid state home HiFi and car audio amps. In practice it is generally OK for most to be run with infinite impedence...no speakers at all. Just don't "short" the two outputs + and - together.
Vacuum tube amps (I like the way the Brits call tubes "valves" myself) are high output impedence devices, which need an output transformer to match the speakers low impedence to the high impedence amplifier.
I will defer to this link for info after this point, although I wish I had a better one:
http://www.thegearpage.net/board/showthread.php?threadid=67069
Sixteen Ohm speakers may allow half the amplifier's power through, but they may also be twice as efficient as an 8 ohm speaker. This is assuming the voice coils in each were wound with identical diameter gauge of wire, and the speaker magnet and construction are the same.
By nature, Solid state amps have a low output impedence, therefore NO output transformer is needed. As long as it is greater than than say a typical number of 6 Ohms, no damage will occur to the amplifier. We see this all the time when messing with solid state home HiFi and car audio amps. In practice it is generally OK for most to be run with infinite impedence...no speakers at all. Just don't "short" the two outputs + and - together.
Vacuum tube amps (I like the way the Brits call tubes "valves" myself) are high output impedence devices, which need an output transformer to match the speakers low impedence to the high impedence amplifier.
I will defer to this link for info after this point, although I wish I had a better one:
http://www.thegearpage.net/board/showthread.php?threadid=67069
Last edited:
wixedmords
New member
Re: 8ohms vs 16ohms
That's a good reference Sludge.
John Phillips of TGP and Ed Green of Plexi Place/Marshall Law are my favorite reads.
That's a good reference Sludge.
John Phillips of TGP and Ed Green of Plexi Place/Marshall Law are my favorite reads.
