Speaker Ohms

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Shout It Out

Shout It Out

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I dont know if I can ask this in here, but it seemed to be the right place...Can I hook up a 6 ohm speaker to an 8 ohm amp??
 
Yes you can since the amp has the adequate amount of power to handle the speaker.
 
Whoah, hang on.

There are a couple of things you need to double-check. First, you need to check if your "8 ohm" amplifier is rated for 8 ohms only. Some amps are rated at 4 ohms and 8 ohms, some are rated at 8 ohms only. If your amp is rated for 8 ohms only I would not recommend using it to drive a 6 ohm load as you could be putting undue stress on a less-than-robust amplifier design. Plus the lower impedance load is going to have an effect on the working output wattage of the amplifier; the 8 ohm numbers for amp wattage will not be reliable in determining whether your amp matches up with your speakers OK in the wattage column.

If your amp is rated for 4-to-8 ohms, you should be OK on that side; what you'd need to do is take a look at the specified wattage ratings for that amp at each impedance level and calculate the rating that would fall in the middle. That should give you a good working approximation of the amp's rating at 6 ohms. Then you can use that number to compare against the speaker ratings to determine if you have a good match.

Typically you'll want the amplifier's RMS wattage rating to be somewhere aorund 75-80% (give or take a few percent) of the peak rating of the loudspeaker, though that depends a great deal on the discipline of the person running the amp's volume control.

G.
 
SouthSIDE Glen said:
Whoah, hang on.

There are a couple of things you need to double-check. First, you need to check if your "8 ohm" amplifier is rated for 8 ohms only. Some amps are rated at 4 ohms and 8 ohms, some are rated at 8 ohms only. If your amp is rated for 8 ohms only I would not recommend using it to drive a 6 ohm load as you could be putting undue stress on a less-than-robust amplifier design. Plus the lower impedance load is going to have an effect on the working output wattage of the amplifier; the 8 ohm numbers for amp wattage will not be reliable in determining whether your amp matches up with your speakers OK in the wattage column.

If your amp is rated for 4-to-8 ohms, you should be OK on that side; what you'd need to do is take a look at the specified wattage ratings for that amp at each impedance level and calculate the rating that would fall in the middle. That should give you a good working approximation of the amp's rating at 6 ohms. Then you can use that number to compare against the speaker ratings to determine if you have a good match.

Typically you'll want the amplifier's RMS wattage rating to be somewhere aorund 75-80% (give or take a few percent) of the peak rating of the loudspeaker, though that depends a great deal on the discipline of the person running the amp's volume control.

G.

that's just what I was gonna say........... :D

well not word for word, but the basic points are the same

I constantly have to check one of the bassists that comes here as no matter how often I tell him about ohmage etc etc he occasionally connects 2x4ohm cabs to an amp that won't go under 4 ohms!!!!
 
SouthSIDE Glen said:
Whoah, hang on.

There are a couple of things you need to double-check. First, you need to check if your "8 ohm" amplifier is rated for 8 ohms only. Some amps are rated at 4 ohms and 8 ohms, some are rated at 8 ohms only. If your amp is rated for 8 ohms only I would not recommend using it to drive a 6 ohm load as you could be putting undue stress on a less-than-robust amplifier design. Plus the lower impedance load is going to have an effect on the working output wattage of the amplifier; the 8 ohm numbers for amp wattage will not be reliable in determining whether your amp matches up with your speakers OK in the wattage column.

If your amp is rated for 4-to-8 ohms, you should be OK on that side; what you'd need to do is take a look at the specified wattage ratings for that amp at each impedance level and calculate the rating that would fall in the middle. That should give you a good working approximation of the amp's rating at 6 ohms. Then you can use that number to compare against the speaker ratings to determine if you have a good match.

Typically you'll want the amplifier's RMS wattage rating to be somewhere aorund 75-80% (give or take a few percent) of the peak rating of the loudspeaker, though that depends a great deal on the discipline of the person running the amp's volume control.

G.

Good post!

Hopefully Shout It Out didn't "go for it" before seeing your post.
 
also how did you come up with 6 ohm for the speaker. If its is labled that fine. But if you put an ohm meter across the coil and come up with between 6-6.6 ohms you have in your hand an 8 ohm speaker anyway. Seeing as how a speakers impedence is only based on an average, as the speaker moves it creates more resistance therefore bringing it up to somewhere around 8 ohms. Just thought I'd add that
 
and to put it simpler incase ya need...

basically 8 ohms on the amp, and 6 ohms on the speaker, means the amp gets extra power - taking a bit away from the speaker.

when they are matched, the power is dispersed 50/50 between the 2. thus, you are putting extra strain on your amp with a lower impedence rating on your speakers.
 
shackrock said:
and to put it simpler incase ya need...

basically 8 ohms on the amp, and 6 ohms on the speaker, means the amp gets extra power - taking a bit away from the speaker.

when they are matched, the power is dispersed 50/50 between the 2. thus, you are putting extra strain on your amp with a lower impedence rating on your speakers.
What?

The amp output isn't 8 ohms, it is expecting to see 8 ohms. The amp doesn't get extra power, it puts out extra power with a smaller load.

If two cabinets on the same amp are matched, The power is dispersed equally. If you have mismatched cabinets (more than one) the cabinet with the lower impedance will draw the most power.


If this is a tube amp, You should not run a cabinet that is lower impedance that the output is disigned for. (higher impedance won't hurt anything)

If it is a solid state amp, you will probably be fine.
 
Farview said:
What?

The amp output isn't 8 ohms, it is expecting to see 8 ohms. The amp doesn't get extra power, it puts out extra power with a smaller load.

If two cabinets on the same amp are matched, The power is dispersed equally. If you have mismatched cabinets (more than one) the cabinet with the lower impedance will draw the most power.


If this is a tube amp, You should not run a cabinet that is lower impedance that the output is disigned for. (higher impedance won't hurt anything)

If it is a solid state amp, you will probably be fine.

Good post. Another voice of reason.

The "simple" explanations are seeming to complicate things more!
 
BTW. A 6 ohm speaker is kind of a strange thing to find. How do you know it's 6 ohms?
 
I guess this would be a good time to say that im not speaking of a guitar amp. Im talking about a stereo. THe receiver's amp handles 8 ohms per speaker. I have 2 6 ohm speakers. I was wondering if it is ok to hook them up to the receiver without causing any type of damage. It seems to me that the question is still unanswered..I hope this can clear up the division of opinions.
 
You should be OK as long as it isn't a tube amp. (yes, there are tube stereos)
 
Farview said:
What?

The amp output isn't 8 ohms, it is expecting to see 8 ohms. The amp doesn't get extra power, it puts out extra power with a smaller load.

If two cabinets on the same amp are matched, The power is dispersed equally. If you have mismatched cabinets (more than one) the cabinet with the lower impedance will draw the most power.


If this is a tube amp, You should not run a cabinet that is lower impedance that the output is disigned for. (higher impedance won't hurt anything)

If it is a solid state amp, you will probably be fine.


while that's true farview...i am trying to let him picture it like this (see attached gif....ha)

would you say that's not a decent way to view it simply (a thevinens EQ circuit for the amp, and the load)?
 

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It just gives the impression that it works differently than it does. The idea is that you are supposed to match the impedance the output is rated at with the speaker load. You gave the wrong reason why you have to do that. And that whole thing about the power being distributed 50/50 between the amp and the speaker is really confusing. The amp is providing the power to the speaker. If the power is being disbursed between the amp and the speaker, it would need to be coming from somewhere else. That doesn' make any sense.
 
feel the HEAT

Excuse , my lamens "take" on the Ohms being reduced..
but isn't it basic Ohms law...V= IxR??
so if R(resistance=ohms) reduces, I (current=amps) must go up.

Current/Amps increasing causes the HEAT which burns out the power amplifier in most cases.

so worse yet, hooking up a 4 ohm to a designed 8ohm amplifier power section, the amplifier output chip, (or transistor or tube,) would get even hotter than the 6ohm.......due to the increased current/amps being pulled.

8ohm is the designed match...use 8 ohm.

You ever physically touched a output amp chip or a CPU chip???..freaking, hot little fucking things...sizzling hot...and thats when their by design! let alone you go messing with the setup, using 6 ohm or 4 ohm on a 8ohm design.

also what happens when you rub something really fast..HEAT...this is a friction of mass, electron ion movement...material types induced, realese and expansion,contraction.. blah,blahblah....who cares...

HEAT is the enemy of all electronics.... and going 6ohm your adding more heat. Generally the power amps fry, but sometimes the fried power amp will send a distorted flat line to your driver and fry it out.

Put some FUSES in line......there's your basic insurance.

Why are you using 6ohm on a 8ohm anyway??
 
Shout It Out said:
It seems to me that the question is still unanswered.
Do you want me to answer it a second time?

NO.

And when you ask again the third time you can use this:

NO.

G.
 
COOLCAT said:
Excuse , my lamens "take" on the Ohms being reduced..
but isn't it basic Ohms law...V= IxR??
so if R(resistance=ohms) reduces, I (current=amps) must go up.
HEAT is the enemy of all electronics.... and going 6ohm your adding more heat. Generally the power amps fry, but sometimes the fried power amp will send a distorted flat line to your driver and fry it out.

Put some FUSES in line......there's your basic insurance.

He speaketh the truth! Good thread too!

Glen, thanks for the compression tutorial.
 
shackrock said:
while that's true farview...i am trying to let him picture it like this (see attached gif....ha)

would you say that's not a decent way to view it simply (a thevinens EQ circuit for the amp, and the load)?

The diagram is ok. Your understanding of it, amps, and Thevenin diagrams need a bit of work, though. :p
 
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