Speakers with different ohm

[Wookson]

I have been upgrading my speakers from my 7.2 setup.

My old speakers where 6ohm speakers.

Now, i bought 2 new front speakers and a new center speaker. They are 4ohm.
Which ohm setting do i need to use now on my avr?

Greetings, David

 

[voodooless]

What AVR?

Usually this kind of a setting is only there for regulatory reasons. In most cases you can leave it in the highest impedance setting to extract the most power out of it. Make sure you have decent ventilation to get rid of the heat!

 

[DVDdoug]

Make sure the AVR is rated for 4-Ohms. Lower impedance puts more "stress" on the amplifier. (Higher impedance is always OK.)

It MIGHT be OK if you don't push it to maximum loudness and/or it might go into thermal protection and safely shut-down if it overheats, but there's a chance of the AVR being damaged so I'd say "not recommended" if the AVR isn't rated for 4-Ohms


-----
Some technical background if you want it -
Impedance and resistance (both Ohms) are "the resistance to current flow". With the same voltage you get more current (and more power) with lower impedance and amplifiers "try" to put out voltage that's independent of the load.

If the amplifier can-put out the same voltage (and double the current) you'll get twice the current and twice the wattage with 4-Ohms compared to 8-Ohms.

It's OK if it's "current starved" and can't put-the same voltage, as long as it's rated for the lower impedance.

A 100W light bulb has lower resistance than a 60W bulb. If you connect too many lights you get excess current and the circuit breaker will blow. With nothing plugged-in (or with the light turned-off) you have infinite resistance and no current flows. The voltage is still present.

 

[voodooless]

I think basically every AVR will be fine with 4 Ohm speakers nowadays, even if it’s not explicitly specified.

4 Ohm is so common that they cannot afford to get broken products due to the amps not being able to handle them.

 

[Wookson]

My avr is a Marantz cinema 50, but it is coupled to a Emotiva bas x 3 that drives my fronts and center
Both the avr and poweramp can handle 4 ohm, just as my new front and center speakers.

Its just the surround speakers that are 6 ohm

 

[voodooless]

My avr is a Marantz cinema 50, but it is coupled to a Emotiva bas x 3 that drives my fronts and center
Both the avr and poweramp can handle 4 ohm, just as my new front and center speakers.

Then you are perfectly fine. Given that you use an external amp, the AVR impedance setting will have zero effect on those channels anyway.

Its just the surround speakers that are 6 ohm

That doesn’t matter. Just leave the setting at 8 Ohm.

 

[Wookson]

So i just put my avr to 8ohm then, the poweramp doesnt have a separate setting?

 

[Wookson]

Wouldnt the fronts and center be more dynamic on 4ohm?

 

[voodooless]

So i just put my avr to 8ohm then, the poweramp doesnt have a separate setting?

Yup. The Emotiva doesn’t have any settings whatsoever.

 

[voodooless]

Wouldnt the fronts and center be more dynamic on 4ohm?

No. The setting in the AVR has no influence on external amps.

 

[kyuu]

Wouldnt the fronts and center be more dynamic on 4ohm?

As stated, with external amps the setting is irrelevant. Even if you were using the AVR's amps, changing the setting to 4ohm just results in a significant reduction in maximum power. There's basically no reason to ever use that setting in practical usage, regardless of what speaker you're using.