4 ohms or 8 ohms setting?

[S83 Trike]

My amp has both 4 ohm and 8 ohm speaker connections at the rear of the Icon.

My speakers are 8ohm ATC 11 - can I use the 4ohm connections, what would happen?

 

[macdiddy]

damage your amp or speakers or possibly both.

unless you want to find out just stick to the 8 ohm connections.

someone else may come along with a scientific reason why.

 

[davedotco]

Valves have an inherently high output impedence so to drive the relatively low impedance of any speaker, a transformer is used to 'match' the impedance of the valve to that of the speaker.

This optimises power output and 'effective' output impedance. In this case using the 4 ohm terminals will probably lead to a slight reduction in power output and possibly a better damping factor.

Very small differences though, you would almost certainly not blow anything up if you were to try both.

 

[Vladimir]

The speakers would suck up more juice out of the amp, which will make it work harder.

Those ATCs can eat a 300Wpc amp for breakfast. The Icon ST40 only tickles them.

 

[Al ears]

The speakers would suck up more juice out of the amp, which will make it work harder.

Those ATCs can eat a 300Wpc amp for breakfast. The Icon ST40 only tickles them.

Quite agree. These speakers are not ideal for your amp, but using 4ohm connection is unlikely to damage either.

The amp could benefit from a change of speaker though.

 

[The_Lhc]

My amp has both 4 ohm and 8 ohm speaker connections at the rear of the Icon.

My speakers are 8ohm ATC 11 - can I use the 4ohm connections, what would happen?

If you have 8ohm speakers why would you want to use the 4ohm connection?

 

[Infiniteloop]

My amp has both 4 ohm and 8 ohm speaker connections at the rear of the Icon.

My speakers are 8ohm ATC 11 - can I use the 4ohm connections, what would happen?

If you have 8ohm speakers why would you want to use the 4ohm connection?

I have used 8 Ohm speakers on a 4 Ohm tap before, because to my ears, they sounded better that way.

 

[Al ears]

My amp has both 4 ohm and 8 ohm speaker connections at the rear of the Icon.

My speakers are 8ohm ATC 11 - can I use the 4ohm connections, what would happen?

If you have 8ohm speakers why would you want to use the 4ohm connection?

I have used 8 Ohm speakers on a 4 Ohm tap before, because to my ears, they sounded better that way.

Some speakers are nominally rated as 8ohm but in practice often dip way below this and are sometimes best run on a 4 ohm setting. Whichever, the 85 dB SCM 11s are not ideal for valve amps if you want to get the best out of them.

 

[davedotco]

My amp has both 4 ohm and 8 ohm speaker connections at the rear of the Icon.

My speakers are 8ohm ATC 11 - can I use the 4ohm connections, what would happen?

If you have 8ohm speakers why would you want to use the 4ohm connection?

I have used 8 Ohm speakers on a 4 Ohm tap before, because to my ears, they sounded better that way.

You will have changed the output impedance of the amplifier which may affect both frquency response and dampling factor.

The effect may (or may not) by audible and you may prefer the results with the 'wrong' connections.

Thats hi-fi...*unknw*