Is better use 8ohms OPT with 8ohms speakers to 4ohms tap with 4ohms speakers ?

[santitrucco]

Is better use 8 Ohms OPT with 8 Ohms speakers, to 4 Ohms tap with 4 Ohms speakers ?

Or are different performances.

 

[JonSnell Electronic]

Either. If you have a 4 Ohm speaker use the 4 Ohm tap. If you have an 8 Ohm speaker use the 8 Ohm tap.

 

[coolcity]

Except when it's an exception and the reverse is true. I really agree with JonSnell for most typical pairings, but sometimes the speaker will have load aberrations that may require using a higher or lower tap than usual. Having an accurate impedance/phase graph is sometimes helpful in making your first choice. Sometimes personal preference of the sound may affect one's settings. Confusing? Like many aspects of audio.

 

[Burnedfingers]

The nominal impedance varies with frequency. The (8) or (4) ohm rating is nothing more than an average of the impedance across the frequency band. Therefore some speakers that are rated at 8 ohms actually sound better across the 4 ohm tap of tube amplifiers.

 

[santitrucco]

I think that the 4 ohms speakers, have a good flat impedance response.
I will try it.