Matching impedance between speakers to amp .

[ISAC69]

Hi

My Proac 140 MK2 impedance is nominal 4 Ohm minimum 3.2 Ohm , I want to match a power amp Rotel RB 1582 that specified as min. 4 Ohm .

Might this match be unsuitable ? Might it damage the amp or the speakers ?

 

[Benedict_Arnold]

Probably not.

The impedance of speakers goes up and down with the frequency of the signal being put through them. Speaking testically for a moment, it's due to what is known as the reluctance of the coils. Beyond that you get into complex number theory and it's far too late at night for me to get into that.

FWIW I drove a pair of ProAc Studio 140 Mark 1 with twin Cyrus X-powers, no problem.

Power transfer theory also says the impedance of the load (speakers) should be equal to the impedance of the power supply (amp), but again that gets highly testical and it's 3 am here in Houston....

 

[tomlinscote]

I would not have thought that if the min value is 3.2 the amp could cope with the drop in impedance it may get a bit warm if you drive it at high levels for a long time and most decent amps will just shut off the output stage if they get too warm to prevent damage. But then again its not my kit!

Tommo