connecting 8 ohm tweeter to 300b pse

[Princo]

My 300b pse output transformers are 8 ohm, driving FR 8 ohm speakers, connecting 8 ohm tweeters in parallel will reduce combined impedance to 4 ohm, will this be a problem for the amps

thanks

[John Caswell]

First question, is why do you want to do this as your L/S are full range?
Answer - no I doubt if it will affect the amplifier if you just connect it hup to test them.
You must feed the tweeter via a capacitor of suitable value - start off with a 2µF 50v and go from there, you may also find that you have to reduce the output of the tweeter with a suitable series resistor start at 1R and go from there.
A spectrum analyser is a great help here, and you can get a reasonable free one for the iPad.
You are now getting into an area that is very subjective.

John

[Princo]

They are full range in name but drop off quite rapidly above 11k.

I will be using an active filter and separate amp for the tweeters in future, i just wanted to try the tweeters now, i already put a 2.2uf cap on the tweeter +ve, so just wondered if i would stress the 300b by driving 4ohm instead of 8ohm in the meantime

Thanks

[John Caswell]

At normal listening levels there should not be a problem. At high ear shattering levels, yes the o/p stage may not like it. Care required.

John

[Princo]

Thanks John