Speakers 300b amp

[snodge]

Hi I have some Lii Audio F15 full range speakers that I will try with the 300b amp. I have been advised that I should try a speaker with a flat impedance load. I don't actually know what this means?

https://www.lii-audio.com/product/re...-f-15-in-pair/

The specs for the drivers is given in the link above.

Many thanks. David

[Richard]

Hi, Re (DCR) is given as 6.56 Ohms so it's most likely an 8 Ohm nominal drive unit.

The cabinet and type of loading though will determine the speaker impedance which changes with frequency.

This is usually shown as a line on a graph where the X axis is frequency and Y is Ohms. The ideal might be a straight line from 20Hz to 20KHz at 8 Ohms but in reality it may be higher at the ends with a hump and dip at bass resonance. This dip, often down to a couple of Ohms, can cause lumpy/weak bass sound if the amplifier cannot drive it fully.

For an 8 Ohm valve amp with little feedback you are best with speakers which don't dip below about 4 Ohms but try amps and speakers together as they often sound better than expected.

[snodge]

Hi Richard, I have them so will try them and see what they sound like. Thanks for the response. Best wishes David