Strange xover (?)

[Gluca]

I bought a pair of used Fostex T945's (they are in great conditions! lovely) to cover the hi-end. For the time being I am using them with my full range by Ciare. There is no xover, just a 2uF series cap to cut the tweeter. The cap is OK (it is not leaky and it measured in excess of 15MOhm).

I noticed a small hum coming out of the tweeter and that was weird to me. After a few checks and inspections, I wired the signal generator onto the amp spanning from 20Hz up to 20kHz and ... oh! ... the tweeter was sounding even at those (very) low freqs. Let me say that cap is not hi-passing anything. Wirings seem OK.

I was not expecting to hear anything at that freqs. Odd!

Any hint? Should I check something else? I am not so happy to feed the tweeter with low freqs.

Ciao
Gianluca

 

[lndm]

I have found that tweeters are surprisingly good at producing bass. Assuming that nothing's broken, I would consider finding an inductor to put across the tweeter. One for example that resonates with the cap at a decade below the xover frequency. I doubt you'd notice it there.

 

[Gluca]

You mean going for a 2nd order xover? Now the cap is cutting at -6db/oct up to 10kHz (or something very close to 10kHz)... that means a 50Hz tone should be attenuated by 35-40db at the tweeter ... It doesnt seem so now.

Ciao
Gianluca