tweeter protection

[diviy]

After blowing one of my tweeters on my kef q15 I failed to get one anywhere and I will not pay kef a 100 quid for a new pair.
so found a mint set of q35's for a bargin price plus I found some cracking lp's in Vinyl Vault in Cheltenham and some new lp's in Rise.
I blew the tweeter after running my system at full blast (i was having a really bad day):( I was using the A65 and one Alphap8 then
I am now running a A65 as a pre amp and two Alpha p8's as mono block's is there any way of protecting the tweeters
apart from running at full volume I've seen the bulb idea but anyone got any suggestions of how I can protect them ?

[dantheman91]

After blowing one of my tweeters on my kef q15 I failed to get one anywhere and I will not pay kef a 100 quid for a new pair.
so found a mint set of q35's for a bargin price plus I found some cracking lp's in Vinyl Vault in Cheltenham and some new lp's in Rise.
I blew the tweeter after running my system at full blast (i was having a really bad day):( I was using the A65 and one Alphap8 then
I am now running a A65 as a pre amp and two Alpha p8's as mono block's is there any way of protecting the tweeters
apart from running at full volume I've seen the bulb idea but anyone got any suggestions of how I can protect them ?

Hi Gerald,

I personally think that kefs are not really designed to be played VERY loud. It could be your amplifiers clipping as a result of the blow second tweeters. no expert but i would look at the amps to see if something sinister is causing this their must be something.:scratch:

[diviy]

could be your amplifiers clipping as a result of the blow second*tweeters


Sorry you have lost me

[walpurgis]

And me. :scratch:

[spendorman]

What capacitors feed the tweeter, if they are old reversible electrolytics, this does not help?

I believe that plenty of KEF T27 in classic KEF's are blown this way.

[diviy]

So you think its worth changing the capacitors
On the crossovers ?

[dantheman91]

Talking rubbish as usual..........:rolleyes:

Sorry............

[spendorman]

I'm a bit lost here!

Yes, old rev electrolytic capacitors could result in blown tweeters, so could a clipping amp.

[Reffc]

There's several things going on here which are contributing to failed tweeters: possible amp clipping; putting too much power through the tweeters; out of spec electrolytics. The latter may shift crossover point but are unlikely to fail short circuit so its not always likely that old caps are responsible. Old electrolytics sometimes measure ok for capacitance but they wont be ok for equivalent series resistance which increases generally with age. If the crossover point is already quite low (ie under 2500 Hz), this increased ESR has the effect of lowering crossover point for any given capacitance value, so the effect of lowering the crossover (besides significant increased distortion if lying within an octave and a half of tweeter resonance) is to put too much power through it. Decreased power handling + "a bad day" (volume set at "11" :eek:) can = blown tweeter.

To play safe...replace HF caps with LIKE for LIKE new caps and keep volume moderate unless it is a high power handling speaker system (good advice for most speakers).

If changing tweeters for something different, you will most likely need a redesign of HF crossover filter.