4 ohm and fried

[ecc83]

"Once Upon a Time" There were only valved amplifiers.

Nobody cared much about power ratings. A 6v6 or later a UL84 gave you more than enough wick from a radio. 2x EL84/6V6 was plenty for hi fi, movie projector or bingo calling. Flip me! the local ABC cinema only used a single 20W KT66 amp to drive the screen speaker (but that was admittedly the size of a small brick SH!). Then came the Transistor* and Music Power and Peak power and STILL we are left with that mathematical absurdity "rms" watts!

But even with the best of intentions, amp makers have a hard job specifying power output. Virtually no vlave amps have stabilized power supplies and very few solid state ones. This means that the power delivery can only be specified at nominal mains, 230volts rms here. At 10% above or below the power will be more or less but since you would have to DOUBLE the power level to cause just a 3dB SPL increase I think we can ignore the vaguaries of manins voltage?

And yes, a theoretically "perfect" power amp with an infinitely small output resistance and a stabilized power supply of sufficient current capacity WOULD double its power output as Z fell by half and we have seen that some of the real biggies aproach this but not quite.

*And this gave rise to the STUPIDEST invention of all time. The EIGHT OHM headphone!

Dave.

 

[resin8r]

What was the topic? ... Oh yeah, speakers. Remove the woofer and tweeter and check the voice coils at the terminals with an ohm meter.
If the coils are good you can replace the foam. There are various sellers online and ebay that sell them as well as Parts Express, etc. Just google "speaker foam repair kit". The trick will be finding one that matches your speakers. There may be a generic that fits or you may have to get one specific to that speaker. I don't know what tweeters are in there or if the have replaceable diaphragms, but those or a replacement tweeter should be available on line as well. You should be able to refurb them for less than $100 if the woofer coil is intact.

 

[Farview]

Underpowering speakers will tend to blow tweeters more than anything else. this is because the square wave from a clipping amp creates a lot of high frequency energy that gets directed to the tweeter and overpowers it, and burns it up. So sending a speaker not enough power does not blow speakers, accident creating a situation that sends too much signal to a driver that can't handle it does.