amp destroying speakers

[JazzNote]

My AI Clarus 2R broke down today and most probably destroyed the Eminence Beta 10 cx in my Stealth 10 cabinet and a speaker in my friends Eden cabinet. First it blew mine and when we wanted to check if the lack of sound was due to speaker failure and plugged into my friend's cabinet it blew that one too
We tried both cabinets with another amp and they only provided sound of very low volume which was heavily distorted. (about 1% of the normal volume)

- question: is the damage in the speaker measurable with a resistance meter?
- question: does anyone know how a amp can destroy a speaker?
- what replacement speaker would be recommended for the Eminence Beta 10 cx in my stealth 10 ?

Thanks

[Jabberwocky]

https://www.parts-express.com/eminen...river--290-502

[customxke]

An amp can destroy a speaker if it puts out DC current.

[aquin43]

At a guess, the amp may have failed so that it is producing dc across the speaker terminals. This would overheat the speaker voice coil and burn the insulation on the coil wire. The speaker can't be completely burnt out or it would produce no sound at all. A speaker usually has a resistance slightly below its rated impedance. ~6 Ohms for 8 and ~3.5 Ohms for 4. If the coil has not burned out, the resistance measurement will appear OK but the voice coil may be deformed and have shorted or loose turns. This would cause scraping in the magnet gap. Pushing the cone gently in and out should reveal this.

Class D power amps are usually quite elaborate circuits that sense this sort of fault and switch off to protect the speaker.

[JazzNote]

Thanks for the answers so far!
Still curious abot what kind of defect would cause the amp to put out DC current?

[icr]

Thanks for the answers so far!
Still curious abot what kind of defect would cause the amp to put out DC current?

With respect to transistor Hi-Fi amps, semiconductor failures are the most common, and probably the same for transistorized guitar amps. In this non-unnusual situation, transistor Q1 is shorted and that is temporarily putting 47.5 volts DC on the speaker lead.

[JazzNote]

https://www.parts-express.com/eminen...river--290-502

Great company to deal with. Easy ordering process & fast delivery. Now my Stealth 10 is doing fine again, thanks for the link!

[sgosnell]

Great company to deal with. Easy ordering process & fast delivery. Now my Stealth 10 is doing fine again, thanks for the link!

Parts Express is indeed a great company to deal with. Their house brand electronics (Dayton Audio) is good quality, and if there is ever a problem, they make it right. Customer service is as good as I've seen anywhere.