This question is aimed to TRUE Elec Engineers, not fuse or wire directionality believers.

I did that with 25 amps ssr and it works great. No sound changes at all 

@ssg308, can u pls tell me the EXACT model/make of the device u used ?  Also, the KEY is, would it work/disengage in case of a DC fault ?
Thanks

@ssg308, since some SSRs internally use back to back SCRs or triacs, they may NOT turn off when the trigger is removed and DC is flowing, which would destroy the speaker in a second under fault conditions.

Thanks

Hi Cakyol

Darn, a legitimate question on this forum.  Ok, I'm a real EE.  I'm not aware of a high failure rate in amplifiers, but perhaps just that...unaware.  Are you concerned with a specific aspect of your system that you want to protect your speakers with something faster than a fast acting fuse?  I admit to not having used an SSR in your application, but like you, would be curious about any acoustic artifacts associated with putting even a low impedance semiconductor in series with the speaker wiring.  On the other hand, as infrequently as a mechanical relay would be switched hot, i.e., under heavy load, I wouldn't have any concerns about contact erosion or wear for one with contacts that are properly sized.  Also, I'm curious what you were going to use as a derived control signal for the relay of your choice.

Keep us posted on your progress and results!