Thiel CS 3.6 mid-range problem

Are you powering your equipment on and off in the proper sequence? Meaning power amp on last and off first? And when you turn the power amp off, are you waiting long enough before turning off the upstream components to assure that the amp is no longer being kept "alive" by energy stored in its power supply capacitors, so that it can no longer amplify turn-off transients that may be generated upstream? That can take as much as a minute or so with some of the solid state amps that I have experience with.

Regards,
-- Al

Al, thanks very much for your advice. No, I haven't but I will start now! Question: should I power off the amp and then wait at least a minute before powering off the upstream components? Glenn

Hi Glenn,

Yes, I would strongly recommend doing that. The one minute figure, though, was just a guess based on my experience with other high powered solid state amps. I suppose that a good way of determining how much time to allow would be to play some music at a VERY low volume level, then turn off the amp and see how long the music continues to play for. It would probably be a good idea to make that determination for going into standby mode as well as for going into "off" mode.

What makes all of this particularly important with your equipment is that your amp is capable of delivering enormous amounts of power (in the vicinity of 1000 watts) into the 2.5 to 3 ohm impedance the speakers have throughout the mid-range region. So even a very brief turn-off transient from the upstream components, applied to the input of the amp while it is still powered up internally, could very conceivably put your speakers in jeopardy.

Best regards,
-- Al

Al,

Once again, I appreciate your interest and advice. You're obviously an expert. In this case, the black wire connecting to the mid-range is the problem. When I removed the mid-range, I observed that the "black connector" on the back of the driver had about 1/4 inch of copper wire still soldered to it. The black rubber-coated copper wire leading from the speaker cabinet to the mid-range was intact, but was detached from the 1/4 inch wire attached to the driver. Inotherwords, I wonder if too much power (or something else) could overheat a wire causing it to split in two. Sounds far-fetched, but I don't know what would make that happen. Thank you again for sharing your knowledge! Glenn

I am interested in a used set of Thiel CS 3.6's and I was talking to the lady at Theil today (Dawn) and she warned that the midranges on these speakers are susceptible to blow if you try to use them with high powered home theater use. You aren't trying to recreate movie sound effects with these speakers are you?You can contact the company and they can either re-build the midranges or they may be able to sell you a replacement driver.