TDC was a Tech Hi-Fi house brand manufactured by AAL in Chicago. AAL eventually became MTX.
Need Help on TDC Speakers
I have in my possession two main speakers. They are quite large each speaker has two 10" woofers, two 4 1/2" mids, and two tweeters. The only label on them shows them to be manufactured in Massachusets and it states "TDC-20". In the research I've done I discovered they may be proto-type speakers from the late 70's or early 80's and they may have some link to the Tannoy company. Please help me identify and possible assign a value to them. Thank You.