Mordant-short MS500 help - UK Vintage Radio Repair and Restoration Discussion Forum

jobsworth · 23rd Sep 2022, 10:32 am

Hi there! I have been gifted a pair of Mordaunt-Short MS500 speakers - I would imagine they are from the late 1960s or early 1970s. Build quality is excellent and they are huge and weigh a ton! They feature a 12” bass unit and the Decca Kelly ribbon tweeters. I cannot find anything about them online- plenty of information on the more recent MS500 gold and the MS400 of the same era. I was wondering if anyone has any information on these speakers - so specifications and power handling etc. I have wired them up and they seem to work with a very rich bass. Any help gratefully received!👍

Ted Kendall · 23rd Sep 2022, 11:05 am

I take it the "rich bass" isn't merely the result of the tweeters not working? The Decca ribbons were rated at 30W - the treble component of a 30W signal, of course! - so should be OK at reasonable listening levels. Historically, the mating of a large bass unit with a ribbon tended to risk a "hole in the middle" where the bass cone was breaking up and the tweeter had little power - Peter Walker cited this as the major weakness of his Corner Ribbon, which preceded the ESL57. That said, if they sound good to you, job done!

jobsworth · 23rd Sep 2022, 11:18 am

Hi Ted! Thanks for your response. The tweeters seem to be functioning in that there is sound coming from them so I assume they are working correctly. The bass units are Celestion. I will continue my experiments but knowing that the tweeter is a 30 watt unit is very helpful. Regards Chris F

23rd Sep 2022, 10:32 am	#1
jobsworth Tetrode Join Date: Apr 2010 Location: Croydon, London, UK. Posts: 69	Mordant-short MS500 help Hi there! I have been gifted a pair of Mordaunt-Short MS500 speakers - I would imagine they are from the late 1960s or early 1970s. Build quality is excellent and they are huge and weigh a ton! They feature a 12” bass unit and the Decca Kelly ribbon tweeters. I cannot find anything about them online- plenty of information on the more recent MS500 gold and the MS400 of the same era. I was wondering if anyone has any information on these speakers - so specifications and power handling etc. I have wired them up and they seem to work with a very rich bass. Any help gratefully received!👍

23rd Sep 2022, 11:05 am	#2
Ted Kendall Dekatron Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 3,675	Re: Mordant-short MS500 help I take it the "rich bass" isn't merely the result of the tweeters not working? The Decca ribbons were rated at 30W - the treble component of a 30W signal, of course! - so should be OK at reasonable listening levels. Historically, the mating of a large bass unit with a ribbon tended to risk a "hole in the middle" where the bass cone was breaking up and the tweeter had little power - Peter Walker cited this as the major weakness of his Corner Ribbon, which preceded the ESL57. That said, if they sound good to you, job done!

23rd Sep 2022, 11:18 am	#3
jobsworth Tetrode Join Date: Apr 2010 Location: Croydon, London, UK. Posts: 69	Re: Mordant-short MS500 help Hi Ted! Thanks for your response. The tweeters seem to be functioning in that there is sound coming from them so I assume they are working correctly. The bass units are Celestion. I will continue my experiments but knowing that the tweeter is a 30 watt unit is very helpful. Regards Chris F