Speaker dust shrouds. - UK Vintage Radio Repair and Restoration Discussion Forum

Biggles · 11th Nov 2018, 10:10 pm

Having worked on some quite old sets in the past, I was just wondering at what point they stopped using those cloth "bags" around the speaker. Was there a reason for them to be used such as the earlier speakers were more susceptible to dust than later designs, or were they expecting houses to be dustier in the old days or was it merely an acoustical thing? You never see them used on later sets.
Alan.

electrogram · 11th Nov 2018, 10:34 pm

Could be that in later speakers the voice coil and the gap it moves in are completly sealed from the outside world by a dust cap on the front and suspension behind, whereas early speakers usually had a suspension 'spider' which did not seal

Boater Sam · 11th Nov 2018, 10:46 pm

They disappeared when speakers ceased to be capable of being taken apart easily with glued dust caps and sealed cone centre suspensions.

John10b · 12th Nov 2018, 7:52 pm

Interesting question, I had never really thought about it.
My only comment would be that houses in the past certainly had a lot more dust (coal dust in particular) flying about, certainly in our house. So I suppose they could have been used to stop the speakers becoming contaminated.
Cheers
John

McMurdo · 12th Nov 2018, 8:59 pm

I pondered about it when watching a youtube clip of a 1930's radio factory where the women were putting the bags on the speakers. I quite like them. I also put it down to the open nature of those 30's/40's speakers. They're certainly dusty when you take them off!

m0cemdave · 13th Nov 2018, 8:14 pm

I think Boater Sam has the answer.

Open spiders were more susceptible to dust and filings collecting in the gap then the glued-in pleated suspensions that replaced them.

Biggles · 14th Nov 2018, 12:13 am

I agree, it seems a sensible explanation. Obviously speaker manufacturing technology has moved on and made the use of shrouds obsolete. I was just trying to remember what year was about the latest I have seen them fitted, but maybe some manufacturers used them for longer than others, depending on how up to date their production lines were.
Alan.

11th Nov 2018, 10:10 pm	#1
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Speaker dust shrouds. Having worked on some quite old sets in the past, I was just wondering at what point they stopped using those cloth "bags" around the speaker. Was there a reason for them to be used such as the earlier speakers were more susceptible to dust than later designs, or were they expecting houses to be dustier in the old days or was it merely an acoustical thing? You never see them used on later sets. Alan.

11th Nov 2018, 10:34 pm	#2
electrogram Heptode Join Date: Jul 2008 Location: Hereford, UK. Posts: 719	Re: Speaker dust shrouds. Could be that in later speakers the voice coil and the gap it moves in are completly sealed from the outside world by a dust cap on the front and suspension behind, whereas early speakers usually had a suspension 'spider' which did not seal

11th Nov 2018, 10:46 pm	#3
Boater Sam Banned Join Date: Dec 2013 Location: Middlewich, Cheshire, UK. & Winter in the Philippines. Posts: 3,897	Re: Speaker dust shrouds. They disappeared when speakers ceased to be capable of being taken apart easily with glued dust caps and sealed cone centre suspensions.

12th Nov 2018, 7:52 pm	#4
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,882	Re: Speaker dust shrouds. Interesting question, I had never really thought about it. My only comment would be that houses in the past certainly had a lot more dust (coal dust in particular) flying about, certainly in our house. So I suppose they could have been used to stop the speakers becoming contaminated. Cheers John

12th Nov 2018, 8:59 pm	#5
McMurdo Dekatron Join Date: Jun 2009 Location: Staffordshire Moorlands, UK. Posts: 5,269	Re: Speaker dust shrouds. I pondered about it when watching a youtube clip of a 1930's radio factory where the women were putting the bags on the speakers. I quite like them. I also put it down to the open nature of those 30's/40's speakers. They're certainly dusty when you take them off! __________________ Kevin

13th Nov 2018, 8:14 pm	#6
m0cemdave Octode Join Date: Feb 2009 Location: Bletchley, Buckinghamshire, UK. Posts: 1,219	Re: Speaker dust shrouds. I think Boater Sam has the answer. Open spiders were more susceptible to dust and filings collecting in the gap then the glued-in pleated suspensions that replaced them.

14th Nov 2018, 12:13 am	#7
Biggles Rest in Peace Join Date: Feb 2004 Location: Hexham, Northumberland, UK. Posts: 2,234	Re: Speaker dust shrouds. I agree, it seems a sensible explanation. Obviously speaker manufacturing technology has moved on and made the use of shrouds obsolete. I was just trying to remember what year was about the latest I have seen them fitted, but maybe some manufacturers used them for longer than others, depending on how up to date their production lines were. Alan.