|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
21st Feb 2020, 4:37 pm | #1 |
Hexode
Join Date: Sep 2005
Location: Potton, Bedfordshire, UK.
Posts: 293
|
Vintage radio loudspeaker dust bag
Hi folks,
Not sure if I have described this properly but speakers used to be enclosed in a cloth bag to keep the dust out. The bag enclosed the whole of the speaker and was tied around the magnet with thin cord or string. I'm have an 8 inch extension speaker where the bag has decayed into a very fragile state and has been torn on the front where fingers have been poked through the fret so can anyone recommend a source of these please. Alf |
21st Feb 2020, 4:43 pm | #2 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,970
|
Re: Vintage radio loudspeaker dust bag
Philips were very keen on these.
You don't really need them in a modern domestic environment, though you could easily make one with some acoustically transparent fabric. Time to get out the sewing machine! A fabric peg bag (for clothes pegs) might be suitable. |
21st Feb 2020, 5:12 pm | #3 | |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,725
|
Re: Vintage radio loudspeaker dust bag
Quote:
Military boat-anchors too. I'm sure my R107 had a bag with a draw-string.
__________________
-- Graham. G3ZVT |
|
21st Feb 2020, 5:17 pm | #4 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,970
|
Re: Vintage radio loudspeaker dust bag
It does make sense to do it if the speaker is to be used in a hostile environment, as you don't want large particles lodging in the voice coil. A typical modern house won't have an open coal fire or smoking occupants though - most dust will be tiny dead skin particles which aren't abrasive.
|
21st Feb 2020, 5:43 pm | #5 |
Heptode
Join Date: Jul 2012
Location: Derby DE1, Derbyshire, UK.
Posts: 626
|
Re: Vintage radio loudspeaker dust bag
Hi Alf,
I remember making one of these many years ago out of some thin cloth, worked great i drew round a cercular dinner plate with a pen, and had a bit of help from a family member to sew it up on the sewing machine. As paul said an old peg bag would be ideal, i used a long black boot lace to tie the finished bag arround the magnet. If you have a short off cut of a piece of net curtain wire, you can use that with the boot lace or string, attached to the end of it to help thread the lace or tie through the hem for tieing. The curtain wire can then be disgarded once the lace or tie is threaded through the hem, and then the lace will act as a draw string to tighten the finished cover arround the speaker magnet. Paul |
21st Feb 2020, 6:03 pm | #6 |
Dekatron
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
|
Re: Vintage radio loudspeaker dust bag
Later speakers have dust caps that prevent dust entering the gap around the voice coil. Early speakers were often open and there are plenty of threads here discussing how to remove the accumulated dirt and dust,
|
21st Feb 2020, 7:44 pm | #7 |
Rest in Peace
Join Date: Mar 2011
Location: Basildon, Essex, UK.
Posts: 4,100
|
Re: Vintage radio loudspeaker dust bag
A modern home with pets will have an enormous amount of dust and hair floating around. We have to empty out the "hoover" at least once a week, it is always full of hair and dust. Curtains, clothing, skin, furnishings, hair, I would imagine there is more around now than in the old days when rooms were more spartan.
As the speaker moves, dust can be drawn in and out of the speech coil gap. So I consider a dust bag is always a good idea if the voice coil is open to the atmosphere. Even more so if you put the speaker down on a bench where their may be a speck of rust or iron filing. Mike |
21st Feb 2020, 8:00 pm | #8 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,010
|
Re: Vintage radio loudspeaker dust bag
Having lived for decades in seriously-dusty/furry environments [a couple of 110-pound dogs throw off lots of fur and dander] I've never found the need for 'dust-bags' on any of my speakers.
Turn it up! [I can't hear the guitar] . . . . |
22nd Feb 2020, 12:29 am | #9 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,554
|
Re: Vintage radio loudspeaker dust bag
A Numatic motor filter for a Henry cleaner would be a good thing if you are prepared to put up with it being white.
They are round and are also about the right size (the same diameter as the cleaner body) and are still made and sold as a spare part. They are made of very fine plastic mesh and can be hemmed with a hot metal clad resistor or hot melt glue in very small spots. |
22nd Feb 2020, 11:48 am | #10 |
Nonode
Join Date: Jun 2007
Location: Coulsdon, London, UK.
Posts: 2,171
|
Re: Vintage radio loudspeaker dust bag
I tried to identify the type of fabric used for the dust bag in an old radio.
I think it was a Philips or an Ultra. The type of fabric does vary. Some are surprisingly brittle. If you use the search term 'japanese double gauze fabric black' on a well known internet auction site, you may find a black lightweight open weave cotton fabric that looks similar to the vintage cloth. I have not bought any fabric yet. I want to check at a fabric shop first to see what options are available. |
22nd Feb 2020, 12:02 pm | #11 |
Nonode
Join Date: Jun 2004
Location: Norwich, Norfolk, UK.
Posts: 2,543
|
Re: Vintage radio loudspeaker dust bag
On the two occasions I had to remake these bags I found the originals to just be simple square bags with a drawstring at one end. I used a cheap black bed sheet to make the replacements.
David
__________________
http://www.youtube.com/ My Nixie Clocks |
22nd Feb 2020, 12:03 pm | #12 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,970
|
Re: Vintage radio loudspeaker dust bag
An old polyester cotton bed sheet will probably be OK. Even if you have to buy one from Primark it will be cheaper than buying a metre of fabric from a haberdasher (if you can even find one). Many of the original bags were unbleached cotton so a sort of cream colour, while others were dyed black.
|
22nd Feb 2020, 12:22 pm | #13 |
Heptode
Join Date: May 2017
Location: Konongo, Ghana
Posts: 516
|
Re: Vintage radio loudspeaker dust bag
According to Philips the purpose of the bag is suppression (about 6dB) of the lower resonance frequency. Source: p. 157 "Van microfoon tot oor", G. Slot, second edition, 1960, Philips Technische Bibliotheek.
|
22nd Feb 2020, 1:25 pm | #14 |
Heptode
Join Date: Apr 2016
Location: Cheltenham, Gloucestershire, UK.
Posts: 875
|
Re: Vintage radio loudspeaker dust bag
I've made a few of these - usually for Phillips sets [V5A's etc.]. I've always used fine white muslin [dyed where appropriate]. As others have stated - this entails cutting-out a circular shape; hemming the perimeter; and threading a tie cord through the perimeters' hemmed section i.e. prior to 'shrouding' the speaker itself.
__________________
Red to red, black to black. Throw the switch and stand well back! |
24th Feb 2020, 8:55 am | #15 |
Hexode
Join Date: Sep 2005
Location: Potton, Bedfordshire, UK.
Posts: 293
|
Re: Vintage radio loudspeaker dust bag
Guys,
Thank you for all your suggestions. Paul mentioned using a sheet but I have found pillow cases are a lot cheaper than a whole bed sheet and would certainly provide enough material to make one - assuming that the material is suitable. Its not a Hi-Fi speaker by any means but a vintage Tannoy model as installed in buildings on military bases. Alf |
24th Feb 2020, 11:59 am | #16 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,970
|
Re: Vintage radio loudspeaker dust bag
Yes, a pillowcase would be fine if you are buying new. I only mentioned a bedsheet because lots of people have old worn ones sitting in a cupboard.
|
24th Feb 2020, 5:50 pm | #17 |
Heptode
Join Date: Sep 2014
Location: St Albans, Hertfordshire, UK.
Posts: 594
|
Re: Vintage radio loudspeaker dust bag
I used the wifes washing bra bag it was perfect size and has draw strings to close it as I said it was perfect well until the wife asked if I had seen and of course I said no lol
|
24th Feb 2020, 7:48 pm | #18 |
Octode
Join Date: Oct 2011
Location: Wrexham, North Wales, UK.
Posts: 1,457
|
Re: Vintage radio loudspeaker dust bag
If the OP has not yet found a workaround, I have one taken from an old 40's speaker if it's any use, it has not crumbled away as of yet.
__________________
Rick, the annoying object roaming the forum. |
25th Feb 2020, 2:03 pm | #19 |
Heptode
Join Date: Feb 2013
Location: Rainham, Kent, UK.
Posts: 525
|
Re: Vintage radio loudspeaker dust bag
Last year I Re-bagged a speaker on a 1946 Ekco. After a few fails, I purchased Muslin (Cheesecloth / Midex M34) from an auction site £5.50 a metre. I purchased it in black, other colour are available including white. It was indistinguishable from the original, I was really happy with it, it looked totally original. This speaker had an open Speech coil, so I felt happier with it having an extra layer of protection.
|