Having recently bought myself a pair of Gale GS401As in need of refurbishment, the time has come to make a start on doing them up. Having previously made some notes on re-foaming my Gale GS401Cs and Gales GS301s, I thought I’d do the same for these and try and get a more-or-less end-to-end document for anyone following in my footsteps.
I don’t profess to be an expert and frequently have to rely on help and advice from others, and where that is the case I will try acknowledge it and credit them.
What I do have now is the experience I have gained, and that’s what I am trying pass on here, in the hope that I can help others avoid the pitfalls that can potentially waste time and undo good work.
I will be publishing this article piece-meal, updating the various sections as they are completed, so if you come across a subtitle with no words or pictures, odds on it is still work in progress.
Finally, please feel free to ask questions, make suggestions or offer constructive criticism in the comments.
Dismantling , Refurbishing and Reassembling Gale GS401A Loudspeakers
Part 1 – Remove chrome caps and speaker cloth.
Tools: a mallet, a small block of 2×1 timber, a pair pliers, a small/medium screwdriver, preferably old and a little rounded off.
I also found it useful to have a notebook, pencil and digital camera on hand to record what went where and how before I removed it. In order to ensure that the components go back into the same cabs and in the same position, I used coloured sticky notes to identify parts to speaker cabs.
1a. Remove chrome caps
Each of my end caps were secured by two large blobs of glue that had long since dried out, so all that was required were a series of firm taps around the rim using a block of 2×1 and a mallet. Once that got them moving it was no trouble to pull them away.
The obvious things to be careful of are ensuring that you perform the task in an environment and in such a way that will neither scratch your chrome nor damage your drivers as you manipulate the speakers.
1b. Remove the speaker cloth
The speaker cloths are secured by numerous staples and also have a plastic ‘vanity strip’ located either side of the crossover panel on the rear of the speaker. You can see the edge of the cloth secured by staples plus a small section of the vanity strip in the picture above.
To remove these start by prising away the vanity strips and simply pulling them up and away from the speaker.
That done, all of the staples should now be exposed, so work around one side at a time, methodically levering up one side of the staple with the screwdriver, taking care not to stab yourself or, worse, your speakers! Once you have done that use the pliers to remove the staples.
Once that is complete the speaker cloth will come away. I took the opportunity to measure mine at this point (the dimensions were 90 x 56 cm) as, despite being in very good condition overall, there were a couple of tiny holes that warrant replacing them.
Finally for this section, there should be a small ‘platform’ of hardboard and foam (see above) stapled to either end of the front face of the speaker. I found the best way to remove this was to simply grasp them with my fingertips and pull up and away from the speaker. This expose a number of staples on either the cabs or the platform that you can then pull out with the pliers.
If your speakers are in need of attention where the midrange and bass drivers are concerned, this is the sort of thing that will greet you when you have fully exposed them.
Interestingly in my case, one side was worse than the other and I found myself wondering if the side with the more disintegrated foam surrounds had perhaps been located nearer to a heat source, or been exposed to more direct sunlight?
I had a bit of a light bulb moment while re-reading the caption above; I suspect that the foam surround above may have been purposely inverted rather than have collapsed as stated. I vaguely recall reading somewhere instructions that alluded to (they certainly weren’t clear or illustrated) the possibility of fixing them either way up.
As the picture above shows, the grille that protects the dust cap had fallen off at some point when the glue that secured it dried up and failed, and as a result the transparent dome had been crushed.
The repair was fairly straightforward:
Various options were put forward for pulling the dome back into shape:
- ‘kissing’ the tweeter – i.e. using gentle suction
- using a vacuum cleaner to do the same as (1)
- using adhesive tape
I replaced the original gasket with PVA glue.
Finally I replaced the grille using double-sided tape. I shied away from using really powerful adhesives in case I need to remove it at some point further down the line.
Part 2 – Remove the speaker drivers
Tools: a cross-headed screwdriver, a flat-headed screwdriver and a soldering iron.
Carefully remove all of the screws from the drivers that will be coming out of the cabs (I say carefully on account of having once stabbed a hole through a newly refurbished foam surround!), then use the flat-headed screwdriver to carefully lever up the drive units paying special attention to the foam gaskets underneath.
Once the wires are accessible, de-solder all of the joints, making a note and/or taking pictures of which wire goes where. Note the red dots on the chassis – remember which wires attach to this side for reattachment. The tweeters are straightforward, with the red and black wires from the crossover effectively joining their corresponding counterparts on the driver.
Mine looked like this:
- ‘Top’ bass driver – purple wire to red dot
- ‘Bottom’ bass driver – red wire to red dot
- Midrange – yellow wire to red dot
- Tweeter – red and black wires go to corresponding terminals
For the purposes of consistency I have defined ‘bottom’ as being the lower portion of the speaker when the it is stood on end with the crossover nearest the floor. However, as the speaker is meant to be mounted horizontally this definition has no real meaning outside of this context.
Part 3 – Remove the insulation and crossovers
As the caption above hints at, the 30 year-old fibreglass insulation material layered inside the speakers is quite literally incredibly irritating to deal with if not handled properly, and as such I was advised by Dave Smith of Vintage Gale to undertake this portion of the work outside. Having fallen foul of this stuff once before when laying floorboards in my loft, I also went further to ensure that as much bare skin as possible was covered (rubber gloves, long sleeves, face mask), as the irritation can go on for days.
The picture above might give the impression that the insulation is stuffed in. However, once you remove the first piece it becomes apparent that it is layered in a reasonably ordered fashion.
There are two pieces doubled over with the creases facing in to centre under each of the bass drivers.
I bagged all of the pieces for each speaker into its own bag. I know it’s a desperately dull picture, but this is what you are looking at for one speaker, so be prepared with a couple of large bin liners and some means of sealing them shut, such as rubber bands or ties.
I temporarily taped the wires into their respective positions for this shot to provide me with a clear reference of what goes where when it comes to reassembly:
To remove the crossover unit I flipped the speaker onto its side and faced it way from me. I then unscrewed to bottom row of three screws, followed by the two outside screws on the top row. With my free hand I then supported the crossover while I unscrewed the last screw. Oddly enough there was one screw on each speaker – the last one – that wouldn’t come out of the cabinet.
These units look a lot better than the ones that came out of my GS401Cs, but will still be inspected for failed components and if necessary repaired before they are replaced. However, it’s at this point that my knowledge dries up and I send the crossovers off to someone who knows what he is doing – i.e. David Smith at Vintage Gale.
Part 4 – Re-foam the bass and midrange drivers
4a. Remove the foam surrounds from the bass and midrange drivers
Tools: A scalpel and an old chisel
- Using the scalpel, carefully describe (cut) a circle in the foam using the edge of the cone as a guide, i.e. separate the driver from the foam surround.
- Next, use your fingers to remove as much of the foam surround as you can. You will be left with a small amount stuck to the speaker cone and considerably more stuck to the metal chassis.
- Using the scalpel, carefully work around the cone separating the foam and old glue away from the paper of the cone.
- Finally, using the chisel, work around the chassis and remove the foam and glue from the metal.
Note: at this point you may want to consider painting the bare metal of the chassis black. I elected not to do this and ended up doing it after the new foam surrounds had been glued in place when it became apparent that the silvery metal might reflect light through the speaker cloth.
4b Re-foam the drivers
Tools: Replacement foam surrounds, PVA glue, applicator for glue, voice coil shims (optional), scalpel (optional)
The next part of the process happens in two parts on account of the need to allow the PVA glue to dry properly. In the first part the new foam surround is glued onto the cone of the bass or midrange unit. In the second the foam surround is fixed to the metal chassis of the driver. The process is essentially the same with a small deviation necessary for the midrange which I will detail later.
- Apply a thin line of glue 2mm or so into the circumference of the cone in question
- Use a child’s paintbrush to spread it out to a width of 5-7mm
- Place the foam surround centrally on the cone (do not worry about how it aligns with the chassis too much at this point) and go around the circumference of the cone carefully applying firm pressure to the foam surround
- Use kitchen roll or similar to clean up the excess glue
- Midrange: at this point you may need to place a small cup over the foam surround to weight it down
- Allow to dry for several hours, or better still, overnight
For the next part of the process opinion is divided as to whether it is necessary to use paper shims to ensure that the voice coil does not rub as the speaker cone moves in and out. This is the fourth pair of speakers I have re-foamed and I have managed to avoid shims so far. I will therefore detail the process without reference to ‘shimming’, and briefly summarise it here by saying that it involves cutting the domed dust cap off of the cone with a scalpel and inserting small pieces of paper to act as spacers while the foam surround is fixed to the chassis. Once drying is complete the shims are removed and the dust cap glued back in place.
- Lift the foam surround and place a similar line of PVA glue on the chassis of the driver
- Using a spreader of some description, go around again, ensuring that the glue is evenly spread and will secure the foam surround all the way out to the edge
- Once again, go around apply firm pressure to ensure an even bond
- Carefully, using four fingers placed equidistant around the cone near the dust cap, ‘bounce’ the cone up and down through 3-5mm to check for rubbing, which if present you will feel and/or hear
- If you detect any rubbing you will need to find a point on the outer edge of the new surround where, when it is pulled outwards in this direction (it is only a tiny adjustment) the rubbing is alleviated; affix clothes pegs to this area and try again, adjusting as necessary
- Once you are happy that there is no rubbing, allow to dry for several hours or overnight
Note: on this occasion I detected a couple of ‘rubs’ on the bass drivers both before and after I had glued the surround to the cone, and was prepared to make the adjustments detailed above when glueing the surround to the chassis. However, once the glue was applied I retested before making compensating adjustments and found there was no longer any need to do so.
Part 5 – Replace the crossovers and insulation
Note: while putting my GS401C back together today I discovered a handy way to replace the components that is much less stressful than the description below. Obviously it is basically the same process, but in a slightly different order.
- Replace crossover according to instructions below
- Put wadding in ‘top’ section first
- Put crossover in next
- Position wires according to description above
- Solder in top bass, midrange and tweeter
- Position wires if necessary, then replace wadding over crossover.
- Wire in bottom bass driver
I found the easiest way to put the crossovers back in was to first push the screws part way in from the rear of the cabinet, and then to hang the foam ‘gaskets’ in position on the inside. After that it is a case of carefully insering the crossover into the cab and getting the first screw lined up, after which the rest follow on relatively easily.
The fibreglass insulation goes back in a relatively orderly fashion, building layers up from the bottom of the cabinet and repositioning wires as you go.
Part 6 – Replace the speaker drivers
All pretty straightforward really, although to avoid facepalm moments make sure that you:
- put the gaskets back in place before you solder the drivers back in place
- take care with the screwdriver – those new foam surrounds hole easily if you slip as I did on my GS401C project
Part 7 – Replace the speaker cloth and chrome caps
7a. Replace the cloth
I suspect that most speakers undergoing the entire process detailed above will need to have the fabric covering them replaced. You are essentially looking for two pieces of ‘acoustically transparent’ speaker cloth measuring 90 x 56 cm.
Against my better judgement I bought a cheap staple gun from eBay and that was a big mistake as about 1-in-3 staples had to be pulled out and restapled, meaning that I didn’t put as many in as I ideally should have on account of the frustrating nature of the exercise.
Also, I started on the back of the speaker with the edge of the cloth aligned to the groove for the plastic trim on one side, and then similarly secured it on the other side, ‘filling in’ the centre afterwards. I suspect that if I do it again (and I might well when I buy a decent staple gun) I will start with the speaker on its back with the cloth evenly distributed across the front and draped down the sides. The first staples will go into the centre of the foam-covered hardboard platforms and the remainder distributed out to the sides, tensioning as I go.
7b. Replace the chrome caps
The chrome presents something of a challenge if it is seriously corroded or scratched, since replacement is the only option and that runs to somewhere in the region of £200 for four trays at the time of writing.
I was fortunate in that my chrome caps were only slightly pitted and any scratches aren’t obvious until you get in really close. As such I was able to polish them up with some Autosol liquid chrome cleaner, which is both cheap and easy to apply.
Of course, chrome represents another challenge… to the photographer! These aren’t the best pictures but hopefully they convey the sort of thing that can be done with a little polish. There probably isn’t much point putting lots of effort into the polishing before you replace the caps, as they will inevitably end up with palm prints on them, unless of course you are prepared to buff them up afterwards.
I was reliably informed that the chrome caps can simply be pushed home. Pondering this it occurred to me that what I initially took for adhesive on the end of the cabinets might actually have been used to secure some foam to prevent vibration of the caps under more ‘extreme’ use cases!
However, when it came time for me to replace mine, two took a nice firm push to get them all the way home home, while the other two went on rather too sloppily for me to have confidence in them when subsequently handling the speakers. As a result there may be a little work to do there in order to better secure them.