Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Meridian Tweeter repair

I noticed recently that one of my 25 TAFC/GW-BS1 H1054 - 6 Ohm (Black Dome) tweeters had reduced output and had gone "soft ", switching tweeters confirmed that it was only this tweeter that was affected. I brought out my reserve H539 that was OK 3 years ago only to find that it too has reduced output. Given that the only new replacement from Meridian, the H1612 is not a match above 10Khz I thought that I would look into the possibility of repairing the tweeter myself.

https://www.flickr.com/photos/190748481@N07/53484333853/in/album-72177720314286497/

After opening the H1054 it was clear that the ferrofluid had become stickier and there had been wicking onto the absorbent gasket so I think that replacing the ferrofluid will be beneficial.

I contacted Meridian and Seas about the properties of the ferrofluid and Meridian replied that they do not have that information now, Seas have yet to respond. Has anyone else any information about the ferrofluid used or what anyone may have used in a successful repair?

There are a couple of generic types for tweeters available which I will try if I cannot get anymore information but I thought I would ask for any advice on here first.

If the ferrofluid is not an exact match I still don't have anything to lose as my only alternative will sound different anyway.

I will keep you updated over my progress over the coming weeks and will update the photos on flickr with a how to of sorts.

Rgds
Stuart

This will be interesting as Meridian replacement tweeters have recently gotten very expensive here in the US, so much so that it may not be worth trying to refresh a set of speakers as the tweeters cost more than the speakers are currently selling for second hand. On the other hand maybe it may drive up the used prices if replacement tweeters are installed. Who wants to take on a $1000.00 experiment 😃

Hi

I replaced the fluid in the tweeters on my old M30s. I just bought the fluid on eBay and it was a relatively easy if fiddly job.

The performance was vastly improved, amazing how one gets used to slowly degrading performance.

Good luck.

This is interesting. How did you remove the screen grille without damaging it?

The screen is held on by a light adhesive. a gentle levering through one of the holes at the edge with a jewelers tool kit loosened it just enough to prise around the edge.
Rgds
Stuart

Ferrotec suggested using APG L11 as a universal replacement and said that it could be bought from partsexpress in the US.
They quoted $127 to ship under 1ml to the UK. I have emailed ferrotec.de to find a european supplier.

Rgds
Stuart

Had the following reply from Seas today ...So I have managed to get someone to send me some APG L11 which should arrive next week and hopefully will be enough to do both the H1054 and the spare H539.

I will keep you posted and take lots of pics.

Rgds
Stuart

I received my Ferrofluid today from an eBay Shop in the UK.

I've also taken pictures to document the process for the 2 tweeters and have put them in the Gallery.

The entire process for the 2 tweeters took just over 2 hours including some time documenting the process with photos and a video, and the result is that the H1054 tweeter is now fully repaired and functioning exactly as it should.

The H539 tweeter has improved slightly but is still muted in the higher frequencies and as such I would not use it. I am assuming that as well as the ferrofluid drying out on this one it has also suffered from degradation of the suspension perhaps, or alternatively I just did not do the replacement correctly?

I did the H1054 first and have to say that I noticed that the H539 voice coil did not seem nearly as robust as the black domed one, maybe if I had not cleaned the voice coil and only cleaned out the magnet gap I may have got a better result.

I will write up my full method and post here tomorrow.

Rgds
Stuart

I’d love to be brave enough to try this on some of my older speakers. At present I think they’re ok but that could just be my presbycusis, either way I’ll live with them a bit longer for now. Well done though!

Meridian tweeter ferrofluid replacement ,equipment Required.

1 pack APG L11 900microlitres
available here for the UK
https://www.eBay.co.uk/str/billynomates67m?_trksid=p4429486.m3561.l2563
and here for the US
https://www.parts-express.com/Ferro...e-for-1-Diameter-V.C.-340-540?quantity=1

several strips of blotting paper or filter paper
70% isopropyl alcohol
Small jewelers screwdrivers
cotton buds
wooden kebab sticks cut to 3 inch lengths approx or matchsticks of the right dimensions.
torx screwdriver
small syringe
superglue

Method

Be aware that any metallic objects such as screwdrivers and screws will be attracted towards the magnet and as such care needs to be taken to avoid damage to the dome. Ensure the area is clean. Ferrofluid is an irritant, if you get any on your hands wash it off immediately.

Insert a small screwdriver through one of the holes near to the edge of the grill and lever against the surface of the tweeter plastic just enough to lift up the edge of the grill in order that you can insert a slightly larger screwdriver under the edge, now remove the first screwdriver and work around the edge of the grill easing it off as you go.

Remove the 4 torx screws holding the tweeter together and set them off well to the side away from the magnet. Note the orientation of the terminals relative to the label and if you can mark both sides to ensue it goes back together the same way.
Separate the plastic assembly from the magnet, if there is resistance use one of the small screwdrivers at the interface between the two halves to loosen them. Place the voice coil assembly dome side down on a flat surface.

I opted to clean the old ferrofluid from the voice-coil with a cotton bud soaked in IPA however these parts are extremely delicate and easy to deform so it may be that this step was unnecessary. If you are at all unsure then I would omit this step. I did the H1054 tweeter first and found that the H539 voice-coil seemed way more delicate.

Insert a strip of blotting paper into the magnet gap and run it around to soak up as much old ferrofluid as possible, repeat this step five or six times until the strips are almost clean when they come out.

Place a very small amount of IPA into the magnet gap being careful not to spill or overfill and leave this for a minute.

Now repeat the steps with the blotting paper until they come out clean and dry. Set aside of 5 minutes to dry out.

Fill the gap with ferrofluid to about 75% or until you can just see it, the ferrofluid should run into the gap without having to squeeze it much, if you overfill the gap use blotting paper in the gap to remove some. There was enough ferrofluid to do around 3 tweeters.

Screw two of the wooden dowels or matchsticks into two of the screw holes in the magnet assembly, they should be a reasonably tight fit as if they are too loose they may result in misalignment of the voice-coil with the gap resulting in potential damage to the voice coil.

Align the voice-coil assembly with the wooden guides ensuring the orientation is the same as when it was taken apart and ease the two halves of the tweeter together. On my two tweeters there was a tab on the magnet gasket at the same side as the terminals.

Fit the torx screws.

Use superglue to refit the grill.

Test the tweeter. I used a mono signal to my speakers and used the balance on the remote to compare the refurbished tweeter to the undamaged one on the other speaker and could tell no difference in performance between the H1054 that was repaired and the original in the other speaker so absolutely a success there.
I adjusted the tweeter output on the donor speaker and fitted the H539 and performed the same tests and although the tweeter had improved from before it was still slightly muted at high frequencies so I would not use this tweeter.

I would not recommend routine replacement of the ferrofluid on a tweeter that is still performing well as there are risks in this process, the old adage if it ain't broke don't fix it would be my advice.

It took me 80 minutes to do 2 tweeters and some of that time I was filming and taking pictures to document the process.

Rgds
Stuart

A short video of process on YouTube.

Rgds
Stuart