Simple speaker repair

We’ve all done it, been enjoying the tunes a touch to much and either cranked up the bass or the volume, then comes the dreaded crackly sound from the speaker (or worse yet silence but that’s an issue for another day!) you take a quick look at the speaker and see the foam surround is split 😩

Now you realize you can’t turn up the speakers in any meaningful way without them sounding brutal 😞.

So how do we fix this problem?

The solution is actually relatively easy and simple to do! (with a little care, a steady hand and some basic tools!) we recently had this exact problem on this set of speakers so we decided to do a simple walk through of how to fix this!

Where to start?

To Start with were going to need the sizes of the foam surrounds, to get that were going to need to remove the speaker from the housing.

Removal

To remove the speaker from the housing (usually fairly simple, some are pull off and others unscrew )


Obviously there’s 4 screws here to remove.

Carefully lift the cover (others maybe different )as you can see we have to disconnect the tweeter wires before we can fully remove the cover (these are push on connectors, so carefully pull them off)

Now we remove the speaker screws and carefully lift out the speaker

again these are push on connectors so we going to carefully pull them off, others types maybe soldered, so you’d have to either de-solder them or rest them on the housing while you do the repair.
Now we have the actual damaged speaker out of the housing we can get a look at it

Here we can see the split surround of the speaker now its out of the housing (we temporarily filled the split with silicone sealant to last until we could do the repair correctly)

as we can see from the back of the speaker this is an LG speaker, we can use the info here to try finding a match for our foam surrounds when getting the repair kit 😉

Get the surround sizes

First up is to work out what size the foam surrounds are:
⁃ grab the damaged speaker and measure the overall outer diameter (the red line measured at the center point ).
⁃ Then measure the first start of the shoulder (the outward bump) nearest the outer edge.(the blue line measured at the center point ).
⁃ Now measure the inner shoulder(the green line measured at the center point ).
⁃ Finally (if it’s mounted on the back like these speakers it’s harder to measure and you’ll probably have to judge it, if the inner edge is on the speaker front measure that too (the yellow  line measured at the center point ).

(all measurements are taken at the center line we separated the lines for clarity).

Order the parts

So now you’ve got 4 measurements you can use to make sure you get the right size foam surround, we used: https://lautsprecher-technik.com ( who incidentally have a how to video on their website shown here).

To get our new surround repair kit which included the surrounds x2, glue and glue remover, we searched for LG and the number on the speaker but couldn’t find a match to ours, so we searched through to find a kit that matched the measurements we had take from the surrounds, this speaker is a 5 1/4” (125mm aproximate) but if you’ve a brand name and model you’ll likely be able to search and find it faster😉
– (For the above speaker we ended up ordering the Bang & Olufsen beovox M100-2 midrange kit although this clearly isn’t a Bang & Olufsen speaker! because the dimensions of the surround specified on the https://lautsprecher-technik.com matched what we needed this time ).

(Repair foam surrounds and glue remover were ordered separately on this occasion, the remover is in a similar  bottle to the glue,that was due to an error on our part when ordering and didn’t select the glue remover to be in the kit 🤦‍♂️ ).

Now I have the foam repair kit what’s next?

So now you’ve got the repair kit the next thing to do is to check the surrounds you’ve bought are at least similar to the ones your replacing!, as a quick reference you can offer the new ones up against the old ones.

Here we just laid the new ones over the old ones just to double check they would at least be similar (they were a very close match!)

Surround removal

Now we’re going to remove the foam from the cone and frame (the white cone and metal frame)
For this step we’re going to be using the glue remover, we totally recommend doing this outside as the glue remove has some fairly strong smell and fumes !
⁃ Apply the glue remover round the foam surround edge on the frame

Then give it 15 minutes to soak in and do it’s thing

Using a razor blade carefully lift the surround from the frame ( note wearing gloves as the remover isn’t nice stuff for skin!)
When the outer edge is free from the frame apply the remover in the same fashion to the inner edge on the back of the cone, and let it soak in for another 15 minutes.

Carefully separate the foam surround from the cone, once it’s all free remove the old foam surround and clean the old glue from frame

And the cone

Until everything is clean ( note that we made a pen mark around the foam  support surround on the back of the cone to serve as a rough guide later)

Now we give it all a wipe and clean to make sure there’s no extra glue remover lying around that might interfere when we glue the new foam surrounds in place later.

Fitting new surrounds

To fit the new surrounds we basically have to just center them and glue them in place.
First we check the surround fits

(Not glued onto place but is a nice snug fit to the cone )
We now apply the glue to the back of the cone

Using a cotton swap we smear a thin layer of glue around the edge of the cone ( similar in width to where the old glue / foam surround sat, the yellow mark is roughly where ours was) and place and center the new surround  (we used the crease of the new foam surrounds inner shoulder as a guide to centering the cone in the foam surround)

As we marked the original with a pen we can see when the new surround is fairly even around the old fitting ( the surrounds vary in size and have a fairly big tolerance so it’s unlikely it’ll match the old one perfectly but even is good enough!)

Now we have the surround glued to the cone and evenly mounted all round, we have to let the glue set for 15mins or so.

Now we run an even bead of glue round the outside metal frame and again smear it evenly with a cotton swab and press the outer edge evenly into place, ensuring the cone is centered ( has an even gap all round the surround and frame)

We let that set for 15 mins before reconnecting and refitting the speaker to the housing ( reversal of removal procedure we did at the start).

reconnect the speaker and refit to housing, screwing back into place.


Reconnect tweeter and refit to housing.

All back together now we have to reconnect and test it all works.

  • once this was all done we found the speaker worked correctly again with no nasty noises👍

Contact us

That’s it for this how to but if you’ve any questions or suggestions, feel free to drop us an email and we will see if we can help.

Not affiliated

We are not affiliated with https://lautsprecher-technik.com/
We have received no payment of any kind for this article. We found the product shown here to work well and have clear instructions and we were able to support a local company here in Germany During the Covid-19  lockdown and carry out  this “how to” safely at home 👍.

Disclaimer!

This “how to” is intended as information only!, we accept no responsibility for anyone attempting this regardless of skill or qualification and any damage from anyone or thing caused intentionally or unintentionally in any manner whatsoever!, if you are not sure please consult a audio professional!

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