Ekco A274. Speaker help.

[robreddog]

hi, been listening to the ecko a274 for a few weeks now but one of the speakers started to sound off (flabby, i would describe it).
removed it from the cabinet and repaired the many small cracks 90 deg away from cone edge and repaired as described in the forum with fag paper and pva.
sounds better but still not like it was,there are screws that i could play with but could anyone help with info on what else i could do to improve things.
Rob.

[paulsherwin]

You could just replace the speaker with one from a scrap set, as I don't think there's anything special about it. These radios have two speakers to spread the soundstage, but they're not really matched in any meaningful way.

[robreddog]

hi,
done some research and could be i have a rubbing voice call ?.

[G6Tanuki]

It could be the voice-coil rubbing on the magnet, yes.

In the past I've had speakers that sounded 'scratchy' - specially at low volume - which was caused by rust on the central part of the magnet/coil assembly. If the radio's been stored in a damp/unheated environment this is a definite possibility. The rust particles - even if detached from the magnet - are hard to remove without dismantling - the rust is magnetic.

[mark pirate]

As a last resort, you could try loosening the two screws on the magnet (not the nut in the centre) and tapping it in various positions to centre the voice coil.
I have repaired a couple of Elac speakers this way.

If there is rust in the voice coil gap, obviously this method won't work.


Mark

[jonnybear]

An old dodge was to place a cotton wool ball between the chassis and the cone
working your way around the speaker with the ball, if you find a position that the speaker sounds good, the is cone probably warped,either leave it there until you come across another speaker or give Marks idea ago to try and centre it.
John

[McMurdo]

I would play some tones through it with a signal generator if you have one and see if you can narrow down the distortion. Resting a finger lightly in various places sometimes helps to isolate the problem. It would be a shame to write it off or do something drastic if it turns out to be something simple.

[Glowing Bits!]

I would agree with Kevin on this one, a sig-gen set to low frequency does come in handy when diagnosing faults with speakers, the prod test does reveal things eventually.
I have come across a speaker in a worse state than the OP's, it had a reconstruction performed with the cone, loo paper & PVA came in handy.
As for how to align things, I gave up with a DAC90 speaker, nothing worked, a replacement sorted that out.
As a heads up, could the OP measure the said speaker? I may have something similar in an old Ekco set.

[robreddog]

Hi, thanks for the replies, I would like to try to repair or rebuild the speaker, I will measure and inject hz from my phone app, and report, do you think I could find a diagram of the coil anywhere before I open it up??.

[crackle]

Check the inner suspension near the voice coil has not come loose from the frame.
If it has then it can be glued back in place with PVA. But if there is rust present do not try to remove it as it will be pulled into the voice coil gap, you could treat the rust with a proprietary rust converter, prior to gluing.
You may need to carefully cut the speech coil dust cap away so you can get 3 shims in the gap to help centre the voice coil. You can glue the dust cap back later with PVA.
Mike

[Edward Huggins]

Let us know how you get on. But don't compromise the sound on this fine radio if it still ends up sounding tizzy. It's a 6.5" full range driver of 3 ohms. It does not need to be an Elac as there were were many makers of ths popular size. You can readily source a replacement Online or maybe from a Member here.

[robreddog]

hi, not very well, loosened the two screws and now little movement on the voice coil/cone, so looks like major surgery, i will check around see if i can find spares suppliers, would of thought 6" speakers stuff would not be to hard to find ??.
All the messing around has made a load more cracks in the cone as well.
all tips gratefully received.
the overall speaker dia is 6.75"
Rob.

[crackle]

I hate to say this but the speaker is probably beyond help now that the screws have been released. It would appear that the magnet housing and centre magnet pole have been pulled over to the edge and stuck fast to the other pole trapping the voice coil in the process.
I dont think even dismantling will fix this.

One last thing you could try is carefully cut away the dust cap with a scalpel and insert two hard plastic shims about 30mm long by about 8mm wide (I use the type of hard clear plastic that comes with those horrible bubble packed items that are impossible to open) in the gap opposite to the point where the voice coil is trapped, tighten the screws to just finger tight then tap the magnet housing gently with a light hammer so that it is jolted away from the edge. Insert a third shim into the new gap, gently tap all around the magnet to try and get all 3 shims as loose as possible, do the screws up and try and pull the shims out whilst holding the cone down.
Hopefully you will be at the stage now before you loosened the screws.
Check the inner corrugated suspension has not come away from the speaker body.
Mike

[robreddog]

removed the dust cap,but that revealed a different internal to what i have seen on youtube,can anyone recognise or describe it, the coil is "fully in" i will try to find another coil but ultimately will have a go at repair when i can find some information.
Rob.

[robreddog]

here are a couple of pics

[mark pirate]

I am surprised that the speaker uses a spider, this is only normally seen on older speakers.
It looks to be cracked on all three supports, I think I would just look out for a suitable replacement, as that is not worth the effort of going any further.


Mark

[clockman]

I find in most of the sets I get the speaker is a total write off due to the fragile cone and rust I would like to find a supplier of small replacement speakers at a reasonable price as for me this is a big problem.

[Andy Westcott]

Watch out for efficiency; These old speakers were very efficient and you may find a modern replacement will have a rather lower sound output.

[David G4EBT]

Originally Posted by robreddog

here are a couple of pics

I guess it depends on how adept and patient you are, but if you were so inclined, you could perhaps remove the spider and use it as a pattern to make a replacement from 1mm thick phenolic paper sheet ('Tufnol') using a fretsaw. If it doesn't work, then you've left no stone unturned and you've been curious enough to remove the cover to reveal the problem.

You can get a 200mm square sheet in brown or black for £3.10 post free from here:

https://www.ebay.co.uk/itm/1-mm-Phen...-/360493305365

Many will say 'why bother going to that trouble when you can just replace it?'

All I can say in response, is that completing skilful little tasks is what gets me out of bed each morning and sends me to sleep happy at night.

I do lots of things where - from an accountant's point of view - there isn't any cost/benefit argument and I'd be laughed off the face of the planet by an accountant. But how do we value the 'benefit' of the satisfaction, joy and self-esteem and wellbeing derived from doing common things uncommonly well? I put a high price on that. There is no economic argument to justify the time, effort and expense in any of my hobby activities, but do you know what? I couldn't be more contented, happy and chipper. Try and price that up!

Good luck in sorting it whatever you do Rob.