So, I messed up a little...

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Thats the crossovers not protecting the speakers. or the amp loosing control. I highly dbout that is rumble you would see that quite early on with the volume.

Glad you're getting it sorted anyhow im sure you'll be back up and running in no time.
Cone flap is not volume dependent, it's an issue with turntables and feedback, some speakers are more prone to it than others.
Warped records don't help either.....
 

Gray

Well-known member
Cone flap is not volume dependent, it's an issue with turntables and feedback, some speakers are more prone to it than others.
Warped records don't help either.....
Yes, with no subsonic filtering in the amp, warps can cause cone flap - without any need for feedback - subject to the cartridge compliance (depending on whether the cantilever rides or absorbs the warp).

Cone flap is a result of the amp boosting the subsonic frequencies that we can't hear -and as such, it is volume dependent - zero volume and cone flap is zero.

Cone flap caused by feedback will probably cease below a certain volume threshold - but the feedback loop (whether structural or airborne) needs to be broken - so that there is no feedback at any volume level.

Here's a question:
On the older amps with switchable subsonic filters....why was the filter switchable and not permanently on like in other amps?
 
Yes, with no subsonic filtering in the amp, warps can cause cone flap - without any need for feedback - subject to the cartridge compliance (depending on whether the cantilever rides or absorbs the warp).

Cone flap is a result of the amp boosting the subsonic frequencies that we can't hear -and as such, it is volume dependent - zero volume and cone flap is zero.

Cone flap caused by feedback will probably cease below a certain volume threshold - but the feedback loop (whether structural or airborne) needs to be broken - so that there is no feedback at any volume level.

Here's a question:
On the older amps with switchable subsonic filters....why was the filter switchable and not permanently on like in other amps?
To be honest I don't know any amplifiers that had a permanent subsonic filter or indeed any that had switchable ones. The only filters I have seen have been on phono preamps and most of those don't have one.
 

Gray

Well-known member
To be honest I don't know any amplifiers that had a permanent subsonic filter or indeed any that had switchable ones. The only filters I have seen have been on phono preamps and most of those don't have one.
I don't know how to post online images onto here but the Yamaha CA-2010 is an example of an integrated amp with a subsonic filter switch.

People can check out the frequency response quoted for their amps to get an idea whether they effectively have built-in subsonic filtering.
My own (Cyrus) amp for example, amplifies 'from DC up', so most definitely does not have any subsonic filtering.
 

Din5

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You purchased these used, correct?
I'm guessing Focal will direct you to your local repair facility somewhere in the UK.
If used, I doubt that it will be covered under warranty.
Shipping (or 'carry in' if you are close enough), diagnosis and final repair is most likely going to be eye wateringly expensive. Focal's replacement drivers are notoriously pricey, even for their budget range.
It's probably going to be cheaper to buy another secondhand pair :cry:

You say you have a phono stage? You could research using a sub sonic filter between it and the amp input for future protection (unless it already has one or there may be a switchable/adjustable one in the
Perhaps the OP could find a replacement driver on ebay, maybe he could remove the driver in question to see the model number and check availability online. Or, perhaps the driver could be rebuilt ?
 

CGMe

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Ok, I manged to get the cover ring for the damaged driver off. It's glued on (wel, actually was) with a flexible glue, so getting it off wasn't that hard. The driver itself was fixed with 6 torx screws, which came undone very, very easily. Like the weren't really tightened in the first place, or they had been replaced before. Never gave it some thought before, but the lower bass driver actually has a slight smidge below the ring, as if someone spilled some glue and tried to wipe it. Another thing I noticed was that the insulation wasn't attached or glued to the wood. It's just in there, loose.

20240319_103538.jpg 20240319_103520.jpg20240319_104208.jpg 20240319_104522.jpg
 

CGMe

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Some videos of the damaged driver. I'm not a speaker export, so I don't know if I'm seeing it right, but to me it appears that I'm seeing some torn fibers in the cage. Oh, and that scraping noise... ouch. Another thing I noticed is in the second video. THere's some kind of foam ring on the back of the driver. Probably to close off any tiny gaps between the wood and the driver when tightened, but it's way off-center.


 
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CGMe

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Perhaps the OP could find a replacement driver on ebay, maybe he could remove the driver in question to see the model number and check availability online. Or, perhaps the driver could be rebuilt ?

I checked the back of the driver, but there's an incredible amount of lack of information on it. Just a little sticker with two numbers. Tried Googling either number in combination with "Focal" and nothing comes up. Guess I'll have to wait for the hifi shop to respond to my mail.

20240319_105924.jpg
 
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Some videos of the damaged driver. I'm not a speaker export, so I don't know if I'm seeing it right, but to me it appears that I'm seeing some torn fibers in the cage. Oh, and that scraping noise... ouch. Another thing I noticed is in the second video. THere's some kind of foam ring on the back of the driver. Probably to close off any tiny gaps between the wood and the driver when tightened, but it's way off-center.


Nasty! That’s definitely history, that driver. And badly assembled too.

I hate the trend for hiding fastenings to look cool. I’m reassured by checking the tightness every year or so, especially with sealed boxes. Less vital with ports, but without the foam yours might have conceivably buzzed at high levels.
 

Din5

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Can you try to connect a multimeter across the terminals to check if electricity can pass round the coil ? or , you could try connecting a battery, if you hear a click then at least the coil is still intact..
 
Here's a question:
On the older amps with switchable subsonic filters....why was the filter switchable and not permanently on like in other amps?
I recall that with full-range (or at least largish) speakers most subsonic filters did make the LF sound a tad weak too, probably as not ideally designed. But they would help reduce cone wobble on warps or badly mismatched arm and cartridge combinations. I believe British amps like Quad tended to roll of at LF anyway, whether to prevent subsonics or not isn’t clear. Amps like the big Sansui above would go very deep though. I had the monster AU-919 for a while, so I remember it well.

I think we got used to this disappearing once CD arrived, but now records, er, vinyl, is popular again…
 
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Din5

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I checked the back of the driver, but there's an incredible amount of lack of information on it. Just a little sticker with two numbers. Tried Googling either number in combination with "Focal" and nothing comes up. Guess I'll have to wait for the hifi shop to respond to my mail.

View attachment 6359
If things get difficult, i found this on naimaudio community web site..1710846665850.png
 
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Din5

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It actually does.
Ok, so the coil is maybe ok.
Can you try connecting the driver directly to the speaker outlet terminal of an amplifier (volume at very low). If you can hear sound correctly from the driver, then I would assume the problem is with the crossover unit in your speaker cabinet.
 

Gray

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Ok, so the coil is maybe ok.
Can you try connecting the driver directly to the speaker outlet terminal of an amplifier (volume at very low). If you can hear sound correctly from the driver, then I would assume the problem is with the crossover unit in your speaker cabinet.
His driver has always 'worked' but, he first reported a scraping sound - then subsequently, physically confirmed the scraping.
The (electrically intact) coil is fouling the magnet.
In its current state, the driver has no future....unless he needs a doorstop or paperweight ☹️
 
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gasolin

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No, a subsonic filter blocks the lowest frequencies.
So it's effectively a high pass filter - because it allows all frequencies above subsonic, to freely pass.
Thats what a subsonic filter is,does

 
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Thats what a subsonic filter is,does

Seems to be some confusion as this refers to subwoofers when the subsonic filter is one fitted to a phono stage, not quite the same thing in reality.
 

gasolin

Well-known member
low filter does the same but works on all inputs

Can help speakers that isn't that powerfull when playing loud to prevent the woofer from unwanted movemnents (or when using a turntable)

Something like 30hz -12db is a little more effective than 20hz -12db or mabye 15hz -6d

Mabye soft clipping or a limiter would have saved the woofer ?

Music don't have the same information in both channels (the midrange,midbass goes down to 270hz) so one might have been much louder for a split second, boom and it's damaged
 
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