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Old 11th Jul 2021, 12:40 pm   #1
Malcolm T
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Default Goodmans Magnum K2s M range

Can anyone tell me please how to remove the cones from this Goodmans cabinet,
in particular the main cone .
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Old 13th Jul 2021, 2:27 pm   #2
martiR2R
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Default Re: Goodmans Magnum K2s M range

I have Magnum K's - don't know if they are built the same as the K2, but the "grille" is bolted on from the inside so the rear panel has to be removed to gain access.

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Old 19th Jul 2021, 1:44 pm   #3
Malcolm T
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Default Re: Goodmans Magnum K2s M range

The back appears to be glued in place , there are no screw heads just a smooth surface , its exactly the same for the front panel where the speakers are fixed . I can only assume the cones and all are installed into a glued enclosure.
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Old 19th Jul 2021, 2:57 pm   #4
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Default Re: Goodmans Magnum K2s M range

Most online images appear to show foam (or velcro?) strips at the corners and no obvious screw heads or screw recesses, however this found image shows the foam or velcro strips missing and four plastic recesses / holes. Might there be screw heads lurking inside the recesses, if your speaker has these?
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Old 26th Jul 2021, 9:58 pm   #5
Malcolm T
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Default Re: Goodmans Magnum K2s M range

Its a mystery for sure , as there are no plastic inserts or anything, just six strips of wood with velcro stapled to them to hold the front cloth cover. Looks like more investigation reqd.
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Old 28th Jul 2021, 2:02 pm   #6
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Default Re: Goodmans Magnum K2s M range

I understand your problem. I had a pair of Wharfdale Super Lintons.
It was impossible to remove the back or front of the cabinet both were glued on. Maybe a cost saving measure?

The cabinets on mine were in very bad condition so I cut the backs out with a jigsaw! Probably not what you wanted to hear. But I think if you do it carefully you can cut out the back and replace with a new one cut to fit, mind you don't damage the crossover.

Trevor
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Old 28th Jul 2021, 2:21 pm   #7
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Default Re: Goodmans Magnum K2s M range

I needed to service a pair of Linn Kans that had broken terminals. The box is glued together and the drive units are similarly glued in.
I trepanned the back off the cabinets using a slitting saw in a milling machine but this could be done with a long hacksaw blade in a combination of hacksaw and pad saw.
Just be careful to only just cut through the wood as there are wires in the cabinet that it would be easy to cut and the cones & magnets are all too easy to cach.
I put them back to gether with No-More-Nails and screws.
Linn Kan cabinets are FULL.
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Old 1st Aug 2021, 2:24 am   #8
JimFromSurrey
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Default Re: Goodmans Magnum K2s M range

you're wanting to remove the main drivers? The 4 screws around the outer edge will release them, or am i misunderstanding something?
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Old 1st Aug 2021, 9:24 am   #9
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Default Re: Goodmans Magnum K2s M range

Could you post a photo of the front, showing just what you have.

Looking at a number of threads posted on various sites, there are indeed different methods used by Goodmans in assembling Magnum K2 loudspeakers.

One of which suggests the bass driver is bolted to the cabinet with the nut secured from the front, others self tapping "wood" screws are used so who knows.

Chris
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Old 1st Aug 2021, 9:49 am   #10
JimFromSurrey
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Default Re: Goodmans Magnum K2s M range

self tapping "wood" screws are what was used on the ones i removed, was some years ago though but pretty sure they were...

lay the speaker on it's back, undo the screws and the woofer will lift out (with some light persuasion if been in there 45/50 years) the wires won't be that long and IIR are soldered but it'll come forward enough for you to unsolder those and remove the driver completely
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Old 1st Aug 2021, 11:42 am   #11
Malcolm T
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Default Re: Goodmans Magnum K2s M range

Just what i was considering , woodwork, oh crap. I think the four screws around the main driver might be the key , can,t figure why they would glue it as a complete assy but i do understand costs in production, but surly not a Goodmans .
I will try the main driver and a flat screwdriver as leverage and a lot of caution first before any destructive maintenance !!!.
All because a terminal on the back has worked loose / dodgy interior connection .
Ta for the help.
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Old 1st Aug 2021, 11:51 am   #12
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Default Re: Goodmans Magnum K2s M range

Either the gasket's gone sticky, or they used some sort of sealant. Take the screws out and apply some light pressure. Keep moving the pressure around, but take some time.

Goodmans would have left a way in, or else their warranty repairs would be a nightmare.

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Old 1st Aug 2021, 11:52 am   #13
Malcolm T
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Default Re: Goodmans Magnum K2s M range

yeah i agree with that , just got it on the table now for a bash at it.
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Old 1st Aug 2021, 12:09 pm   #14
Malcolm T
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Default Re: Goodmans Magnum K2s M range

Your right Mr Moderator , just got it out by using a flat blade screwdriver between the foam surround and the chipboard support panel. The washers were stuck to the driver plastic and the foan has partially deteriorated and slightly stuck to the wood .
Its best to have a couple strips of wood handy so the driver can be rested above the cavity on these strips to get fingers under to lift away and de-solder the terminals.
A heavy ****** indeed !,
Foam is not in good condition but not falling apart , wonder if theres a better quality today or something more aligned with audio restorations ?.
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Old 2nd Aug 2021, 7:13 pm   #15
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Default Re: Goodmans Magnum K2s M range

I bought a pair of Magnum K's (earlier than yours) back in about 1969/70 and one of the bass units voice coil rubbed the magnet and the other had a damaged cabinet.
They sent me another pair, one of which also had a rubbing voice coil!
Dismantled all of them and selected the working bass units and best cabinets - eventually I was quite pleased with the units I built!
Poor kwality kontrowel.

Alan
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Old 2nd Aug 2021, 11:44 pm   #16
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Default Re: Goodmans Magnum K2s M range

The seal used between the speaker chassis and cabinet varies from one manufacturer to another. Some choosing a ring of compressible material, some neoprene and others something like draught excluder foam. The intention is to seal the box using the trapped air inside as a spring behind the bass driver thus, it is said, improving the response.

Given its a 12" unit, you shouldn't have too much difficulty using draught excluder foam or seal strip.

Chris
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Old 3rd Aug 2021, 9:21 pm   #17
Malcolm T
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Default Re: Goodmans Magnum K2s M range

Yes the foam is in need of replacement , however the rectangular foam slabs inside are in very good condition.
I have an old Gould advance audio sig gen here ( valve type , grey colour ) I was wondering about frequency checking the speaker cones with it , never done that before , how would i go about that and finding out if the cross over network is functioning .
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