How to know for sure if magnet has partially detached or cracked

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majabusic

Member
2019-12-02 4:56 pm
I know this is DIY forum but i figured you guys here might be able to address my concern even if my case doesnt involve DIY project and its just cheaper prebuilt system

Sorry if its wrong category but i figured that you might be able to help here

so, i have recently got logitech z906 5.1 speakers for my new PC and few weeks later as i was moving stuff around i temporarly set rear speakers on bookshelf speaker stands that are little bit shorter than avrage PC desk and while i was moving some stuff i accidentally pushed one rear satellite speaker off the stand and it fell on the floor, only visible damage is small scrach on THX logo one one scrach on the scew (talking about this screw here untitled — imgbb.com) because there was something small metal on the floor where it fell on carpet.

Now im afraid that because of that fall magnet might have some cracks or might partially detached or slightly shifted, so far i havent noticed anything unusual or any noticalbe change in audio quality so my question is, if magnet shifted even slightly from fall would the difference be noticable and is there any way to confirm if magnet shifted, cracked or detached partially without opening it up, would it change the sound enough to confirm if its damaged?

I know that probably nothing happened since i didnt notice any distortion or noticable difference (my hearing isnt perfect but i dont notice any difference so far) but my OCD is killing me and i really need to know if magnet shifting even slightly would make a noticable difference, im afraid that maybe it made some difference but not enough for me to notice and now my OCD is killing me, if i cant find out for sure if there is any damage done i will probably end up just buying new set just to get rid of frustration that my OCD is causing me now

I know this forum is mostly about high end speakers and custom builds and im know z906 are far fom super high quality audiophile speakers but i like them and they are more than enough for ocassionaly playing music on my pc or when i have some friends over so we can play videogames without headset so if anyone can answer my question and adress my my concern about this it would be great

Thanks in advance
 
Galu

Galu

Member
2018-04-17 6:50 pm
It is extremely unlikely that the magnet has shifted as it is strongly held in place by metal plates - see attachment.

Even if you could look at the driver you wouldn't be able to see the magnet because it has a shielding can around it.

If you want to see what's inside the enclosure then look at this video:

YouTube

If the speaker sounds OK, then there is nothing wrong with it - chill! :cool:
 

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JMFahey

JMFahey

Member
2009-03-18 7:32 pm
Buenos Aires - Argentina
im afraid that because of that fall magnet might have some cracks or might partially detached or slightly shifted, so far i havent noticed anything unusual or any noticalbe change in audio quality
Click to expand...
If magnet/polepiece shifts it is VERY noticeable because it pinches the voice coil, cone freezes , you have NO bass, NO mids and highs soundpinched and nasal, NO WAY to mistake it.
So nothing happened.

extremely unlikely that the magnet has shifted as it is strongly held in place by metal plates
Click to expand...
Sorry but quite the opposite.
As shown, the bottom plate + polepiece are NOT attached to the frame but *floating* and their weight tends to tear away magnet from frame.
Magnet itself is only glued to front plate, and that´s iffy because plate is smooth iron but much worse,magnet is ultra smooth (actually polished) ceramic material, zero pores, and very rigid, think porcelain ior glass instead, any *sharp* hit inn the proper direction, worst possible would be speaker falling backwards, all the weight tearing magnet from frame which is bolted to front panel, magnet is free floating, will make epoxy joint fail and separate.
 
M

majabusic

Member
2019-12-02 4:56 pm
chris661 said:
If it sounds fine, it's probably fine.

The way to test would be to pull the driver for inspection. Next best is to make sure it reproduces LF tones without any buzz from coil rubbing.

Chris
Click to expand...

I guess i need to connect it to some external amp to test LF, those are small satellite speakers and amp in the subwoofer filters low frequency from them and redirects them to subwoofer
 
M

majabusic

Member
2019-12-02 4:56 pm
Galu said:
It is extremely unlikely that the magnet has shifted as it is strongly held in place by metal plates - see attachment.

Even if you could look at the driver you wouldn't be able to see the magnet because it has a shielding can around it.

If you want to see what's inside the enclosure then look at this video:

YouTube

If the speaker sounds OK, then there is nothing wrong with it - chill! :cool:
Click to expand...

So far it sounds OK, havent noticed anything wierd yet
 
M

majabusic

Member
2019-12-02 4:56 pm
JMFahey said:
If magnet/polepiece shifts it is VERY noticeable because it pinches the voice coil, cone freezes , you have NO bass, NO mids and highs soundpinched and nasal, NO WAY to mistake it.
So nothing happened.


Sorry but quite the opposite.
As shown, the bottom plate + polepiece are NOT attached to the frame but *floating* and their weight tends to tear away magnet from frame.
Magnet itself is only glued to front plate, and that´s iffy because plate is smooth iron but much worse,magnet is ultra smooth (actually polished) ceramic material, zero pores, and very rigid, think porcelain ior glass instead, any *sharp* hit inn the proper direction, worst possible would be speaker falling backwards, all the weight tearing magnet from frame which is bolted to front panel, magnet is free floating, will make epoxy joint fail and separate.
Click to expand...

These are satellite small speakers from logitech z906 5.1 PC speakers so there is really not much bass coming out of satelites, everything gets crossed over to subwoofer but i did try turning down the subwoofer all the way so i can hear only satellites and i tried playing some music and turned it up really loud and i havent heard anything suspicious from the satellite that fell down, i was even able to see the speaker move up and down when drums hit so it probably means cone hasnt locked up and its probably fine
 
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