stranbge sub noise

[johnnyc 10+ year member]

Hi guys,

Is my sub blown?

Juts been doing some work on sons. Installing a new sub and amp and making the exisitng amp for his 6x9 rears.

Upon first hearing the sub it sounded rattly, if I gently touch the foam thn the sound is much deeper and fine.

I have taken the sub out of the enclosure and cannot see any issues with it.

What could be the problme.

Thanks

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[Sub Woofin 10+ year member]

can you describe the noise?

 

[johnnyc 10+ year member]

I can only describe it like a rattle, as if something is loose. As sson as a i gently touch the foam the rattle goes and the sound firms up to lower sound.

As sson as I heard this I took the sub from the enclosure to have a visual but to my eyes everything seemed ok. Just in case the amp was the cause (unlikely) I connected this to the old sub and all was fine.

Thanks

 

[disturbed471985 5,000+ posts]

U check all the glue joints? Possibly the cone coming seperated from the basket? Being as if u push down on the surround it stops? Spiders still glued well??

 

[johnnyc 10+ year member]

I will whip it out and have a check. If there is the need for more glue is there a best way to appraoch it?

 

[johnnyc 10+ year member]

OK, have sub out of enclosure. Have check the foam edge joints and all appears fine. However...

If if gently press on the foam for half of the edge I can hear a slight rubbing noise. Like a papre/card rubbing. Around the other half of the foam there is no noise.

If I tap gently on the foam (where I get the rubbing noise, say at 6 oclock) then I can here the virbrating but go to the opposite 12 oclock then I have no noise.

It has been some 20 years since I tinkered with car audio so sorry if I am a bit vague..

 

[johnnyc 10+ year member]

Interestingly enough I have found someone else who ahd the same issue withe sae driver make. As ever though there is no clear resolution.

Thread Slight rattling on subwoofer cone | dj forums - The Worldwide DJ Community | BoardReader

 

[VisceralSound 10+ year member]

Do you have a Digital Multimeter? You can check if its blown by using the DMM, most cases if theres "rubbing" the coils blown and is rubbing.

With the sub out, maybe try pushing gently upwards underneath the cone and look at the joint where the cone-spiders meet if theres any gaps that could be an issue too.

 

[johnnyc 10+ year member]

ok, can you just explain "cone spiders"

 

[VisceralSound 10+ year member]

The tan object is the spider, and its glued to the cone

 

[johnnyc 10+ year member]

spider is fine and used very small pressure to test.

So when I gently placed the sub on the floor I get the same noise as when I gently tap the cone....

with the multi meter how can I check it?

 

[VisceralSound 10+ year member]

What configuration is the sub? D2 D4, S2 S4 with all the wires taken out of it, put the DMM to the "Ohms" setting and put the +/- leads to the +/- of the woofer on each coil, depending on the config it should range from 4.0, 2.0 etc etc.

 

[johnnyc 10+ year member]

for sure its single, not to sure on the rating though.

sub is out of enclosure so I will get a meter on it tomorrow (UK here).

Will post back.

 

[VisceralSound 10+ year member]

Look on the magnet/under the subwoofer it should say what it is (if not post what your subwoofer is and I'll look it up for you, or I guess when you meter it it will give you numbers)

 

[johnnyc 10+ year member]

make is edge, basement brand from UK.

12"