JBL Sub Rattling??

[msujoshy]

I own a JBL S120PII, I've had it for like 8 months. I have noticed that it has started to rattle pretty badly, specifically the port is rattling becasue when I stick my hand in it and press down it stops almost all the rattling. Is there anyway to stop this rattling myself?

Heres a link to the sub just in case:



http://www.audioreview.com/cat/speak...1_2741crx.aspx

[audio_dude]

hi msujoshy, welcome to the forum!

ok, well, as i've always said, and you are free to bash me for this "JBL = J unkie, B ut, L oud"

so...rattling port, eh?

probably just bad workmanship, its getting late right now, so i'll ponder this tonight and give you some answers tommorow.

hope things work out!

[msujoshy]

Ha live and learn, any help though would be appreciated! I want to be able to sell the thing for a decent price.

Thanks

[Dusty Chalk]

Are you good at unbreaking things? You might want to just take it apart and put it back together -- sounds like something got shaken loose.

[msujoshy]

I'm kind of scared to do that without a guide or some tips, anybody know if such a guide exists? Also I'd be curious as to what type of glue or fastener to use on the thing.

[jpchleapas]

hi msujoshy, welcome to the forum!

ok, well, as i've always said, and you are free to bash me for this "JBL = J unkie, B ut, L oud"

so...rattling port, eh?

probably just bad workmanship, its getting late right now, so i'll ponder this tonight and give you some answers tommorow.

hope things work out!

That's a bit subjective.. My L300 and my L100t3 are not too shabby. I will agree that the new offerings since HK took over are a bit cheapened. Sadly the same can be said for most new audio sold in BB and CC stores. The vintage quality JBL speakers are pretty darn good and many hold up well over the span of time and are appreciating nicely in value. Again many of the newer JBL offerings sold today are a bit lame I must admit to be honest. The brand new higher end L-series looks better than a lot of the cheaper offerings. Sadly today people will spend $3K on a big screen TV and cry over surround speakers over $500 in total cost. Go figure?

If he can not figure out how to remove the loose port to simply apply a sealant to stop the vibrating that is a bit sad. My L300 are 140 pounds each and my L100t3 are around 55 pounds each. At least they have very stout cabinets with the L300 being outstanding in the cabinet construction quality and the huge heavy alnico drivers in them.
John

[kexodusc]

msujoshy:

Where's the port? Rear? Easiest thing to do (and it is very easy) is to unscrew the woofer - you may need a torx screwdriver if JBL tries to keep people out. Set the sub so the woofer is facing up. (you may need books or 2 x 4's or something to rest the sub on at the corners if the plate amp is on the rear -that way all the weight isn't on the amp).

Unscrew the woofer and lift it out, slowly. Check for spring clips on the woofer to disconnect the positive and negative leads, but remember which is which for reinstallation. Hopefully it has them. If not, you can desolder the wires, or just rest the woofer somewhere on the front baffle carefully.

Use plumbers Goop or crazy glue to firmly secure the port into the hole. Maybe silicione if the hole cutout is much larger than the port. You just want to make it a tight fit.
Don't allow anything to get inside the port.

This should be a very easy fix - might be as simple as gooping the outside of the port cutout in the cabinet so it doesn't have room to vibrate. It's really hard to break a sub provided you don't put a hole in the woofer or yank one of the speaker wires out or break a terminal end or something. Be careful when screwing/unscrewing. You may wish to use lock-tite or something to ensure a good seal in the screw holes - most commercial subs I've seen under $1000 use a hi-density particle board, which is fine, but isn't the most forgiving of screw threads.

Sometimes the speaker leads from the amp to the woofer are quite long, and rest against the woofer, cabinet, port, or even amp and can cause a rattle or buzz noise. IF that's the case, just taping the wires to a side or shortening them so they don't touch anything will solve this.
Let us know how it goes.

[msujoshy]

Wow thanks a lot for that step by step advice, I'm going to try to do what you've said sometime over the weekend. I'll keep you guys posted.

thanks!

[msujoshy]

Thanks a ton! I followed your directions and was suprised to find how simple the inside of the sub actually is. I ended up popping the port out then using some silicone sealant to glue it back in. It appears to be working like new again and sounds great.


Thanks,
Josh

[kexodusc]

Awesome...snap any pics while you were in there? What did have for stuffing? Polyfil? insulation? Foam? Nothing?
You could tinker with stuffings to tweak your sub if you want tnow that you're a pro.
Subs are straightforward. They're the easiest DIY speaker project - maybe next time you're ready to upgrade you'll build your own and save a ton of money.