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Sub Vibration Noise Problem - Click HERE for Original Thread
hernanstafe
I've recently built a vented sub 10" cabinet, and when i put the vent tubes in i hear a horrible noise like the wood vibrating. The box is really strong i put a lot of screws in it so it didn't vibrate but something still does vibrate, the vent tubes are not the problem. I was wondering if it's needed to cover the inside of the cabinet with some noise suspension material or it's not needed, i really don't know what to do:(i tried holding the cabinet firmly with a friend but it still vibrates. Any ideas?
Volenti
How is the driver attached to the enclosure? did you use a gasket of some sort? There is a lot of pressure in the enclosure especially at the tuning frequency and this can make the sub move on it's mounts even if it seems solid by feel, same goes for the port.
hernanstafe
the speaker is mounted using 8 screws with nuts, it looks and feels strong. The box has lots, and i mean LOTS of screws everywere. About the vents, when i put a tube in the vent, holding it with my hand not touching the enclosure, you can still hear the vibration noise, even when i put no tubes at all you can hear a slight vibration noise i assume coming from the inside. There are no loose parts inside at all.

Oh, the speaker comes with a rubber gasket!! so i don't think that's it
audiobahnkid592
Try putting a gasket behind the sub it self. In between the wood and sub can vibrate when it is playing.
hernanstafe
it has a gasket, the speaker border is covered with a rubber gasket that goes between the wook mount and the speaker itself.
audiobahnkid592
Is the speaker itself possibly damaged?
MJL21193
Hi. What kind of wood is it made from? Cheap plywood can have voids inside with loose material that buzz and drive you crazy. MDF is the best bet for subs.
Also are your vents large enough? High speed air can produce a sound as it goes though the port.
hernanstafe
the speaker is not damaged, when it's off the box it sounds just fine. The vent size...well that might be a problem. When i take the connectors on the back of the cabinet off there a 2.5" whole, the sound changed dramatically but the vibration seems to dissappear. Like i said, the sounds changed and it's not so good. I can show you the cabinet plans, and pictures if you guys want
MJL21193
Is the connector plate rattling against the box? Is there a gasket behind it? It doesn't take much.
richie00boy
How much is the driver moving? Sounds like either the driver may not like moving so much, or you have a too-small vent diameter.
hernanstafe
well the driver moves quite a lot, but even at low volume it vibrates. I'm almost sure it's not the driver, cause it sounds like wood vibrating. The sound can be compared with the sound an enclosure makes when the back panel is made of thin wood and it vibrates in the center. It sounds like that, except this wood is REALLY thick.
Should i cover the inside with some sound-prove material?
MJL21193
Once again, what wood is it made with? One layer? Two layers? It's not a hugh driver, so there is some construction problem.
I have 2 18" in a 60litre sealed box driven by 600++ watts peak and there is not a peep of sound ( except walls, floor, ceiling , furniture, the Earth shaking, rattling).
hernanstafe
Well idk the name of the wood (in english, i speak spanish here), it's artificial, it's made of wood dust mixed with glue and pressed, it's used to make speakers here, i have 2 15" boxes made with it and they work just fine, so i seriously doubt it's the wood
MJL21193
Yeah, that would be MDF. You mentioned a lot of screws. Screws can split MDF along the edge. Did you use lots of glue? Have to build these things like submarines or they'll talk to you.
hernanstafe
Well that's one thing i didn't do. I didn't use glue...can that be it? the screws are really tight tho
MJL21193
I generally avoid screws in MDF. I use a nail gun with long thin nails and TONS of glue. What you could do if you have clamps big enough is to clamp it and then try it. If it stops rattling then you have found the problem.
hernanstafe
why not screws if i may ask?
MJL21193
Like I said before, screws will split MDF even if you drill the correct size pilot hole. When I do use them I am careful to keep them far from the end and try to keep them spaced apart. Yellow carpenters glue makes an extremely strong joint, especially if the parts fit together well.
hernanstafe
got it! i'm gonna see what i can do. thanks a lot for that! the sad part is that i'll have to dissasemble it:(:bawling:
richie00boy
I'd say the problem is that you haven't glued it. Glue will help seal the box.
hernanstafe
yeah i'm gonna undo the box ,glue it and build it back; today i started college again so my time is limited to work in this:( but i'll get my hands on it as soon as i have time and let you guys know!! Thanks to everyone for your help!!
mikee55
Hello all,just read this. If he hasn't glued his box and it seemed like he didn't know he had to do that, and everyone says loads or tons of glue. I just wanted to point out that too much glue makes a weak joint. Does he know that? If you screw mdf, it helps to pinch pieces together whilst the glue sets. Theres no need to overtighten the screws, and make a tight won't come undone fix. Thats what the glue is for. If you use clamps etc, you can just glue, without nails or screws.

I have'nt looked, but a collaberation of assembley techniques could be stickied. A list of glue types, hints and tips from any clever Chippies amongst us all. I spent a year studying fine furniture construction, about 10 years ago, and have forgotten a fair bit of what I learnt and yes, theres plenty of info on the web. But, what works best for solid subs?

Cheers mikee55:D
richie00boy
Good point Mike, I often see people saying to use loads of glue, which is wrong. Also the best glue to use can depend on how accurate the cuts are, amongst other things.
MJL21193
When I say tons of glue, I mean a lot of glue, more than a novice constructor would normally put on the joint, because the excess will squeeze out. It goes without saying that you will use clamps to hold the parts tightly together while the glue dries- we are building high quality loadspeakers here!
Too much glue DOES NOT make a weak joint. Sloppy cuts, misinformation and most of all impatience make weak joints.
Without going into a whole symposium on proper construction techniques, here are a few pointers from a journeyman carpenter who's been working in the trade for 25 years:
1 - make your cuts as staight and true as your ability allows. If there is a gap between the pieces, try to correct it.
2 - When it comes to wood, and wood products(MDF, plywood, particle board) there are only two types of glue I will use: Yellow carpenter's glue (PVA) for all interior work, and polyurethane glue for exterior or wet applications. Both of these will form the strongest, permanent bold possible. Both of these glue work best when applied liberally to the tight fitting joint and clamped till dry. As I said earier, the excess will squeeze out. If you find that your joints are not tight and you lack the ability to fix it, use of the polyurethane glue will actually bridge the gap, as it foams during the drying time. It can easily fill an eighth inch gap( 2 MM).
3 - I love screws, but screws will split egde grain if the correct size pilot hole is not drilled first, and even with the pilot hole screws will most likely split MDF, which is very weak along its edgegrain.
Just some sound advice from someone who does it for a living.
mikee55
It can go here

http://www.diyaudio.com/forums/show...&threadid=98592

:) ;)
MJL21193
Mike: It did:)

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