Hi,

I'm starting to make a homemade silencer for my cupboard, yet had a few queries to throw to you all.

I'm a 10cm by 50cm plastic tube which will have holes drilled in it, then surrounded by the insulation from some insulated ducting.

I was just wondering what sized holes should i drill in the tube and how far apart should they be?

also had an idea, to absorb all diff sounds would it be an idea to drill holes of different sizes all over the tube?

Monkey

This might be useful-Click me

Yeah looks good,

however he goes into no detail about the size of the holes.

I was wondering if there is any noise science behind the size of the holes?

no sceince i used 8mm drill bit and just drilled as many holes as possible also it was mentioned in a thread on one of these home made jobbies if some one could use cotton wool instead of insulation material the answear to that no insulation material does not get affected by humid air also i modded mine by cuttin the tube agfter it came out of the tubs one cut on the top to half way down then one cut three inches away on opposite side of tube again only half way through then put carboard inserts into the cuts to make a baffle to stop the whoosh of air works a treat total cost for filter £4.50 tine 3 hrs work result pisses all over the proper one i bought costing £40

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As many holes as possible is what I tried to do

Just thought, could you not just have a bit of tubing at both ends of the silencer, then get chicken wire and wrap it around the two tubes to create a cylinder shape then pack the insulation around this. This would be like drilling millions of holes in a full length tube. Would that not work better.

I created my own silencer using some cheap tumble dryer ducting which is really easy to put holes into,

Any ideas on the technique in the post above

Thought about that way too, feels like it might work - only one way to find out

True and I guess it would be a hell of a lot easier than drillin into plastic pipes all day.

hi
if you look further in the thread u can see i changed it ,and use ducting as did Blabb
acoustic ducting just has loads of pin prick holes ,so i just use a screw driver to make holes

drilling the plastic pipe is hassle

Aye, I got jiggy with a stanley kinfe and covered the ducting with little square holes. Quite theraputitic if I remember rightly

Thats what they do (paintball silencer build) with other types of silencer. the scanned guide at the bottom shows a bit of chicken wire like you suggested.

Maybe worth a try?

bAb

Amazing, great link buildAbong!
At the bottom of the page where it shows one being made...you can see the inside tube with drilled holes in, which is then wrapped by the chicken wire, then foam then hard plastic. It would seem to me that the chicken wire is simply used to stop bits of the foam from entering the channel through which the bullet(paintball) travels. Though of course it may do it's bit to help reduce noise.

From other ideas on here I used tights to cover the holes in my silencer to stop the insulation being sucked through.

I eventually made my silencer in Jan of this year. The making of it is within my growdrobe construction diary (link to the specific post below).

http://www.uk420.com/boards/index.php?s=&a...st&p=832930

I will be doing some sound testing towards the end of my build and shall test the noise levels with and without the silencer, and may make modifications to the silencer if needed then. (maybe add thicker foam insulation and hard plastic outer tube).

silly question but here goes

why have the silencers got a hard case surrounding them ? why not leave that off and just let the air bleed away threw the walls and the open end? wouldnt this quieten the outlet more this way ?
i know the shop brought ones will have a case to be pleasing to the eye , but is it needed ?

sorry if this has been covered and ive missed it
cheers

i bought one, 6 inch duct, and unlike a vehicle silencer there are no baffles etc. all it is is a 6 inch duct fitted inside a larger one with some kind of sound proofing in between. so for my smaller extracter i made a silencer simply by fitting some over size ducting over the 4 inch ducting and stuffing the gap with some loft insulation. it makes an incredible difference even though there is no baffle or holes etc.