DIY silencer.

**Uv123_4** · 19-07-20, 02:10 PM

I am thinking about trying to make one with my old carbon filter has anyone tried anything similar I have been looking at @ironman and saw the ones you can buy. I was thinking about like a sponge for washing cars replace the carbon with sponges like the ones you buy. Can’t be much different. Will have to put something on outside to block all the small holes in filter I think. Thanks for any input.

**TotalPlantPot** · 19-07-20, 06:19 PM

I've been thinking about this issue a little, but only as a thought experiment.
I have a reasonable (education)background in sound engineering - though i never found work in the field.

There are commercial silencers available they appear to be sheet metal / steal ducts with standard "egg box" patterned foam inserts.

There are two types of noise from my grow;
Vibration from fans & pumps You can buy anti-vibration feet and/or rubber mounts to reduce vibration transmission which work really well and very cheap!
&
Moving air this is the hardest one for me to battle as the range of frequencies moving air produces is right across the board.

There are certain shapes and materials you can use to combat some frequencies, but there is not one shape or material that can dampen all.
Also consider introducing anything into your system will ultimately reduce your airflow and may cause the noise to be amplified at a different section in a different frequency.

I've not done any testing of these silencers, i dont even own one. However there is a basic rule when it comes to fans and moving air, larger slower fans ( with larger diameter ducts ) will always be quieter than smaller faster fans.
If fan noise is something you are concerned about , choosing the biggest diameter fan and duct you can get away with and turn the speed down will give you the best airflow results for a lower sound level.
In my opinion spending $100 more on a better(larger) fan would work out quieter than spending money buying or making a silencer.

If you still fancy making your own , I would buy some acoustic foam panels from amazon (packs of 10 or 12 are $20 ) experiment with lining the inside of a cardboard box with them then having your air run through the box, while the over all sound volume might not change much, you may find you prefer certain arrangements based on your own subjective hearing.

Depending on your setup, you could even get a bulk pack and sound dampen an entire wall, or the entire room!

**Uv123_4** · 19-07-20, 07:04 PM

Originally Posted by TotalPlantPot

I've been thinking about this issue a little, but only as a thought experiment.
I have a reasonable (education)background in sound engineering - though i never found work in the field.

There are commercial silencers available they appear to be sheet metal / steal ducts with standard "egg box" patterned foam inserts.

There are two types of noise from my grow;
Vibration from fans & pumps You can buy anti-vibration feet and/or rubber mounts to reduce vibration transmission which work really well and very cheap!
&
Moving air this is the hardest one for me to battle as the range of frequencies moving air produces is right across the board.

There are certain shapes and materials you can use to combat some frequencies, but there is not one shape or material that can dampen all.
Also consider introducing anything into your system will ultimately reduce your airflow and may cause the noise to be amplified at a different section in a different frequency.

I've not done any testing of these silencers, i dont even own one. However there is a basic rule when it comes to fans and moving air, larger slower fans ( with larger diameter ducts ) will always be quieter than smaller faster fans.
If fan noise is something you are concerned about , choosing the biggest diameter fan and duct you can get away with and turn the speed down will give you the best airflow results for a lower sound level.
In my opinion spending $100 more on a better(larger) fan would work out quieter than spending money buying or making a silencer.

If you still fancy making your own , I would buy some acoustic foam panels from amazon (packs of 10 or 12 are $20 ) experiment with lining the inside of a cardboard box with them then having your air run through the box, while the over all sound volume might not change much, you may find you prefer certain arrangements based on your own subjective hearing.

Depending on your setup, you could even get a bulk pack and sound dampen an entire wall, or the entire room!

I have my old carbon filter. It’s only an experiment If it don’t work then it don’t matter I just think if even it helped a tiny bit I’d be happy. Just playing about and seeing if anything works well. Would be good advice for other people too.