DIY Acoustic Panels

Freebird

Musicwolf

This is posted as a joke, right?

Freebird

Musicwolf said:

This is posted as a joke, right?

He's got 1.4m subscribers, and 2.2m people have watched the video, so he's either good at jokes or he's good at DIY  

Musicwolf

And utterly shit at physics.  The numbers of followers doesn't make what he's saying correct.  After all, nearly 63m Americans were dumb enough to vote for Trump in 2016 and god knows how many Tory supporters will vote for Boris.  Sticking to the facts has never been an obstacle to gathering followers.

Freebird

He does a voice test at the end. There is some difference, but I don't know if it is the right kind of difference for you. I hang a heavy duvet behind my mic and it works quite well, so I wouldn't knock anything until you try it.

robinbowes

Oh dear.

Robin Bowes, B.Eng(Hons) Electroacoustics.

Freebird

robinbowes said:

Oh dear.

Robin Bowes, B.Eng(Hons) Electroacoustics.

Is that a no? 

Could you explain the difference in the recorded voice at the end?

robinbowes

Freebird said:

robinbowes said:

Oh dear.

Robin Bowes, B.Eng(Hons) Electroacoustics.

Is that a no? 

Could you explain the difference in the recorded voice at the end?

I commented before watching all the video.

The panel he came up with is actually not bad - basically, you need density to absorb sound, which multiple layers of towels has. It would be better if it were a little thicker perhaps.

A "proper" acoustic panel would use something like Rockwool RW3 in a similar frame, so he's not all that far off.

As he discovered, the "special acoustic foam" he compares to at the end is not the same sort of thing at all.

R.

John_P

He’s absorbing some of the higher frequencies so it sounds dry and less echoey which might help a bit with vocals but there isn’t enough mass in the absorbers to deal with the low mids and bass.  
 Maybe combined with some corner bass traps it will more effective.

robinbowes

John_P said:

He’s absorbing some of the higher frequencies so it sounds dry and less echoey which might help a bit with vocals but there isn’t enough mass in the absorbers to deal with the low mids and bass.  
 Maybe combined with some corner bass traps it will more effective.

Bass requires a different approach, eg. resonators, or diaphragmatic absorbers.

R.

Freebird

robinbowes said:
The panel he came up with is actually not bad - basically, you need density to absorb sound, which multiple layers of towels has. It would be better if it were a little thicker perhaps.

A "proper" acoustic panel would use something like Rockwool RW3 in a similar frame, so he's not all that far off.

Thanks for the info.

Freebird

John_P said:

He’s absorbing some of the higher frequencies so it sounds dry and less echoey which might help a bit with vocals but there isn’t enough mass in the absorbers to deal with the low mids and bass.  
 Maybe combined with some corner bass traps it will more effective.

Yeah, bass is another story. I use headphones quite a bit, and room corrected (at the listening position) nearfield monitors at low volume, so there isn't much bass moving around. My main interest is deadening the room when I use the condenser mic. My current setup is a SE Electronics Space reflection filter in the front, and a duvet at the rear, so I am always open to new ideas. Maybe I should checkout the Rockwool option too, but I know it can cost quite a bit to do a proper full room treatment job.

Musicwolf

What he's done is to produce a fairly inefficient absorber which will operate at higher frequencies.  He could have achieved much the same effect by hanging heavy curtains or duvets.  He's done nothing to tame the bass and low mids so the room will sound boxy.

When we say we are absorbing sound we mean that we are converting the Kinetic Energy of moving air molecules into minute amounts of heat.  When a sound wave reflects from a surface the pressure at the boundary is a max (sound waves are compression waves), the air movement is zero.  The maximum air movement (max Kinetic Energy) occurs one quarter wavelength away from the wall.

This is where your absorber will work most effectively.  The usually approach for DIY broadband absorbers is to use something like Rockwool RW3, which has a density of 60kg m-3, with a thickness of 100mm.  You cover this with 'breathable' fabric (I recommend Cara fabric as it produces a professional finish) and mount in a suitable frame (loads of 'how to' vids out there depending upon your DIY skills).  You then mount the panel so that it sits away from the wall (say another 100mm).  This arrangement will give you something that will work down to around 450Hz.  Mounting across a corner (wall:wall, wall:ceiling) increases the depth so the absorber will work at lower frequencies.

Rocker

For a low cost, he achieved a lot.

WiresDreamDisasters

Yeah I wouldn't do it that way.

Freebird

Rocker said:

For a low cost, he achieved a lot.

What that chap has done is build something at a very low cost for microphone recording, that sounds better than nothing.

I get the whole room treatment thing, but where do you start and where do you stop? Like all things audio related, you can soon end up like a dog chasing it's tail, and without any tax write-offs the expense can quickly get out of hand. I'd probably feel compelled to continue until I had spent thousands to achieve a professional level, and then I'd go on to build an extension to house it all, as my current room isn't really suitable to begin with.

It's all about tradeoffs, and for some people a poor man's sound absorber made out of household junk may be just the ticket. I've purposely gone mostly digital with a Kemper and e-Drums, etc., so that I can cut out the room. If I ever made any release quality music, I'd probably redo the non-digital stuff like vocals and drums in a studio anyway, and have it professionally mixed and mastered.

In an ideal world I would Iove to have a purpose built and professionally treated music room, but it's hard to justify when I look at my current requirements, which is mainly songwriting and recording demo ideas. I'm guessing somebody who is agonising over the purchase of a £100 audio interface may feel the same way.

Freebird

WiresDreamDisasters said:

Yeah I wouldn't do it that way.

As a matter of interest, how would you do it? I'm looking to do something reasonably basic, but as mentioned above I don't want it getting too out of hand.

PS have you checked out Modo Drum? They are using modelling instead of samples, and if Modo Bass is anything to go by, it will be interesting to see if they have made any progress.

WiresDreamDisasters

Freebird said:

WiresDreamDisasters said:

Yeah I wouldn't do it that way.

As a matter of interest, how would you do it? I'm looking to do something reasonably basic, but as mentioned above I don't want it getting too out of hand.

PS have you checked out Modo Drum? They are using modelling instead of samples, and if Modo Bass is anything to go by, it will be interesting to see if they have made any progress.

Modo Drum looks to use a combination of samples and physical modelling, but I don't know much more about it. I would guess they've sampled drums, but done it very quickly in order to get different types of transient profiles, and then they're physically modelling the tail and resonance. But I really have no idea. Looks nice though!

As for panels. This is how I did mine, more or less.

Rocker

These panels may be OK in a dedicated recording studio but they have no place in a domestic room in a house or apartment.  They look awful and take up a lot of space in the room.  Most modern living spaces are very small as it is and, without a detailed analysis of the room before treatment, buying or making these things is a gamble at best.

Simply put, IMHO, professional knowledge and expertise is needed if you are planning on going down this route.  

Freebird

Rocker said:

These panels may be OK in a dedicated recording studio but they have no place in a domestic room in a house or apartment.  They look awful and take up a lot of space in the room.  Most modern living spaces are very small as it is and, without a detailed analysis of the room before treatment, buying or making these things is a gamble at best.

Simply put, IMHO, professional knowledge and expertise is needed if you are planning on going down this route.  

It's a conundrum, and that's why I mainly focus on stopping the crap from getting into the microphone, as that totally ruins everything.

Lestratcaster

I've just had some panels made and installed in my newly converted garage. Was advised at least 100mm thickness, and its made a huge difference to the echoiness. I made the silly mistake of trying to use the cheap foam square stuff (I think it was only 25mm thick) and it turned out to be a disaster.

Like @WiresDreamDisasters Youtube link I had mine made of a wooden panel with RS3 Rockschool stuffed inside then covered with an acoustic fabric cloth.

Its not a mixing/production room so its enough for what I need it for, to stop the sound bouncing off the walls!