Where to place acoustic panels for spoken voice recording?

[Thurrafork]

Hello folks

I have a very crude bedroom recording studio set up for recording my audio-description voiceover.
At the moment i have duvets messily propped up on the walls around my desk and I put pillows on conspicuous desk surfaces to try and improve the room sound.
My desk is up against a wall, so the nearest large reflective surfaces are the walls behind my desk (so, immediately behind my monitor screen) and to either side of my desk. Behind me is a bit of space (my bed, and then the far wall).
My duvet mess somehow helps create pretty reasonable sounding recordings, but recently I've come by a load of acoustic foam panels. (Ripped from a recording booth at an office where I used to record before lockdown fun).

Here's a pic. Silly set up! And you can actually see the big pile of acoustic panels in the other room!

https://imgur.com/a/dtfffzZ

I just want to get an idea of good placement for the panels.
I have lots of them so I could cover all the immediate surrounding walls if need be, but I've read that complete coverage might not actually have a good effect on the sound.
I've read about using a mirror to work out bad reflection points, but this always seems to relate to a mixing/monitoring context (looking for the monitors in the reflection) rather than vocal recording.

So where do you think I should be putting my acoustic panels?
Or maybe actually all the walls immediately around me should be covered after all?

What do you think?

Thanks

[James Perrett]

Those panels don't look particularly thick so may not work as well as the duvets that you are already using. If you want to use them then it would be best to mount them on a frame that gives some space behind them to increase their effectiveness.

[Thurrafork]

Oh no, really?
It's just over 3 inches thick and pretty tough - I know there's better out there but I thought this would be ok.
I'm going to try it anyway.
Good tip about the frame with space behind, but I'm still looking for guidance as to actual placement.
Any thoughts?

Thanks

[Hugh Robjohns]

I'd place them wherever there's a hard surface that can bounce your voice sound back into the microphone. So that means the side walls of your alcove, the back wall and possibly the ceiling of the alcove, and then on the desk and in front of the screen. (Obviously these last positions will need to be removable -- or you could just keep using the duvet and pillows for those roles!)

Mounting on a frame that spaces the fixed panels away from the wall surface by their own thickness will usefully lower their effective frequency range, as James has intimated.

[Thurrafork]

Thanks very much!
When you say 'so that means the side walls of your alcove, the back wall and possibly the ceiling of the alcove', do you mean complete coverage of those areas?
Thanks

[Hugh Robjohns]

No, just the primary areas that will reflect towards the mic.

[Thurrafork]

Forgive my ignorance, but where are these 'primary areas'?
Where the poster is at the moment? But a larger area? Or are smaller 'spot' areas more effective? (so about the size of the poster there)?
The corner areas? The corners from the ground up, or just the 3axis corner areas at the top?
Just head level on the side walls?
Just a spot directly above my head on the ceiling?

See? I really have no idea about this stuff!

Thanks

[Martin Walker]

When you say 'so that means the side walls of your alcove, the back wall and possibly the ceiling of the alcove', do you mean complete coverage of those areas?

It certainly won't do any harm - on an area as small as that I'd be inclined to cover it all with trapping.

Martin

[RichardT]

In my experience, there’s no substitute for experiment! Try out a few of these ideas and see how well they work. You can even try sticking two foam panels together to get greater thickness.

[Thurrafork]

Some good replies here already!
But any more information/advice would be greatly appreciated!

Thanks

[BWC]

Forgive my ignorance, but where are these 'primary areas'?

The mirror points.

I've read about using a mirror to work out bad reflection points, but this always seems to relate to a mixing/monitoring context (looking for the monitors in the reflection) rather than vocal recording.

In either context, sound still takes the same path as light. The only difference is that it's traveling from mouth to mic, rather than monitors to ears.

...on an area as small as that I'd be inclined to cover it all with trapping.

I think Id also be so inclined.

..so I could cover all the immediate surrounding walls if need be, but I've read that complete coverage might not actually have a good effect on the sound.

Some instruments sound too dead without some amount of reflected sound reaching the mic, but for your purposes that shouldn't be a problem.

In my experience, there’s no substitute for experiment! Try out a few of these ideas and see how well they work.

Yep, time to stop reading (for a little while), and start experimenting. If your experiments raise more questions, come on back and ask.

[Thurrafork]

Good advice, thank you!

Yes, I just need to get cracking.

My first experiment is to get the panels up in a way which won't damage the walls.
I'm going for Command Strips.
Anyone tried this method?

Thanks

[Tomás Mulcahy]

Yes they will hold up those foam panels but as James said they won't work as well as the duvets. Most likely it will sound worse because they have less LF absorption than the duvets. Ideally, build the classic Rockwool RW3 panels.

[Peevy]

My first experiment is to get the panels up in a way which won't damage the walls.
I'm going for Command Strips.
Anyone tried this method?

You could use the tried and tested Soundonsound method which is to stick a CD to the top of the back of the tiles, then you can hang the tiles from a hook on the wall (or small panel pin nails)

(The panels hang by using the hole in the CD)

If you use small panel pins, they won’t cause hardly any damage. Or use command hooks attached to the wall (more expensive!).

[Thurrafork]

Even though panel pins would only cause minimal wall damage, I think I'm going to go with Command Strips - especially if I'm likely to find that these panels are less effective than my current duvet mess.

On that subject, I know the duvets would be better at absorbing lower frequencies than the acoustic panels, but I am only recording spoken voice - nothing goes terribly low - am I really likely to find the duvets better?

Thanks

[Tomás Mulcahy]

Yes. Duvets simply have greater absorption. You could record white noise and/or sin wave sweeps into your vocal mic with each set up to compare.

[Thurrafork]

Right!

Now I'm considering abandoning the foam, and just building a pvc pipe frame to support my duvets with slightly more elegance!
Anyone done anything like this?
I've seen a few youtube vids about it, but I often wondered if some kind of unpleasant resonance might somehow build in all that piping.

What do you reckon?

[Drew Stephenson]

If you're thinking of building, it's probably worth rethinking building some broadband traps using rockwool.
They really are pretty straightforward to make, can look very tidy, are very effective, and can be moved into any future room you use.

[Hugh Robjohns]

Now I'm considering abandoning the foam, and just building a pvc pipe frame to support my duvets with slightly more elegance!

If you don't want to fix anything to the wall, build a simple three-sided wooden frame to sit in the alcove from the desk or floor and support the foam on the frame. The frame will space the foam from the wall and extend the absorption bandwidth to a lower frequency, too.

I often wondered if some kind of unpleasant resonance might somehow build in all that piping.

Yes, and especially if you leave the ends open. Seal the ends and/or stuff some foam in to damp and resonances.

[RichardT]

If you're thinking of building, it's probably worth rethinking building some broadband traps using rockwool.
They really are pretty straightforward to make, can look very tidy, are very effective, and can be moved into any future room you use.

I think this is exactly right!