Thinner alternative to rockwool

Axe_meister

Looking to build a bit of sound treatment, what are thinner alternatives to rockwool with similar or better audio properties?

Sporky

Sheetblok?

https://auralex.com/sheetblok-sound-barrier/

Whistler

Use Sheetblok or similar products to help with isolation (aka soundproofing).

Use rockwool or similar as acoustic treatment (reduce how much sound bounces around within a room).

Soundwaves have lengths based on their frequencies. The normal recommendation is 20cm minumum in front or walls or below ceilings. This can be halved if you use 10cm with a 10cm gap behind the panel(s). This will provide reasonable damping down to 200Hz (G, an open 3rd string is 196Hz).

If you use a thinner rockwool or alternative, such as open-cell foam then you will only be treating down to a higher frequency. For example, a 2cm panel with no gap behind the panel, whether rockwool or foam, will provide damping down to around 5kHz, so only the higher treble content will be reduced, giving you unflat response and a muffled sound - a cozy sound for radio (hence the plethora of pyramid foam panels in radio stations) but pretty much useless for music.

Back to your question: what thickness of rockwool are you thinking of such that you want it to be thinner?

Musicwolf

I'm right in the middle of a major makeover for my little home studio, which includes new / additional panels.

As stated above, Rockwool panels spaced from the wall will give you the best performance and Rockwool RW3 (60kg m-3) is generally preferred as it gives the best compromise between absorption and rigidity, however.  It's an absolute bugger to get hold of in small quantities these days with most places asking delivery costs of c£90 inc VAT (about twice the cost of a single pack).  I'll be re-using some of my RW3 but I've ordered RWA45 (45kg m-3) 75mm thick (6 1200x600mm slabs in a pack) to make up additional panels.  Acoustically there are schools of thought which say that RWA45 is actually better, particularly at the higher frequences, but requires additional support as it is more flexible.

The sheetbloc lined in the previous post can be used to extend the low-end effectiveness of a Rockwool panel as described here.

https://www.soundonsound.com/techniques/studio-sos-building-diy-vocal-booth 

https://www.soundonsound.com/techniques/studio-sos-making-small-room-sound-good

I'll be employing this method in my rear corner trap which will be 300mm deep in total.

Axe_meister

The room is small and a very odd shape, in fact that are no real parallel walls. It's a loft space so sloped ceilings with only about 1m flat walls in the eves. The problem is even a regular sheet of rockwool in a frame (as per most of the youtube vids), will severely eat into head room (I can just about stand in the centre of the room) 

Sporky

Whistler said:

Use Sheetblok or similar products to help with isolation (aka soundproofing).

Use rockwool or similar as acoustic treatment (reduce how much sound bounces around within a room).

Try hanging some sheetblok 10cm from a wall - while it is indeed intended for soundproofing, it works by absorbing soundwaves, so positioned right it can be used as an absorber.

octatonic

Sheetblok works to a degree.
Really though you need to ring out the room to find out what you need to do.

GIK acoustics have a free assessment process that is work doing.

Musicwolf

octatonic said:

Really though you need to ring out the room to find out what you need to do.

If you haven't already done so, download Room EQ Wizard and run a test on your space as it stands.  There are YouTube vids to guide you through the process and to help you understand the results.  Once you know the problematic frequencies you can work work out where you need to apply treatment for best results.

The GIK room calculator will, very quickly, give you an idea of the number of panels that you would require.  Unfortunately for you, it is based on a rectangular room.  But it will give you an idea as to the magnitude.

You really cannot beat the laws of Physics.  Trust me, I know.  I spent three years getting my Degree in the subject, if I could have beaten it I wouldn't have had to spend so much time in lectures.

The bugger of it is, the smaller the space the more treatment is required.  This is especially true of the bottom end where you need really deep traps.

I'm treating a 10m2 room and I'll have 12, 1200mmx600mm panels inc a 300mm deep, floor to ceiling, bass trap and, on top of that, I'll be running room correction DSP on my monitors.  I already know that I'll still need to check the bottom end of my mixes using headphones.

Danny1969

The fact it's a loft space will help because A it isn't a square box and B the worse of the bass will go straight through the walls and ceiling as they aren't really rigid like a brick wall is. 

As @octatonic said work out what you need first. I did my old mic room by listening and then firing a sweep out out the monitors, recorded it back it and compared the 2 results. 

Every space that's not purpose built has problems, it doesn't have to be perfect for a hobby studio. Start with treating the corners and just put some diffusion above your head in the mix position. Then as long as you don't use too big a set of monitors or listen at loud volumes (your neighbours will hear if you do because the rooms got no mass ) you will be able to mix well enough... to the point the  the rooms won't be the weakest link. 

Dominic

Proper acoustic wall panel boards fitted with detachment buffers far more efficacy than Rockwool even if it is specialised soundproofing rockwool AR45