Caruso ISO Bond vs Rockwool

[producer12999]

Hi. I would like to treat my room soon. Originally, I wanted to put 17cm thick mineral wool monster absorbers from GIK Acoustics everywhere in my room. (I'm not talking about the corners + ceiling, I'm only concerned with walls etc for now).

My room is 20 square meters. Quantity goes before quality here. I am now wondering if it might not make more sense to use 40cm thick Caruso Iso Bond Panels (WLG045). The flow resistance of Caruso WLG045 is 3000 Pa.s/m2. (and its ultra low density, perfect for bass when thick enough)

Do you think it is the better decision?

I would build a lot of 40cm thick Caruso WLG045 panels and combine them with 30cm thick WLG040 panels. (these have a flow resistance of 5000 Pa.s/m2).

I generally wonder why rock wool is used everywhere worldwide in the largest studios. On paper, Caruso is 100x more suitable. And why are materials with comparatively high flow resistances, i.e. mineral wool, still used in large studios for bass handling? I don't know any mineral wool with 3000 Pa.s/m2)

What do you think? Could someone give me an explanation there?

(in the graph I compare 40cm Caruso vs. the 17cm Monster absorber from GIK. I have entered a rough value of 10000 Pa.s/m2 for rock wool, I do not know what exactly is used. Caruso becomes even more powerful when I increase the airgap. With the 17cm GIK panel, I can't go higher than 17cm airgap. In general, Caruso performs better on paper due to the flow resistance.)

Thanks!

 

[kemmler3D]

The better choice depends 100% on the existing acoustics in your room. Acoustic treatment is not a "more is more" product, nor is it one size fits all. I'll just be the first to ask this, since it happens in every thread:

Do you have a measurement mic (UMIK-1 is the usual recommendation) and have you taken measurements in the room?

If not, I would do that before you spend any bucks on thick treatments. A quick $100 and 2 hours spent on measurments can save you from spending $1000s on suboptimal solutions for your room.

Also, welcome to ASR! I think you've come to the right place with questions like this.

 

[producer12999]

The room will be ready for measuring next weekend. I will reply again here in the thread then. Thanks!

 

[producer12999]

The room will be ready for measuring from next weekend. I will reply again here in the thread then. Thanks!

The better choice depends 100% on the existing acoustics in your room. Acoustic treatment is not a "more is more" product, nor is it one size fits all. I'll just be the first to ask this, since it happens in every thread:

Do you have a measurement mic (UMIK-1 is the usual recommendation) and have you taken measurements in the room?

If not, I would do that before you spend any bucks on thick treatments. A quick $100 and 2 hours spent on measurments can save you from spending $1000s on suboptimal solutions for your room.

Also, welcome to ASR! I think you've come to the right place with questions like this.

But I don't really understand why you should prefer less thickness. The reverberation time is bad in any case, even if the frequency response is perhaps not so bad.

Of course measurements are important, I'll do some soon. But I'm running a home studio... just build fat traps and good is. After that, maybe work with diffusers. Or am I completely wrong?

The smaller the space, the more meaningless measurements are.

(room is treated 0% by now)

 

[ozzy9832001]

If you just build fat traps you are going to be severely disappointed unless you cover the entire room with them (waste of time and money). The low end, problematic frequencies are all pressure based. The type of absorbers your talking about are velocity. Where there is high pressure there is low or no velocity. So they are highly ineffective. Yes, ineffective doesn't necessarily mean useless.

In short, you'd end up with a very over damped mid/high end and a gigantic booming bass problem. Treating the correct problem with the right treatment is the key to success and if done correctly, you'd be surprised just how little treatment you really need.

While a lot of the tests in REW require a large, diffuse room to be 100% accurate, that doesn't mean the data is completely useless either.

 

[sam_adams]

I would build a lot of 40cm thick Caruso WLG045 panels and combine them with 30cm thick WLG040 panels.

You are intending to hang sixteen inch thick and twelve inch thick panels with a four inch airgap from the walls of your room? Do you intend to leave any space to move about in this room? Have you taken a moment to try and visualize what a twenty inch thick box will look like hanging from the wall? Treating any room to this extent will leave it extremely dead-sounding and audibly disappointing—unless, of course that is the intention.

Take a look at how mounting and placement of panel absorbers effects the RT60 measurements of the room—you don't need as much as you think you need.

 

[Scgorg]

I ended up going for Caruso's iso-bond panels at home. What is particularly great is that they have panels with relatively low flow resistivity, which allow thick panels that are effective at both high and low-mid frequencies. Making thick panels with high flow resistivity is not ideal for an even absorption spectrum. In my room I have 200+200mm WLG045/WLG040 on the back wall, which should yield high, even absorption down to about 100hz.

The room is quite small, so the speakers end up very close to the side walls, where I use 100+100mm WLG040/WLG035 panels. While I quite enjoy side reflections in larger rooms, I found it was helpful to attenuate them in mine. The front wall has 200mm WLG035 panels, which are honestly not that important with my current speakers as they are cardioid and don't radiate strongly towards the rear. I'm still considering treating the ceiling (perhaps instead of the front wall), but don't feel a strong need currently. My floor is also untreated (laminate on concrete). The measured improvements in steady-state frequency response post-treatment were small, as expected. Do not use frictional absorbers to improve in-room bass response. It's a fool's errand.

While RT is certainly not useful for small rooms at low frequencies (and of dubious value at higher frequencies), the RT60 of my room is a very stable 300ms. For some this is on the drier side, but I find that a comfortable range to aim for. Disclaimer: I was born with some hearing loss, and Toole has been quite clear that individuals with hearing loss may have a stronger preference for dry rooms and weaker early reflections than those of normal hearing. Take my comment for what it's worth, keeping that in mind.

I used this calculator to decide on what seemed like reasonable combinations/thicknesses of absorbers: http://www.acousticmodelling.com/multi.php
It allows you to input thickness, flow resisitivity, incidence angle, air gap, etc. It also includes references to the models used for the calculation (of which there are many). This is the calculator OP included a screenshot from in his first post.

 

[kemmler3D]

Realistically you will probably need membrane / resonant traps to deal with low frequency modes, instead of just adding more isobond. It looks like isbond will work okay down to 100hz, but you will need to think about facing it with something to avoid absorbing all of the mids and highs.

Treating a studio room with thicker and more panels doesn't necessarily get you where you want to go. The ideal for a studio is often said to be flat and dry, but what often happens is you end up dry AF everywhere above 200-400hz and honky/boxy AF below that. I've recorded in a vocal booth that was improperly treated like this, and it was hell dealing with the tracks that came out of it. There was treatment on all the walls but even for female vocals it was obvious the bass wasn't done correctly.

If you take measurements you can at least start to get an idea of how much isobond you will want to use, and if you measure as you go, you can stop adding wall treatments once the in-room response starts to tilt toward the low end, and change tactics at that point.

 

[Looneybomber]

I generally wonder why rock wool is used everywhere worldwide in the largest studios. On paper, Caruso is 100x more suitable. And why are materials with comparatively high flow resistances, i.e. mineral wool, still used in large studios for bass handling? I don't know any mineral wool with 3000 Pa.s/m2)

What do you think? Could someone give me an explanation there?

Here is one person’s take on it.

Caruso Iso Bond vs Rockwool - My reasons for a change

From the looks of things, Rockwool is a lot cheaper and easier/faster to get. That to me, says everything about why it’s so commonly used. Never underestimate cost and convenience when it comes to what motivates people.

Heck, the entire A/V industry is moving away from quality at the sake of convenience. Almost everything (video and music) is streamed with quality degrading compression. We’re living in a world where we want cheap and fast at the expense of quality.

 

[kemmler3D]

Almost everything (video and music) is streamed with quality degrading compression.

Well, music is increasingly streamed lossless (Spotify is said to be preparing to roll it out, FINALLY) but even UHD Blu-Ray uses video compression. Lossless 4K video has a truly unreasonable file size, for physical media or otherwise, even by today's standards.

There is a lot to be said for convenience. The most convenient way to get higher-quality video (physical media) was to send discs back and forth in the mail. These days if you want to upgrade video quality you can simply make a call to your ISP and upgrade your connection - if you live somewhere with a fast ISP, anyway.

 

[Scgorg]

I think it's worth noting that the rooms being spoken of here ("dry AF everywhere above 200-400hz") are typically those where a lot of rather band-limited treatment has been used. If you cover your entire room in 2-4 inch panels, that would be the end result generally. Treatment should be strategically placed, and when used, it should be broadband, which is why my thinnest panels are 8 inches. In my case it is not necessary to make these panels more reflective at high frequencies, as they are used sparingly (only about ~12% of my wall surface is treated, and that's not counting the floor and ceiling). Using a lot of treatment on a small surface > using a little treatment on a large surface.

Here is the in-room response of my Gradient Revolution, only 3 EQ points applied. 1 peak filter of -5dB to pull down a room resonance at 110Hz, 1 low-shelf of about 3dB@150Hz, and 1 peak filter of about -2dB@800hz where the speaker itself has a resonance. Note the 2dB divisions:

Listening distance is 2 meters. Dip at 200hz is boundary interference. Smoothing is 1/12 octave. Measurement method is MMM over a very small listening area. There's no less of high frequencies present here (the sharp drop above ~12-13kHz is the speaker itself, not the room). In fact the speaker is arguably quite bright, due to the flat-ish frequency response and almost constant directivity down into the bass (cardioid midrange and dipole woofers).

 

[producer12999]

If you just build fat traps you are going to be severely disappointed unless you cover the entire room with them (waste of time and money). The low end, problematic frequencies are all pressure based. The type of absorbers your talking about are velocity. Where there is high pressure there is low or no velocity. So they are highly ineffective. Yes, ineffective doesn't necessarily mean useless.

In short, you'd end up with a very over damped mid/high end and a gigantic booming bass problem. Treating the correct problem with the right treatment is the key to success and if done correctly, you'd be surprised just how little treatment you really need.

While a lot of the tests in REW require a large, diffuse room to be 100% accurate, that doesn't mean the data is completely useless either.

Yeah, I’ve heard about the pressure and velocity. According to your theory, however, it would mean that porous material has no effect on the bass when there is a lot of pressure.

What methods are there to minimize the pressure?
Active bass traps, Helmholtz and generally resonance absorbers?

 

[producer12999]

You are intending to hang sixteen inch thick and twelve inch thick panels with a four inch airgap from the walls of your room? Do you intend to leave any space to move about in this room? Have you taken a moment to try and visualize what a twenty inch thick box will look like hanging from the wall? Treating any room to this extent will leave it extremely dead-sounding and audibly disappointing—unless, of course that is the intention.

Take a look at how mounting and placement of panel absorbers effects the RT60 measurements of the room—you don't need as much as you think you need.

I always thought that once you build absorbers with a certain thickness, the room will not sound dead because the entire frequency spectrum can be absorbed.

A dead room means that the highs are gone, while basses are still full or not?

How can it be that in the largest studios meter thick mineral wool is inserted into the walls and the room does not sound dead. You want balanced dryness for mixing or am I wrong here?

And yes, of course I calculated the thickness of the modules for my room and sketches.

 

[DVDdoug]

A dead room means that the highs are gone, while basses are still full or not?

To me, a dead room means no reflections/reverb (at any frequency). But like a lot of audio terminology, it may mean different things to different people...

 

[fpitas]

A dead room means that the highs are gone, while basses are still full or not?

Sometimes. Unfortunately, amateur efforts often result in a room like that, which then gives the whole idea of room treatment a bad reputation.

 

[ozzy9832001]

I always thought that once you build absorbers with a certain thickness, the room will not sound dead because the entire frequency spectrum can be absorbed.

That's the problem though. The panels have different absorption rates for different frequencies. You want them to be relative to one another with as little variance as possible.

If you decay times were 250ms @ 1000hz, you'd want that at 60hz and 10000hz.

Without limiters or targeted treatments it will never be equal.

Dead really just means the room has a lot of absorption and extremely low decay times. Most people find it unnerving. The goal I always shoot for is about 250ms @ 60hz. Under 60hz I'm not too concerned with since almost all the music I listen to doesn't even reproduce much in that region.