Gearslutz

Gearslutz (https://www.gearslutz.com/board/)
-   Studio Building / Acoustics (https://www.gearslutz.com/board/studio-building-acoustics/)
-   -   AFMG Soundflow - Settings? (https://www.gearslutz.com/board/studio-building-acoustics/1171465-afmg-soundflow-settings.html)

Jack Napier 28th August 2017 09:36 PM

AFMG Soundflow - Settings?
 
Hey,

what settings in Soundflow give the most realistic result when comparing to measurements?

Dimension: Infinite or Iso or User?

Thanks

Jens Eklund 28th August 2017 09:52 PM

That would naturally depend on what kind of measurement you're comparing. Reverberation chamber or impedance tube. If Chamber: use the same size as the sample used in the actual measurement. If impedance tube; use infinite. Also, you naturally need to use diffuse (random incidence) setting for reverberation measurements and 0 deg incidence for tube.

Jack Napier 28th August 2017 10:05 PM

Quote:

Originally Posted by Jens Eklund (Post 12817345)
That would naturally depend on what kind of measurement you're comparing. Reverberation chamber or impedance tube. If Chamber: use the same size as the sample used in the actual measurement. If impedance tube; use infinite. Also, you naturally need to use diffuse (random incidence) setting for reverberation measurements and 0 deg incidence for tube.

Sorry,

i mean not comparing to data.

what do you use if you compare it to actual room measurements?

or what do you use when guys ask you how good their trap will be working?

Jens Eklund 28th August 2017 10:12 PM

Quote:

Originally Posted by Jack Napier (Post 12817365)
Sorry,

i mean not comparing to data.

what do you use if you compare it to actual room measurements?

or what do you use when guys ask you how good their trap will be working?

So reverberation chamber then, or do you mean a sample of a certain size in a large room and using gated impulses to evaluate an absorbers performance?

Jens Eklund 28th August 2017 10:14 PM

Or possibly a whole wall covered in an otherwise empty room with solid walls, and assuming plane wave behaviour if very low frequency; then it will behave similar to an impedance tube.

Jack Napier 28th August 2017 10:27 PM

Quote:

Originally Posted by Jens Eklund (Post 12817381)
So reverberation chamber then, or do you mean a sample of a certain size in a large room and using gated impulses to evaluate an absorbers performance?

i just want to get an idea what combining different layers will do in reality.

you say diffuse field (for incidence)
and the iso 345??

Jack Napier 28th August 2017 10:49 PM

Quote:

Originally Posted by Jens Eklund (Post 12817385)
Or possibly a whole wall covered in an otherwise empty room with solid walls, and assuming plane wave behaviour if very low frequency; then it will behave similar to an impedance tube.

Example:

First Reflection area side walls

120 cm wide

250 cm high

angle of incidence is usually around 0 - 30 degree for first order refelections



which settings would you use to calculate the absorber?

Jens Eklund 29th August 2017 06:51 AM

If small room acoustics and/or first order reflections is considered; use the specific angle of incidence and infinite area.

green eyed girl 29th August 2017 10:00 AM

Quote:

Originally Posted by Jens Eklund (Post 12817933)
If small room acoustics and/or first order reflections is considered; use the specific angle of incidence and infinite area.

Where to get this software?

Jack Napier 29th August 2017 10:10 AM

Quote:

Originally Posted by Jens Eklund (Post 12817933)
If small room acoustics and/or first order reflections is considered; use the specific angle of incidence and infinite area.

I finally read the manual. I was just to lazy to do this. This looks ok.

It would be wrong to assume a diffuse field in small rooms, just makes the graph look better - but is simply wrong. Anyway.


I only try the software to see if it does something for me.
Are there similar programs for calculating treatment depth that are worth to look at? (apart from the online calculator)

Jack Napier 29th August 2017 10:11 AM

Quote:

Originally Posted by green eyed girl (Post 12818096)
Where to get this software?

Downloads - AFMG SoundFlow

Try before you buy

Jens Eklund 29th August 2017 10:24 AM

Quote:

Originally Posted by Jack Napier (Post 12818106)
Are there similar programs for calculating treatment depth that are worth to look at? (apart from the online calculator)

SoundFlow is the best I’ve found so far, but to be honest; I haven’t looked around much last few years (haven’t had the need).

Jack Napier 29th August 2017 10:53 AM

Quote:

Originally Posted by Jens Eklund (Post 12818117)
SoundFlow is the best I’ve found so far, but to be honest; I haven’t looked around much last few years (haven’t had the need).

i haven´t used anything till now. but since rooms are getting always smaller today i have to change my strategy sometimes.

people don´t always have space for 300 mm and up thick treatment.

so i have to experiment with different layers of more ridgid stuff if a just small space is available.

but there are countless types of rockwool available. and in different areas they are different priced. and they all differ in specs. so i am searching for a tool that can predict the performance of the material i have to use.

DanDan 29th August 2017 03:12 PM

Holy Grail
 
Demetris here on GS offers a free calculator, predictor. It is fun, educational, and a bit of a reality check in terms of expectations.
But the behaviour of waves in a small room is extremely complex so any choice such as random or a single degree of incidence cannot deliver a realistic assessment. Also corner behaviour, which is mighty, is not factored in.
Lastly perhaps, the damped membrane effect of semi rigid fibre is not factored in.
So that calculator does well at encouraging the use of very thick light fibre, but doesn't recognise the usefulness of thin semi rigid traps straddling corners and so on. I am not sure that any calculator does or even could as the effects are quite complex. I mean how does one assess rigidity or frequency of resonance of a batt of 100KG fibre? Which afaik also varies a lot from sample to sample.

So overall, rather than looking to prediction, I suggest looking to tests and empirical evidence. The manufacturers of typical 100mm traps and larger have plenty of advertising showing good results. Many rooms are shown here before and after. The BBC R&D have come up with various LF solutions, including whole wall partitions of sheet steel, damped obviously. RPG and Renz manufacture 100mm thick traps, again involving steel, which are very effective around 70Hz.
There are softer membrane devices by RPG, Primacoustic, and afaik GIK.
PSI do an active powered trap.

DD

Jack Napier 29th August 2017 07:15 PM

Quote:

Originally Posted by DanDan (Post 12818422)
Demetris here on GS offers a free calculator, predictor. It is fun, educational, and a bit of a reality check in terms of expectations.
But the behaviour of waves in a small room is extremely complex so any choice such as random or a single degree of incidence cannot deliver a realistic assessment. Also corner behaviour, which is mighty, is not factored in.
Lastly perhaps, the damped membrane effect of semi rigid fibre is not factored in.
So that calculator does well at encouraging the use of very thick light fibre, but doesn't recognise the usefulness of thin semi rigid traps straddling corners and so on. I am not sure that any calculator does or even could as the effects are quite complex. I mean how does one assess rigidity or frequency of resonance of a batt of 100KG fibre? Which afaik also varies a lot from sample to sample.

So overall, rather than looking to prediction, I suggest looking to tests and empirical evidence. The manufacturers of typical 100mm traps and larger have plenty of advertising showing good results. Many rooms are shown here before and after. The BBC R&D have come up with various LF solutions, including whole wall partitions of sheet steel, damped obviously. RPG and Renz manufacture 100mm thick traps, again involving steel, which are very effective around 70Hz.
There are softer membrane devices by RPG, Primacoustic, and afaik GIK.
PSI do an active powered trap.

DD

i am not a fan of panels - i am sure they have their place...

i like to treat full surfaces - it makes the job easier and looks better in the end.

DanDan 30th August 2017 02:48 PM

Area
 
That is bound to work better in terms of decay and modes. But I would note that the BBC stated that collections of their modular units distributed over the boundaries, created 'a diffuse sound field'.
For your purposes, I think Demetric Calculator will work perfectly well as you are not dealing with the exceptions. Acoustic Modelling - Home Page
DD

Deleted 56021e5 19th September 2020 05:59 PM

Insul is better than Soudflow but it costs twice the price


Quote:

Originally Posted by Jens Eklund (Post 12818117)
SoundFlow is the best I’ve found so far, but to be honest; I haven’t looked around much last few years (haven’t had the need).


Deleted 56021e5 19th September 2020 06:03 PM

To compare to actual room measurements you cannot use Soundflow.

You either use a ray tracing hybrid like CATT or ODEON... but for small rooms only works 500 Hz up.

For soundproofing you can use ACOUBAT or something similar but only valid from 125 Hz up

Studio construction is a very tiny market in acoustics. Most of this software is done thinking in building acoustics projects (residential buildings, offices, schools) or large room acoustics (concert halls, churches)

Even Soundflow has several limitations at low frequency


Quote:

Originally Posted by Jack Napier (Post 12817365)
Sorry,

i mean not comparing to data.

what do you use if you compare it to actual room measurements?

or what do you use when guys ask you how good their trap will be working?