Help! Positioning absorber and diffuser panels

[Beedster]

Folks

I have a decent booth for recording voice and instruments, but I'd like to get my mixing/editing room slightly better sorted. It's a 3m x 5m space. I've used foam tiles on the walls until recently which frankly were pretty good. I have however got an old set of MSR Acoustics Absorber, diffusor and cloud panels that I'd like to use as I'm confident they'll do a better job. I've used the absorbers recently and they'r e step up on the tiles. I have 5 absorbers, 5 diffusors and 2 clouds as per here http://www.msr-inc.com/studio/project/project_modules.html

This is the room layout suggested by the manufacturer for the tiles I have

The picture appears to suggest that I mount the absorbers and diffusors in pairs of one absorber and one diffusor each. My understanding of acoustics suggests that this is not the best way, but then I've consistently found throughout life that my understanding of many things is not necessarily the understanding shared by experts, so I thought I'd get some thoughts from you good folks.

Unlike the layout above I have a 2.5m, wide desk at at one of the narrow ends of my 3x5m room that faces into the room so that I can make eye contact with whoever is in the booth. If I was to do a lot of mixing I would almost certainly hang the the necessary number of panels c thereby creating a virtual wall between myself and the rest of the room.

One of the reasons I want good acoustics around the desk, apart from a decent listening environment, is that in voiceover work that I do I occasionally have to drop a few words or, more usually sentences in to the track during the edit, and to have to go back into the booth to do so is a PITA, so assuming there's no noise coming from the outside I prefer to do that at the editing desk. The problem at present however is that with the current setup there's a noticeable difference in ambience if I have to do more than a few words.

My main question however relates to the advisability or otherwise of the pairs of absorbers/diffusors.

Any advice/suggestions most welcome

Chris

Edited October 26, 2020 by Beedster

[lurksalot]

This is a very specialist area from what I can gather , to the point that I wouldn’t be surprised to see a ‘Harry Potter and the Auditory Minefield’ as the next chapter delving deeply into the dark arts involved, followed in the series by ‘Harry Potter and the Plasterer’s Apprentice’

in seriousness I think you can get a software / microphone package that can assess your room , and you can play with the set up and actually measure it so you can pick the best layout , but I would guess a good start would be the manufactures suggestions.

@Skol303 is the guru on this, he can point you in the right direction with his sonic wand 

 

[Beedster]

10 hours ago, lurksalot said:

This is a very specialist area from what I can gather , to the point that I wouldn’t be surprised to see a ‘Harry Potter and the Auditory Minefield’ as the next chapter delving deeply into the dark arts involved, followed in the series by ‘Harry Potter and the Plasterer’s Apprentice’

in seriousness I think you can get a software / microphone package that can assess your room , and you can play with the set up and actually measure it so you can pick the best layout , but I would guess a good start would be the manufactures suggestions.

@Skol303 is the guru on this, he can point you in the right direction with his sonic wand 

 

Thanks mate, I think like most aspects of gear there are opinions, general principles and experience, the latter is what I’m after, there’s plenty of the former two on the web already. As with all such things it’s going to need a trial and error approach to a degree, but it would be good to minimise the error as much as possible early on  

[lurksalot]

56 minutes ago, Beedster said:

Thanks mate, I think like most aspects of gear there are opinions, general principles and experience, the latter is what I’m after, there’s plenty of the former two on the web already. As with all such things it’s going to need a trial and error approach to a degree, but it would be good to minimise the error as much as possible early on  

Experience of this is not my field Chris, but I would imagine that minimising the error would depend on the amount of treatment the room needs, that is probably the experience of the panel people working on the room size and shape told to them. Once you start to play around with listening and performance areas within that , I would have thought while the theory would remain the same, the application of it would be like plaiting fog.

have fun and good luck 

[Beedster]

4 minutes ago, lurksalot said:

Experience of this is not my field Chris, but I would imagine that minimising the error would depend on the amount of treatment the room needs, that is probably the experience of the panel people working on the room size and shape told to them. Once you start to play around with listening and performance areas within that , I would have thought while the theory would remain the same, the application of it would be like plaiting fog.

have fun and good luck 

Agreed, plaiting fog indeed

The best test for me at present is simply comparing a voice track recorded in the booth to that recorded at the desk using the same mic and placement. The ambience in the editing space is quite noticeable, despite the fact that acoustically the absorber panels I've installed already dampen the room considerably to the naked ear.  

[Beedster]

Anyone got any ideas about diffusers and absorbers positioned adjacent to each other? It's odd because the manual for the units themselves appears pretty clear on it but I can't find anything on, for example, Gearslutz or similar about it. So, I'm going to assume that, as common sense suggests, it's probably not standard practice. Would like to have the thoughts of anyone who's done it however. 

[BigRedX]

I'd ask this question over at the Sound on Sound forums.

[Beedster]

13 minutes ago, BigRedX said:

I'd ask this question over at the Sound on Sound forums.

Thanks mate, I know there's a few folks on here who i can trust, venturing onto a new forum I suspect I'll get a load of noise. I'm going to run a few trials, bit I'm pretty confident that the above picture is more a case of the manufacturer wanting to sell what they want to sell as opposed to offering reliable advice. I assumed that because they'd placed pairs of absorbers/diffusers at reflection points for the monitors, that there might be something significant that I was missing - who knows, even a new magic bullet for acoustic treatment - but my gut feel is that in a room the size of that in the diagram you wouldn't put the diffusers where they've put them.

[Beedster]

1 hour ago, BigRedX said:

I'd ask this question over at the Sound on Sound forums.

I've asked there also, thanks for the suggestion BRX. I anticipate being able to understand about 10% of the response(s) 

[BigRedX]

29 minutes ago, Beedster said:

I've asked there also, thanks for the suggestion BRX. I anticipate being able to understand about 10% of the response(s) 

You'll pick up the jargon pretty quickly. Take particular note of anything Studio Support Gnome posts. He does (or used to do) this stuff for a living.

[TwoTimesBass]

Engineers historically would have you believe there is a magical voodoo art to acoustics when really it's pretty simple unless you're dealing with huge or odd-shaped spaces. The Sound on Sound books/articles on studio acoustics are really well researched and explained IMHO and a great resource. You seem to have a decent handle on what you're trying to achieve and how to go about it. Most rooms typically need a mixture of diffusion and absorption, killing any flutter echoes while flattening the frequency response. Hence the fairly generic diagram from MSR dealing with sidewall and ceiling reflections then some general dampening.

I've done a similar thing (with similar problems) double tracking harmony parts. I've done the base parts standing at the mic properly, but for the double/tripe-tracks it's quicker to sit in front of the computer and do them. Biggest thing that was upsetting the sound in my studio was the wall of 2x monitor speakers and dual screens in a semi-circle behind the mic!

Another thought, what are the dimensions of your booth? It could be that actually the booth has an acoustic that can't be replicated by you sitting in a more open room. I've found this particularly in smaller vox booths, usually manifesting itself in the low-mids freqs of vocal recordings.

 

[Beedster]

Hey TwoTimesBass

Many thanks, that's really helpful. Firstly the booth is very dead and I like that for voiceover but as you suggest, it presents problems trying to mimic that ambience outside of the room. I use an SE reflection screen around the mic at my desk, and because I'm facing into the room I have absorber panels directly behind me, so I'm less affected by screen than might otherwise be the case. It's a wooden cabin so I've just installed some cloud absorbers above my desk also, and I'm going to test this today (I have some bass traps coming from EQ Acoustics which I suspect are going to also help a lot, I think I've been a little bit naive in assuming that in recording the human voice dealing with bass frequencies in the room isn't really an issue).   

I think you've answered my main question, which is that the balance of absorbers and diffusers is probably important, and I'm therefore going to do some trial and error. Whilst it sounds odd, and also flies in the face of most of the thinking on this, I'm going to try a diffuser in the booth also (it's 1.8 x 1.8 m so actually quite big, whilst I had it built for voiceover work, I was also keeping a keen eye on recording double bass, acoustic guitar and fiddle in there, and it's amazing how much space you actually need to play those properly). 

I'll post my findings when I have some findings

[Pea Turgh]

Hello.  Assuming the booth is all absorption, you won’t be able to easily match the ambience to your larger space.  The human ear is just too sensitive to the differences.

If you put some diffusers in the booth, you will be able to hear the size of the room, and I don’t think you’ll like it.

With regards to positioning, I’d be inclined to leave the diffusers out completely for now - get a feel for the room with just absorption in the main places (pretty much as per the manufacturer plan).  Add the diffusers back in if you feel the room is too dead (which it would be unlikely to be unless it was close to total absorption coverage).

Just try amateur opinion 😁

[TwoTimesBass]

13 hours ago, Beedster said:

I use an SE reflection screen around the mic at my desk

Darn it, that was going to be my killer solution for you 😀

Pea Turgh makes a good point in that it's hard to make a larger room sound like a small booth and vice versa. Given that you've already got the SE screen, some portable free-standing acoustic panels that you can use to wall yourself in with might be an option when recording at the desk. Cheaper than treating the whole room and can be deployed elsewhere or stacked away depending on the circumstances.

13 hours ago, Beedster said:

I think I've been a little bit naive in assuming that in recording the human voice dealing with bass frequencies in the room isn't really an issue).

Yes very true, I used to do a lot of solo voiceover and audio-description recording and it's interesting when the HPF is having an effect at 150-200Hz on female voice! Editing spoken word with a sub in the monitoring setup was one of the best tips I ever was given, all the plosives, pops and bangs you can miss...

13 hours ago, Beedster said:

whilst I had it built for voiceover work, I was also keeping a keen eye on recording double bass, acoustic guitar and fiddle in there, and it's amazing how much space you actually need to play those properly). 

I have a roughly 3' x 4' vocal booth in the studio at work which we never use, it's basically a cupboard for my instrument collection as it always sounded too boxy regardless of the acoustic treatment. We do all the recording in the control room as acoustic instruments really do benefit from a bit of space to breathe, especially the lower down the frequency range you go. For Double Bass you really want to put the mic at least a meter away.

Good luck with your experiments, you'll find something that works for your room and sounds good to your ears, which is ultimately what counts. Have fun in the process!

 

[Beedster]

11 hours ago, Pea Turgh said:

Hello.  Assuming the booth is all absorption, you won’t be able to easily match the ambience to your larger space.  The human ear is just too sensitive to the differences.

If you put some diffusers in the booth, you will be able to hear the size of the room, and I don’t think you’ll like it.

With regards to positioning, I’d be inclined to leave the diffusers out completely for now - get a feel for the room with just absorption in the main places (pretty much as per the manufacturer plan).  Add the diffusers back in if you feel the room is too dead (which it would be unlikely to be unless it was close to total absorption coverage).

Just try amateur opinion 😁

Many thanks, yes from what I've read diffusers are either going to make things slightly better or a whole lot worse (especially in the small room as you suggest). Luckily the mounting system for the absorbers and diffusers is the same so I'm able to experiment with little hassle. 

I love your point about the human ear and differences, as I keep trying to explain to my colleagues, many of the differences in question are not overt/conscious, the recording just doesn't feel as good. I want everything I record to feel good

[Beedster]

9 hours ago, TwoTimesBass said:

Darn it, that was going to be my killer solution for you 😀

Pea Turgh makes a good point in that it's hard to make a larger room sound like a small booth and vice versa. Given that you've already got the SE screen, some portable free-standing acoustic panels that you can use to wall yourself in with might be an option when recording at the desk. Cheaper than treating the whole room and can be deployed elsewhere or stacked away depending on the circumstances.

Yes very true, I used to do a lot of solo voiceover and audio-description recording and it's interesting when the HPF is having an effect at 150-200Hz on female voice! Editing spoken word with a sub in the monitoring setup was one of the best tips I ever was given, all the plosives, pops and bangs you can miss...

I have a roughly 3' x 4' vocal booth in the studio at work which we never use, it's basically a cupboard for my instrument collection as it always sounded too boxy regardless of the acoustic treatment. We do all the recording in the control room as acoustic instruments really do benefit from a bit of space to breathe, especially the lower down the frequency range you go. For Double Bass you really want to put the mic at least a meter away.

Good luck with your experiments, you'll find something that works for your room and sounds good to your ears, which is ultimately what counts. Have fun in the process!

 

Many thanks again, I agree with all of the above, the mobile panels especially. Re vocal booth, the main reason I have mine is not for the internal ambience but to exclude noise, my studio is in a suburban garden and suffers form all of the issues - power tools, dogs, kids, aircraft - you'd expect. I need to know that when I plan a day of recording that I'm not at the mercy of my neighbours! If the room was soundproof I would do all the voiceover work at my desk.

And yes, I'm going to start listening to voiceover using my sub also. I was really suprised to learn just how low the fundamental of the human voice is