Acoustic treatment in home studio - Let the fun begin

ChrisRG

So, after an age of detailed research (my wife calls it procrastination!) I've finally got the materials together to put some acoustic treatment into my home studio.

I'm planning to build some panels so I thought I'd detail the work here in case anyone was thinking of doing something similar or could offer any thoughts/advice.

I'll put some photos etc up at the weekend but the basic detail are as follows

Studio - 3m x 4m 
Treatment - Rockwool RW3 100m slab which will be built into frames and covered in Cara fabric.

I've got an omnidirectional mic which I did some tests with ages ago so I'll redo those before and after.

I pick up the wood on Saturday and have everything else so there's no excuses now!!

I know there are problems in the room especially at the low end some I'm trying to reduce some of the bass, control the mids/highs a bit and stop 1st reflections.

Musicwolf

At 3m x 4m your room is a gnat’s whisker bigger than mine.  Bass is going to be your biggest issue.

Do you have a floor plan that you can share?  Best layout is nearly always to have the speakers firing down the long side.  There’s some theory floating about to suggest that the best listening position will be 38% of the room’s length back from the front wall so, in your case, that’s 4m x 0.38 = 1,52m back.  I usually work sitting forward of the point but I have a reference point so that I can push my chair back for critical listening.  Monitors should be set up to form a equilateral triangle with the point at this position (tweeters at head hight).

Absorbers.  I have 100mm thick 1200mm x 600mm panels at the first reflection points (walls and ceiling) spaced 100mm from the wall to extend the frequency range.  What you are trying to do with a broadband absorber is to take the Kinetic Energy of the moving air and turn it into minute amounts of heat.  When you have a standing wave the air isn’t actually moving at the wall, the max KE is at the ¼ wavelength and this is where your absorber is most effective.  200mm from the wall equates to about 400Hz.  It will work below this frequency but not so effectively.

The best place to control the bass is in the corners.  I have ‘super chunks’ in my front corners (triangles of RW3 stacked to the ceiling), mine don’t go floor to ceiling as they are sitting on my worktop but floor to ceiling is best and all 4 corners if the room allows.

I’m thinking of re-doing my entire room which will involve taking out the worktop, installing a custom built desk and rebuilding the corners.  I’m thinking of having a limp mass membrane in front of the chunks (mineral loaded vinyl) and further 100mm rockwool slabs in front of the membrane.  There’s a good article in last month’s Sound on Sound.  I’ve been thinking about doing this since I first read about the technique more than 10 years ago – so I can’t be accused of rushing into doing it.

Musicwolf

Here are a couple of aticles re the limp mass traps

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

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

I can't believe that the earlier one was 2006, time to pull my finger out.

Stuckfast

Don't forget that there are corners between the ceiling and walls also. Those are often a good way to get treatment in place without losing space in the room.

Musicwolf

Yes, good point.  If you want to test things it's also worth remembering that sound doesn't know up from down so you can lay your absorbers across the floor / wall intersections during tests to get an idea as to how they will work.

The corners of the room where three surfaces come together are the best places to aim for.

ChrisRG

Thanks a lot for the info @Musicwolf and @Stuckfast ;

I’ll get a plan up in the next few days after I’ve thrown it together on SketchUp. I did have one but can’t seem to find it. 

I’ve got my desk in the middle of one of the short walls so the sound is going lengthwise. I understand completely about bass trap in corners and at the moment I have 3 corners taken up with a bookcase, Marshall fridge and the door. 

I thought about a 3 phase approach. Firstly 4 panels, 1 either side of the listening position and 2 on the back wall. Next, listen and measure and see where we’re at.  These panels would be identical to the ones @Musicwolf describes. They wouldn’t be 100mm from the wall though. I understand the difference it makes but I’m concerned about the physical impact on the room. 
Phase 2 was to be RW3 super chunks.  I’ve already got  idea for those (and enough RW3) and I’d move/ditch the cupboard and fridge or do the back and block the door temporarily. 

Phase 3 could be cloud panels and ceiling/wall traps if needed. 

I’m trying to get a balance of treating the room enough to improve the sound and preserving some space in the room if that makes sense. 

Musicwolf

ChrisRG said:

I’m trying to get a balance of treating the room enough to improve the sound and preserving some space in the room if that makes sense. 

I know exactly what you mean.

My room is a converted garage.  When I first had it turned into a room I had floor to ceiling traps in the back corners as well as the front but they were taking up too much space (in recent years the room has had to double as a home office).   I'm now weighing up the benefits of improving the acoustics vs losing the convenience of the office / storage.

ChrisRG

Mine’s a home office too as well as a drum room for my 8 yr old so I can’t go too mad. 

I’m also not doing anything commercial with the music or space so it doesn’t need to be perfect, just better. 

Bill_S

Chris, all that you have planned will make a huge positive impact. I took advice and bought my panels from GIK Acoustics, because aesthetics were really important to me and my DIY skills are limited. As well as the usual panels on the side and back walls, I have two panels hanging above the speakers and my listening position to stop reflections from the ceiling in a room slightly smaller than yours. 

Because of a door and a small entrance way to the room, I could not do enough about the low end, which means I tend to hear less bass in the mix than there really is. I now automatically compensate for this by reducing the lower end when I’m mixing - not foolproof or ideal but I’m used to it. That said, there is so much I can hear with brilliant clarity now - the full treatment was done three years ago and it is one of the best investments in music I have ever made. 

Will be really interested to hear how things go for you. 

ChrisRG

So, the work started today.  Here's a sketchup of the studio
and this one shows the door and windows in really annoying places

ChrisRG

I'm planning to put 2 panels on the rear wall and 1 either side of the listening position.  Those windows have window boards that stick out about 35mm so I'll need to think about how I mount on the right,

octatonic

Pull your speakers and desk off the wall.
Ideally you want the listening position around 38% of the length of the room.

ChrisRG

So, anyway.  I built the first panel today.  It took hours but I was triple checking everything as I went along.

The frame


The RW3 in the frame


And the finished panel


It came out really well I think.

ChrisRG

octatonic said:

Pull your speakers and desk off the wall.
Ideally you want the listening position around 38% of the length of the room.

In reality, the desk is about 150mm from the wall but yes, ideally it should be further out.

octatonic

Ideally you want your seat about 1.5m into the room from the wall, if your room length is 4m.
Put your desk in the right place to suit that and form an equilateral triangle between your ears and the speakers- this might require speaker stands.

This gives you an idea of how to set things up:
My speakers are a compromise, the Kii Audio monitors are closer to the perfect spacing than the ATC'a.

Kebabkid

Great job.

I wish I was capable of this as I ended up getting ceiling to floor bass traps from Blue Frog Audio. I'm pleased and they make a big difference. Have they done the job?

Rich210

Quality mate, I've had grand ideas for doing DIY sound solutions on the really cheap but I think this is the way forward for sure. 

ChrisRG

Thanks @octatonic   I’ll give that layout a go. I have a pair of presonus eris 3.5s so nothing high end but I’m sure it’ll make a difference.  The room is a compromise though due to it being a home office and containing a junior drum kit.  

ChrisRG

Kebabkid said:

Great job.

I wish I was capable of this as I ended up getting ceiling to floor bass traps from Blue Frog Audio. I'm pleased and they make a big difference. Have they done the job?

My skills are nothing special. The hardest bit was getting 100mm wide timber as it’s not a standard finished size. The other tricky bit was getting the RW3 in lockdown. It’s not available in normal DIY shops and a lot of suppliers ship by the pallet. 

Still need to build another 3 panels and mount them before I know if they work. 

ChrisRG

Rich210 said:

Quality mate, I've had grand ideas for doing DIY sound solutions on the really cheap but I think this is the way forward for sure. 

I reckon it’ll come out at about £45 - £50 a panel.  

It’s not cheap but I went good quality fabric and had the wood planed down to size. You could definitely cut the cost down by using a different fabric and cutting down sheets of MDF to make the frame. 

Musicwolf

The Cara fabric is well worth the money as, acoustic properties aside, it enables a good cosmetic finish (plus it's fire retardant).  The first traps that I built used simple cotton fabric, but I learned from that mistake.