New Studio - New Zealand

Hi All, First of all I want to say thanks to all those involved in making this site such a great resource! Has been very educational for me over a number of years. I’m now in a position where I have a new room that I want to use as a single room studio - serving both as control room and a live room and would be keen to get advice on the best way forward. Attached are 2 sketchup files – one shows the current arrangement, the other shows the kind of thing I’m considering doing. Also attached are a bunch of photos of the existing space and acoustic treatment I have at present (described below). The space: • It’s a room on the north-west corner of an old wooden house in New Zealand (north is up in the image). • Overall length of the room is 5.0m including a lean-to at the north end of the room. • At its widest point the room is about 4.25m wide. A closed-in fireplace intrudes into this space and also the lean-to portion of the room is only 3.0m wide. • Ceiling height in the main area is 3.1m. In the lean-to it’s about 2.5m. • There are a number of windows / doors as indicated by openings in the sketchup file. In particular, there is a large ranch slider arrangement on the west side of the room that I currently have covered with a bunch of acoustic panels – for privacy from the street as much as for acoustic reasons. • Floor is timber construction and is carpeted. Walls are timber framed and lined in some form of hardboard (not plasterboard). I’m not sure if there is any insulation in the walls. Ceiling to the lean-to is the same as the walls but the main ceiling is original finished timber and I’d like to keep this exposed if possible. There is insulation in the ceiling. • I understand that the preference is generally to have a wooden floor and absorptive ceiling, but would prefer not to do this at this stage. • The room doubles as my office (I work from home – not on music unfortunately!) Proposal • The second sketchup file shows what I’m thinking of for a general arrangement. I haven’t called up what is what in terms of the acoustic treatment I’ve indicated. This is the main thing I’d like assistance with defining – what should be bass traps, what should be slot resonators, what should be high frequency absorption, how I should go about constructing these. • Ultimately I would love to sound proof the space, but at this stage I’m only really looking at acoustically treating the room to get it as neutral as possible. The neighbourhood is reasonably quiet so not too much noise coming in, and the loudest sound I’ll be recording is probably acoustic guitar & voice – drums are electronic and electric guitars & bass I’m mainly going to DI. • I need to try and achieve a balance between the ideal acoustics for a control room and a live room but would prefer to err on the control room side so I can create translatable mixes. I’m prepared to use reverb plug-ins if I need to compensate for a slightly dead live space. • Budget – let’s say NZ$3,000, but I could consider spending more if that budget just won’t achieve what I’m wanting • I’m looking at removing the chimney and therefore will probably need to re-line the eastern wall. Might make sense to frame up a new wall in this location with a separation from the existing framing to give some isolation (there is a living room on the east side of it). • I’m looking at putting a new ‘temporary’ internal wall to cover up the ranch slider on the western wall. • I could look at angling these new walls, but would prefer to keep them square and provide angled surfaces by way of slot resonators, etc, that can be removed at some future point in time. The main reason for this is to make it so the room could be easily converted back to a ‘normal’ room in the future. I don’t mind constructing angled walls if these could be taken down without too much trouble at some point in the future though. • My monitors are Mackie HR824s. I currently have these sitting on my desk but would prefer to move them a bit further away (and wider apart). I understand these shouldn’t be soffit mounted, so am looking at building some stands out of 100mm di. PVC pipe filled with sand. • My monitors and desk are currently positioned to aim for a focal point of the 37% of the room length from the north end. • The window on the north is the only window I really want to keep clear, to maintain a view into the garden. However, as this isn’t an opening window so I’d be keen to keep either the small window on the west of the lean-to openable, or perhaps the window at the north end of the ranch slider. In the second sketchup file I’ve put holes in the acoustic treatment in what would be the ideal locations. Hopefully that would be workable. I have an HRV system installed in the house and could possible look at reconfiguring this to provide ventilation into the room if necessary, but would also like to have the option of at least one opening window. Resources: • I have some acoustic panels I made a few years ago from 100mm thick Siliner that I’d like to re-use. Siliner is a rigid fibreglass for lining air conditioning ducts that I think is similar to Owens Corning 705, etc. Here’s a link: http://www.forman.co.nz/products/Thermal_Insulation/Pipe_and_Air_Conditioning_Insulation/Ductliner_Unfaced_Siliner_Mat_Faced_Ductiner_Perforated_Foil_Faced • I have 4 panels 1.24m square and 8 panels measuring 1.24 x 0.64m. These are framed in timber and covered in cloth. • I have about 8 commercial plaster ceiling tiles measuring 600mm sq that I think might be able to be used as slot resonators if placed in front of some fibreglass. Refer photo. So that hopefully covers everything – If I’ve missed any important details let me know and I’ll try and fill in the gaps... Any advice much appreciated!

Hi "somalade", and Welcome! :) You have an "interesting" shaped space there. But it does seem to be big enough that you should be able to get it sounding nice.

• Floor is timber construction and is carpeted.

You say that you don't want to change that, but you should be aware that the carpet is probably a large part of the problem with your room acoustics. Carpet is selectively absorbent, in a random and unknown way. But worse than that, it does exactly the opposite of what you need for a small room. Carpet absorbs high frequencies very well, mids to a certain extent, and lows not at all. But you need the reverse: You need to absorb huge amounts of low frequencies, quite a bit of mids, and no highs. So the carpet is fighting your efforts, and reversing the effect of other treatment. You will therefore need to treat the room a whole lot more if you insist on keeping your carpet, and some of that treatment might be rather unusual, as it will have to counteract what the carpet is doing.

I need to try and achieve a balance between the ideal acoustics for a control room and a live room but would prefer to err on the control room side so I can create translatable mixes.

Have you considered make the acoustics variable? There are several things you could do to make it possible to change the room from a more neutral environment for critical listening / mixing / mastering, to a more live or even dead sound for tracking.

• My monitors are Mackie HR824s. I currently have these sitting on my desk but would prefer to move them a bit further away (and wider apart). I understand these shouldn’t be soffit mounted, so am looking at building some stands out of 100mm di. PVC pipe filled with sand.

Definitely! That was one thing I noticed in the photo that needs fixing. Those are fairly big monitors, and it definitely looks like you have your head too close to them. Even though "near field" and "far field" are much more marketing hype than real definable technical terms, there still is the issue that you need a certain amount of distance between the speaker and your head for the sound emitted by the tweeter and the sound emitted by the woofer to merge into a more or less even sound field. To me, it looks like your head is not far enough away for that to be the case. I tried to find a recommendation from Mackie for that, but came up empty. But you'd probably need at least 5 or 6 feet between your ears and the speakers. So massively heavy stands right up against the front wall seems like the way to go.

• I have about 8 commercial plaster ceiling tiles measuring 600mm sq that I think might be able to be used as slot resonators if placed in front of some fibreglass. Refer photo.

I don't see how those would act as slot resonators. Maybe some type of unusual diffuser, but there doesn't seem to be any reason why those would work as Helmholtz resonators. Even if they did, what frequency would they be tuned to, and would that be a frequency that you need to treat? I didn't see any actual questions in your post, so I'm just offering general impressions on some of what you said. I hope that's useful! - Stuart -

Hi Stuart Thanks heaps for your thoughts & suggestions...

Soundman2020 wrote:

So the carpet is fighting your efforts

OK, I think you have me convinced that it would be worth it removing the carpet.... part of the reason for keeping it was so allow me to keep the ceiling as is without adding absorption. But as you note, that theory doesn't really fly anyway. And thinking about it, the way the ceiling is constructed would make it relatively straightforward to add some absorption between the existing beams if required.

Have you considered make the acoustics variable?

Indeed - that would be the best way to tackle it. Will look into options. But please let me know if you have any specific examples in mind.

But you'd probably need at least 5 or 6 feet between your ears and the speakers. So massively heavy stands right up against the front wall seems like the way to go.

Yep that's what I'm thinking...

I dont see how those would act as slot resonators.

What I probably didn't make clear is that the tiles have slotted holes in them measuring about 47mm x 7mm (the darkest parts in the photos). The surface of the tiles is made up of alternating raised strips (12mm wide) and grooves (7mm wide). 50% of the groove part is solid, the remainder are holes. Overall thickness of the tiles is 16mm in the raised strips and 9mm in the grooves. Not sure if that makes a difference? As you note though may not be easy to calculate how to tune them - I guess I could try and measure their effects though.

I didn't see any actual questions in your post, so I'm just offering general impressions on some of what you said. I hope that's useful!

My main question was a bit buried in the post...

This is the main thing I’d like assistance with defining – what should be bass traps, what should be slot resonators, what should be high frequency absorption, how I should go about constructing these.

So, basically wanting advice on where to start with planning the acoustic treatment (assuming the fundamental concept is OK)... Am thinking I should buy some rigid fibre glass, make some corner bass traps, measure the impact and go from there?

OK, I think you have me convinced that it would be worth it removing the carpet.... part of the reason for keeping it was so allow me to keep the ceiling as is without adding absorption.

One of the reasons why the vast majority of pro studios have hard floors and soft ceilings instead of the other way around, is psycho-acoustics: the way we hear, and the way our ears and brains interpret sounds. We are accustomed to always be the same height above the floor, our entire lives, simply due to how tall we are. Our brains are well adapted to dealing with reflections coming off the floor, but not so well adapted to reflections coming off the ceiling, since ceiling height changes everywhere we go. So to our brain, everything sounds "right" when the floor is hard and the ceiling soft.

So, basically wanting advice on where to start with planning the acoustic treatment (assuming the fundamental concept is OK)... Am thinking I should buy some rigid fibre glass, make some corner bass traps, measure the impact and go from there?

There's a sort of "standard" method for treating rooms, which goes something like this: First, set up your speaker geometry correctly, such that the speakers are either flush mounted in soffits (best choice), or up tight against the front wall (2nd best), or at least 1.5m away from any wall (3rd best, but really hard to do in most rooms). The speakers should be mounted on massive, heavy, solid stands (never on teh console bridge, shleves or the desk), and should be decoupled with a suitable rubber pad (Sorbothane, neoprene, EPDM, etc), such that the acoustic axes ends up being 1.2m above the floor. Set up your chair so that your ears will be 38% back in the room (38% of the distance between the front and rear walls). Set up your speakers about 1 to 2 m apart, but also well away form the side walls, and angle them inwards at 30°, such that they are aimed at your ears. The acoustic axes will intersect a few inches behind the back of your head. Now set up thick absorption (4") on all of your first reflection points (both side walls plus the ceiling), as well as between the speaker and the front wall. Put thick absorption on the rear wall (6", spaced 6" away), and build large superchunk bass traps in as many of the corners of the room as you can. Now measure the room response to see how it is doing, in order to decide on the next round of treatment. Of course, you should measure the room response before you start installing any treatment, so that you have a baseline against which you can compare later measurements, to see what changed. That's the basic idea. - Stuart -