Hello everyone. I'm starting to build a small production room to mix and record vocals and some overdubbing.
Room size is L5.6m x W3.5m x H2.17m. I have already three designs that it might work acoustically and fit my budget.
I was looking everywhere for a information on sawthoot design sometimes referred as Jansen room design but I couldn't find any helpful information. The reason why I want to choice this design is that it can be used for both control room and live room. Question is if this design could be better to absorb bass frequencies and if this room can have better acoustics characteristics then two of my another designs. (I'll post them soon).
I use this when it fits and to very good results (see Mixer Mark in build diary for one example and my site for others). It does work well in rooms of your width. I always heavily trap the ceiling (high percentage of coverage). It does need supplemental trapping from front corners or other areas. It (the sawtooth model) does open up multiple options for the rear wall from absorption to diffusion or even reflection.
You would have to post your three options (as you mentioned) to receive an opinion on what might be best.
Hey Jeff. Thanks for a post.
So those are my three ideas.
First is already discuss sawthoot design. Where room is from one side absorbent and facing wall could has more options as Jeff said. From opposite side more reflective with absorbent facing wall. In four corners I'll place absorption for LF. Question is if I should fill up air gaps in those corners with more wool to get better absorption or air gap is ok.
Second design has heavy absorption in a half of room which can be regulated by adding more reflective surface to experiment. This design has two versions a that is a question. Should i change angle off back of panel wall - hardboard, not to have them parallel with opposite facing hard board? And is a advantage has this heavy treatment in middle off room?
Third design is mirrored of previous design. This way I might save more space on inside bud I'm not sure if the depth of absorbent wall is enough. I'm planning to use 100mm tick mineral wool with lower density and on top 20 mm tick rock-wool (with high density). So total of 70 mm tick I guess.
Floor will be sitting on wood frame filled with polystyrene with 22 mm tick OSB boards.
For a ceiling I might use wood cemented board as mineral wool sandwich or just floating clouds.
Thanks for any suggestions.
As someone who also records and mixes in the same room of similar size I find it hard to hear the mic'd source without wearing iso headphones and going out side. A real pain, so record a bit and have a listen back, a real pain and a lot of trial and error. I do not like recording this way at all.
The live room sound I feel is more important in a dual purpose room.
By that if you have the band in there and you want to deaden the noise.
If it is mainly tracking vocals the design doesn't need to be as sound proof.
My advice is for a room that size to go foe design 3 as the most practical for that width of room.
I would presume the outer walls are double brick, so it is best to get as much absorbency as you can, the design looks like you are isolating the sound.
You can put up movable reflective panels (diffusers) afterwards to add some life.
If there are no Amps being recorded and mainly vocals, acoustics instruments you might be able to make bass traps, absorbers and diffusers to treat the room enough to get a room that also is acceptable to mix in and save yourself a mammoth task.
------------------------------------------------------ A great mix is created at the source
A compressor is a "voltage turn it downer".
You can determine when it begins to turn it down and when it resumes from turning it down, even how quickly it does it's "turn it down" and by how much it turns it down so you can push more voltage into it to be turned down and then make up for gain lossed from turning it down.Bart Nettle
sawtooth treatments are very nice especially if you make them as discrete components which can be built up over time, re-used, or moved later. or built as an integrated set with your LF trapping is also workable. if not going with the sawtooth, then #3 would be a good choice. and typically you will need to track with headphones if you have performers in the room.
I think to be able to reply to your questions it would be helpful to step back and ask one at a time. The whole context of your room is not available, therefore it's really not possible to comment.
Glenn, beautiful work as always!!
In support of sawtooth here are images, test data and even a sheet from the document set from one of my rooms: FMG in Chicago. This is their Studio B and the data is the set of PMC's. As with all of this stuff the details are important. But the materials involved are very simple.
i prefer to use a 2" 3pcf layer on the cloth faced units and light back fill. on the units with slats, just light fill will do it. on the large front and back wall absorbers - rigid face behind the cloth and light back fill. in your room, the low ceiling will be tough. i'd consider a large ceiling soffit front and back where you won't be standing to provide more absorption and depending on your HVAC arrangement use the soffits for the air exchange ducts etc
maybe the process or awareness of the sawtooth option is as important here than a specific "recipe". There are variations of this theme (thanks again Glenn) and its not that the details don't matter...but there are many threads about different room models that can't apply to many "guerrilla acoustics" situations. Yet here is the little "sawtooth guy" standing in the far corner of the room and no one really notices him. It is a viable option that has benefits across the spectrum.
Providing you trap the two front corners and the ceiling heavily, this approach shifts the burden of heavy duty trapping on the rear wall.
The room I shared is not heavily bunkered for isolation and is in a building that is honestly poorly built wood frame. My point is that more LF energy is passing through these walls than would in a ground up situation. The system I shared was right for that instance. With more mass in the walls...variations of the sawtooth panels and/or tuned traps would be in order.
Hey. Thanks to everyone for great input on the topic!
jinksdingo, I'm aware of tracking sessions from outside with headphones or on second monitors. There is not much to do about it. Did you use bass trap in your room?
Glenn my HVAC is just central heating radiator and ventilation thru wall outside. So I might just make a few panels from rigid wool and hang it up?! And you are right about making sawthoot from a components. I like that idea so I have one more design to present.
so for the air exchange you should consider the impact fully - moisture, energy conservation, # of air changes per hour, and so on. bare minimum you would want an isolation baffle box and vent fan to push/pull air to the flow is maintained and extending that, some humidity control and ERV type unit to minimize the energy loss because of temperature differences between your room and the outside. if you have not already obtained a copy of Rod's book (Home Recording Studio: Build It Like the Pros: Rod Gervais: 9781435457171: Amazon.com: Books) which has an excellent section on HVAC to get you started (and hopefully inclined to then speak with a licensed person to ensure you get what you need), it's strongly recommended...
Design #4 is constructed from 3 to 4 panels of dimensions H2000 mm L1000 mm W100 mm on each side of room and bass absorption in corners. I guess with this options I'm able to move them around to create any of previous models and of course experiment. I would like to ask you guys, should I put reflective surface or just fabric instead of question mark. I think fabric is just fine.
Jeff great of you sharing drawing, graphs and more information. I know I'm asking to many questions in no order. Context is something what I don't have because I think I have lack of knowledge and experience in this field. I know just some theory from books and GS threads. I also know that size of my room is more then small. I'm wondering what you think about last design. Any advantage of leaving air gap behind panels or just waste of space.
Hello OJan and you are certainly welcome. And I could be more clear in my reply to you asking for "context". I was simply meaning that a more complete plan view drawing with all your room dimensions and unique factors would help.
As for the air gap behind "teeth", in my experiences a small gap (meaning they are not completely sealed) is fine, but I suspect that once you pull the teeth that far away from the surface you could actually loose some of the LF control of the incident wave (initial wavefront from speaker toward surfaces). THIS is one of the key benefits of the sawtooth approach that I've experienced...meaning the sum is much greater than the parts. I make an analogy that the teeth work like a great offensive line in American football, the benefit is the unit and they work as a team (blah, blah huh).
+1 to Boggy's work. I really dig that teal. I like going to fabrics in the "blue" range. I think it can create a great vibe and this certainly does.
To Peter, they sawtooth panels work as membrane absorbers but it is definitively a system effect at play. You need the sequence of units for this to be effective and you need to be able to implement this symmetrically on both sidewalls.