Tracking Room Acoustic Treatments

[treatmentroom]

Hello!

I have gone through the "Read this First" and think I have everything covered. Please let me know if I've left anything out.

I just finished moving into a new studio space. The control room sounds great and has nice acoustic treatments. The tracking room, on the other hand, is a completely blank slate. The room dimensions are 26'x19'x11'h with drywall walls and ceiling and a painted concrete floor. I will be tracking everything from drums to vocals and acoustic/electric guitar but almost never more than one instrument at a time so iso booths aren't important to me. I would prefer to keep the room open and not divide it up. I typically use gobos when I need things to be tighter sounding. I will probably end up having a few "stations" around the room. I have a pretty big collection of drums, guitar amps and synthesizers/keyboards so I would like to make little areas for each.

My overall goal is to make a tracking room with nice balanced acoustics that has "a sound." I use lots of room mics and prefer rooms that aren't too dead.

I currently have about 30 - 2'x4' sheets of 2" 703 and 4 - 4'x8' sheets of 2" 703 available. I have a full shop and I'm open to building anything. Within reason, budget isn't a huge concern but time is. I'm trying to focus on surface mounted treatments or hanging treatments since I am just leasing the building and may want to take some of this with me when I buy a building or move to a new spot.

I'm considering starting with absorption panels on the long walls with the 4 - 4'x8' sheets of 703 and maybe 4-6 panels on each of the short walls with the 2'x4' 703 to start taming the reverb in the room. Based on the Reverberation calculator that should bring the RT down from 2.8-3.2ish seconds to 1.5-1.7 seconds which seems more manageable. Then I'm thinking about building some type of diffusion treatments between those absorption panels on the long walls. On the ceiling I need to build something to break up the huge flat surface.... preferably with some lighting built in. FYI if you are looking at the layout below there will also be some exposed duct work going down the right side of the ceiling.

Am I on the right track with any of that?

Any specific acoustic treatments that you guys recommend in this room?

Thank you all! I have learned a lot from this forum!
Here is the basic layout of the studio.

New Studio Layout.jpg

[treatmentroom]

Please let me know if I didn't put enough info into the first post or broke some rule.

I have started on some acoustic treatments. I'm building 4 4'x8' absorption panels for the long walls first. I also built a little lighting. They are a simple bank of recessed lights flanked by 2'x8' absorption panels.

IMG_7153.jpg

I'm considering building a few "convertible" treatments to be able to vary the sound of the room. I'm thinking of a 4'w x 6'h x 6" deep wooden box that opens similar to a double door refrigerator to create a 8'w x 6'h absorption panel. Then, I can tailor the acoustics in the room and even change them for specific areas.

Even though this isn't acoustics related, I was able to finish my rack which gives me motivation to get this thing finished!

IMG_7263 (1).jpg

Any wisdom or insights into other acoustic treatments would be appreciated.

[Soundman2020]

Hi there " treatmentroom", and welcome!

I have gone through the "Read this First" and think I have everything covered. ... Please let me know if I didn't put enough info into the first post or broke some rule./quote]You did just fine! The delay in response is nothing you did: It's me. I'm the only one helping out with advice right now, and there's a lot of active threads. I just hadn't gotten around to yours yet...

Anyway:

The control room sounds great and has nice acoustic treatments.

If you want to run a set of tests in the CR using the REW acoustic software package (free!), then I'd be happy to analyze the results for you, and see if there's anything you can do to improve it even more.

I will be tracking everything from drums to vocals and acoustic/electric guitar

That's three rather different scenarios! I would suggest that you adopt one of two approaches: Either make "zones" in your room that have different acoustical response properties (such that you can change the sound of an instrument by moving it to a different part of the the room), or design "variable acoustic" devices that you can swing, slid, flip, rotate, open/close to change the sound of the entire room, or parts of it. OR you could do both.

At nearly 500 ft2 and 5500 ft3, its a very nice sized room.

My overall goal is to make a tracking room with nice balanced acoustics that has "a sound." I use lots of room mics and prefer rooms that aren't too dead.

While "live" is certainly better for drums, piano, brass, percussion, and several other things, it ain't so great for vocals and acoustic guitar. I'd suggest having a deader section in the room, or the ability to make one section deader when needed. In fact, setting up drums in an area that sounds a bit deader than normal but then putting room mics in the liver part of the room to add into the mix, can produce a nicer sound than just having the drum kit out in a fully live environment. You can be more creative if you either have zones in your room, or you make it variable.

I currently have about 30 - 2'x4' sheets of 2" 703 and 4 - 4'x8' sheets of 2" 703 available.

That's a good start, and will certainly all be used, but before you actually build anything it would be ideal to first design the room acoustically, and decide what you want where, and how each part should sound.

I'm trying to focus on surface mounted treatments or hanging treatments since I am just leasing the building and may want to take some of this with me when I buy a building or move to a new spot.

No problem. It can all be removable.

I'm considering starting with absorption panels on the long walls with the 4 - 4'x8' sheets of 703 and maybe 4-6 panels on each of the short walls with the 2'x4' 703 to start taming the reverb in the room.

[/quote]That would make the room sound uniform, the same all around, and it will only partially tame the reverb. Also, are you SURE you want to kill all the reverb? The "sound" of a room is very closely related to the reverb. Or rather, it is related to the relative relationships between the decay rates of each frequency band, and the decay rate of the room as a whole. Instead of killing that the same all over and making the room into one large box that sounds the same everywhere, it would be better to have the ability to adjust the decay rate independently for different frequency bands as needed, to give you maximum control and maximum flexibility.

Here's the acoustic analysis plots showing how the decay times change in a small room (vocal/guitar), using two large variable acoustic devices on the walls, that I designed a couple of years back:

vari-room-rt60-plots-all-positions-t20.jpg

As you can see, the changes are not huge, but they are still rather interesting and very useful. As the panels are opened/closed, the room becomes either brighter or duller: With the panels fully opened, the room is a light brighter, emphasizing high end of the mid range and the low end of the high range, while simultaneously killing the low range. When they are fully closed, the opposite happens: the room becomes "warme", "richer" and maybe "boomier", with more life in the low end and less in the mids and highs. By opening the panels part way, you can get pretty much anything you want in between those two extremes.

Based on the Reverberation calculator that should bring the RT down from 2.8-3.2ish seconds to 1.5-1.7 seconds which seems more manageable.

1700ms is still rather long for some instruments, and for vocals. Fine if you want to record Gregorian chant, or a cathedral choir, but not so great if you want to record a breathy romantic ballad, or intimate solo. For a room that size, I would shoot to make it variable between maybe 800ms and 2000 ms, to cover all bases.

Then I'm thinking about building some type of diffusion treatments between those absorption panels on the long walls.

Once again, you are talking about making the room uniform all over, with no variability. That's only good if you only ever plan to record one genre.

FYI if you are looking at the layout below there will also be some exposed duct work going down the right side of the ceiling.

How will you isolate that? "Duct work" implies HVAC. "exposed duct work" implies "noisy HVAC". You don't want noisy, resonant things in your live room! The air flow velocity inside duct work is usually high, creating both air noise and also vibration in the duct itself, as well as carrying sound in from wherever that duct comes from. That needs to be isolated, and silenced. Yes, you absolutely do need HVAC in the room, but both the supply duct and the return duct need to be suitably designed and treated, such that the air flow velocity into the room at the registers is well below 300 fps, while the air flow volume is still sufficient to maintain at least 6 room changes per hour, and the noise level in the room with the HVAC running does not exceed NR-20 (or NC-20, if you prefer), and even better would be NR-15. Those are the normal design criteria for recording studios. You won't be able to achieve that with an exposed, un-isolated duct in the room. Your mics will pick up all of those ugly sounds, very well.

Any specific acoustic treatments that you guys recommend in this room?

Yup! Variable ones, carefully designed and carefully placed...


- Stuart -

[treatmentroom]

Thanks for the thoughts Stuart!

Did you happen see my second post? Variable treatments was exactly what I was leaning towards. I'm now considering using 4 4'x8' panels to create a dead corner that I can use along with gobos for vocals and any instruments where I want that sound. Then building some variable treatments and putting them around the room to where I can open/close the doors to taste.

What do you think of something like this? This sketch is just a cross section obviously. They would be braced in a way that there would be no resonance from the plywood face. I'm thinking that closed they would be 4 feet wide and 6 feet tall. Then open it would be @8ft wide.

Variable Treatment 1.jpg

Are there any threads on the forum you would suggest that used variable treatments?

As far as HVAC..... I said exposed duct work but that was probably mis-leading. I have a friend that has designed/installed the A/C in most of the newer large recording studios here in LA and he is doing it for me. He has assured me that he can get adequate airflow into the room with no noise and no crosstalk between the rooms.

I will definitely do an analysis on the control room once I get the other room going. I have some projects coming up very soon so I need to get the room to a usable starting point and then refine from there.

[Soundman2020]

Or maybe something like this:

Variable-Acosutic-Module-halfopen-SML.jpeg

That's one I designed for a customer in the USA. That's the one that has the effect in the graphs I posted previously. It's a tuned device, of course, that does several things...


- Stuart -