Sound treatment in an unfinished concrete basement

[Seashore]

I'm not 100% sure where to put this but I figured since it was recording-related it would go here. My family is relocating, and the dictates of available space have shoved my music gear into the basement. I don't mind the space, and I don't mind the insulation between the floor joists overhead because it damps down what could otherwise be some horrible sound reflections; but the floor and walls are unfinished, unpainted concrete. We're renting, so I can't build anything down there, and drilling into the walls is out. Gluing and painting are probably ok. I will be sharing the space with several spiders, who seem ok so far. Also sharing with the fuel oil heater, which is loud when it unpredictably turns on, which is a whole other thing.

I'm thinking about using some velcro or double-stick to put up my existing acoustic foam in the recording area, if it adheres, and probably making some plywood panels with either rugs or more acoustic foam that I can lean against the walls wherever possible. Maybe I can build some standing panels with weights on the bases. I already put down a couple rugs on the floor. It's a bigger space than I'm used to, which is neat - I'm guessing around 20x35 feet - so it doesn't sound harsh and tinny the way some small rooms do. I'm not planning on doing anything fancy, just economical stuff to cut down on reflections, that I can take down and hopefully take with me if we get our own place in the next few years.

Anybody have any experience with unfinished concrete? Any other suggestions for something on the cheaper side to take the edge off the room?

 

[ICTGoober]

The basics are to reduce reflections, right?
So you put carpets or rugs on the floor.
Hang curtains on the walls to trap the basses.
Add some furniture - scattered randomly.
Stack some empty boxes around (or fill them with foam peanuts).
You don't want any parallel hard surfaces, so go to work and keep it cheap!
Good luck,

 

[beaubrummels]

What Goober said.

I'll add you can make really cheap diffusers by getting thin masonite / press board and mounting it in a frame (ideally floor to ceiling) that causes it to bow, just by a couple inches, and put it in the center point of at least two perpendicular walls, e.g. one along the longest wall, one along the shortest wall. Then roll up some carpet, long/wide enough that when the roll is stood on end it goes floor to ceiling, and put that in each of the four corners.

Here's an example of what I did. It's not 100% effective (the diffusers and absorbers needed to go floor to celing), but it very significantly improved the sound.

 

[Securb]

Curtains would be the simplest and easily reversible. I bet you could find some on the cheap at Salvation Army in Salem or Goodwill in Hudson.

 

[JOLLY]

Padded moving blankets.

 

[Seashore]

Thanks for the replies folks. Lots of good suggestions. I just got back from a road trip up there with my oldest, dropping off more stuff and setting up his new room. I'll have plenty of empty boxes and probably some stored furniture and stuff to stack up. Love the curved diffuser idea too. I really wish the place wasn't so spider-infested, but if they're making new homes in goodwill curtains and packing blankets it's not such a big deal. Appreciate all your input. I will try to post some pics when I get the space up and running.

 

[GuitarStv]

The biggest problem with concrete basements is usually weird stuff going on in the low end. If you can stack absorbtion materials in the corners of the room (where two walls meet and where wall/floor meets) you'll significantly reduce the nodal interference that produces that. Then all you've got to worry about is high frequencies which tend to be easier to kill with a bit of carpet, some couches . . . basically anything soft.

 

[Seashore]

Thanks GuitarStv. The landlord has some stuff stored down there already, and I can probably shift stuff around and stack a lot of our extra stuff down there too. I usually catercorner my mixing setup and store stuff behind it, and I should be able to fill up the other corners too.

 

[Seashore]

An update - I'm about halfway through unpacking and putting up acoustic treatment in the new place. I got my amps set up, took out a couple of guitars, and quickly realized the guitars hate it down in the basement. It's really humid from all the rain we've been getting. I put a dehumidifier down there yesterday and it read 80% humidity. There's no central AC and no other air exchange down there, so I guess I'm stuck running this thing basically full time until (hopefully) autumn. Seems like moisture is going to be even more of a problem than sound treatment, yikes.

 

[Mincer]

That looks really good! Definitely a cool place to rehearse.

 

[ICTGoober]

Check that dehumidifer DAILY, or set it up so it drains into the sewer.

 

[NegativeEase]

Cheapest was to get basic control of a concrete space is carpet and go to Uhaul or Amazon and buy the thicker moving blankets and hang them off the walls about 1-3 inches.

​​​​​​https://www.amazon.com/dp/B0855GGQ5V...e-d73d10bbbb84

Get the Black or Red ones, blue vibes are weird for jammin' IMO

 

[Securb]

Looks cool but I want to know how many times you have banged your head on that black pipe?

 

[Seashore]

Check that dehumidifer DAILY, or set it up so it drains into the sewer.

I've had to empty it 5 times already. I'm not sure about the floor drain down there and not quite ready to take a chance on it yet, gotta test it further.

 

[Seashore]

Looks cool but I want to know how many times you have banged your head on that black pipe?

Ha, thankfully that one is a few inches overhead. But that pipe keeps me from putting up a drop ceiling. If I went under that I'd be hitting my head or my headstocks on everything.

 

[GuitarStv]

80% humidity is going to be hard on stuff - increased problems with corrosion, issues with wood swelling. If you've got an acoustic, keep it somewhere else. Usually you can plumb a dehumidifier so that it drains directly into the drain in the basement - that's the way to go so you can leave it on all the time and don't have to keep pulling the bucket out and dumping it.

 

[Fender_Punk]

Might be worthwhile to have 2 dehumidifiers just to ensure you get the humidity down and keep it down.

 

[Seashore]

Thanks... If it comes down to it, I will run two. We'll see. It's been unusually humid here with the insane amount of rain we've had. I'm running the entire studio off a single outlet so I'm not thrilled about adding another appliance. I've been running the dehumidifier and a circulating fan nonstop for a week and half, emptying the bucket 4 times a day, and recently it hovers around 50% as long as I keep up with it. I don't trust the floor drain. I'll get around to seeing if I can make it work at some point.

The cool thing is, with the fan and the air purifier and the dehumidifier going full tilt, it's actually tolerable down there. And they're far enough away from the amps that I can record close-miked parts with everything running. I think it sounds pretty good! The stacked boxes are working well to keep reflections down, but I'm going to try removing some of them and putting up more foam, because they're taking up a ton of space. I also have to make room for my painting stuff. Work in progress.

 

[Demanic]

What Goober said.

I'll add you can make really cheap diffusers by getting thin masonite / press board and mounting it in a frame (ideally floor to ceiling) that causes it to bow, just by a couple inches, and put it in the center point of at least two perpendicular walls, e.g. one along the longest wall, one along the shortest wall. Then roll up some carpet, long/wide enough that when the roll is stood on end it goes floor to ceiling, and put that in each of the four corners.

Here's an example of what I did. It's not 100% effective (the diffusers and absorbers needed to go floor to celing), but it very significantly improved the sound.

I jest, I jest.
Maybe.