How to Remove Echo From a Concrete Room

Patrick and I have recently moved into new homes in Puerto Rico, and we have each been building our individual studios. I knew removing the echo from my concrete room was going to be difficult, but I didn't realize it would be this hard. 

In our last studio in Puerto Rico, the echo was horrific, but at least the ceilings were made of drywall. In my new home, the walls and ceiling are concrete and the floor is tile. Before I moved anything into the room, it sounded like I was filming in a commercial bathroom. 

I had one goal with my new setup: I wanted to be able to sit down in a chair and start recording without messing with the camera or microphones. I could, of course, use a podcast mic in the frame, but I didn't want to see the mic, and I could have used a lav mic, but then I would have had to take it off every time I stood up. 

To build the set I wanted, I needed to place a mic out of the frame on a boom stand, and by moving the mic farther from my mouth, I knew I would be picking up more room noise. Sennheiser sent me their legendary MKH 416 shotgun mic, and I really wanted to produce sound to do this mic justice. 

I came in first and added rugs and curtains. I then started adding small sound panels and large sound blankets around the room. After a month of almost daily fiddling, I decided to add another sound blanket above my head. Even still, I wasn't able to remove the 100 Hz resonance in the room, but I was able to lower it in Premiere. 

What I Learned

Thin sound dampening items like rugs, curtains, and sound blankets do a great job of cutting high frequencies, but bass notes can easily pass right through them. To cut lower notes, You'll want 4-6 inch panels that are mounted 4-6 inches off of walls and ceilings. I made a really thick panel and placed it right next to me, and it did nothing to cut the 100 Hz resonance in the room. I assume this means that I would have had to put panels everywhere, and that was something I didn't want to pay for and something I didn't want to see in the background of my frame. Furthermore, I already owned sound blankets, so I made it work. 

There's no doubt that the sound blanket on the ceiling is an ugly addition, but it did cut the echo enough for me to get a nice sound with some help of an audio equalizer. 

If you're trying to treat a room for audio quality (and not dialog recording), bass management will be a much larger issue. Here's a video on some DIY treatment similar to mine. 

For ultra-professional advice, check out Acoustics Insider

Lee Morris's picture

Lee Morris is a professional photographer based in Charleston SC, and is the co-owner of

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Carpets and blankets everywhere wouldn't do anything for 100hz. Neither would thin acoustic panels. in fact those things probably have zero effect under 400hz.
The ringing at that specific frequency is happening because of your room's dimensions. These waves are exactly or half or twice...etc... the length of a room dimension, and they double up on each other, bouncing for many seconds. (Look up room mode calculator)

You'd need THICK corner bass traps at that frequency, or/and an absorptive wall splitting the room (at 1/4 length for example).

You could also achieve more with fewer items placed at first reflection points (DIY absorption panels, 2-4 inch insulation filled - cheap and fun to do - and they can be visually pleasing too, you can even print photos on the fabric you stretch over)

attached a pic couple of my DIY panels (note this thickness is not enough for 100hz either)

I’ve read this but If all of my treatment can’t effect sound below 400hz but a male voice is 85-155hz, how did it cut all of the echo out of the room?

Ok I might have been hyperbolic when I said zero, but still it's better and more efficient to cover the frequency range more evenly by using thicker treatment.
But what's more important is to hear what's really happening, which is that this is another clear sign you're supposed to move back to the mainland.

Great work! I totally relate to this struggle with bass; there's just no stopping it.

Your post-production settings made a HUGE difference and clearly I need to look into that! I'll add that CrumplePop EchoRemover works GREAT for those times when you can't properly treat a room.

Congrats on the new house and baby!! Glad y'all are still enjoying Puerto Rico.

Have you considered using an impulse file? An impulse file can be used to either add the dynamic profile of a space to a recording (i.e. you really want to sound like you're in the Sistine Chapel but you're in Puerto Rico) or you could remove the dynamic profile of the room you are in by creating an impulse file of the room and subtracting that profile. Be aware that this could create an extremely flat sound (as in very little recognizable environmental reverb). You might want to add something back so that it doesn't sound like you're in an anechoic chamber. The really cool thing about impulse files is you can create an impulse file pretty easily. You really only need a recording of a sudden sound like a clap in the space (with no other sounds) to start making the impulse file. Back in the day I made some in Cool Edit Pro (before Adobe bought Cool Edit and renamed it Adobe Audition). Still, you should still be able to do this in Adobe Audition. As with any digital signal processing, over doing it can create obviously manipulated results, but a light touch can be magical.

Would Apple Space Designer be a good choice for this? I have a terrible echo problem.

that's a lot of work. why not build a sound box with acoustic board to talk into? Then you can move it away when not shooting

Hi Lee, I love that your video hi lights an often overlooked part of video production.

It's great advice to work on the environment BEFORE changing equipment, and all the work you've done to kill the echo is fantastic.

No microphone will 'fix' a challenging location, so improving how the location sounds, gives you a great chance to collect great audio...

...However - using a 'shotgun' style mic like the MKH416 or MKE600 in an echoey environment works against the efforts you've put into improving the location.

I understand that you have more uses for the shotgun mic in other videos/locations, and it's a solid choice for most - but if you're building a turn-key solution, then a more 'cardioid' shape microphone pick-up pattern will definitely help you capture 'less' of the echo.

If you have to stay Sennheiser, then look at the MKH40/50, but really, any cardioid pick up pattern mic will be better than even a high quality and expensive shotgun. It's also an opportunity to select something like a larger diaphragm mic (Sennheiser MK4 is half the cost of the 416) if seeing it on camera is ok.

I really appreciate it when people take their audio seriously, and think you're providing some great advice, just wanted to give you a heads up that this is one of those rare edge-cases, where part of the set-up is working against your better efforts.

Cheers, Ian

edit - I just looked through the comments on youtube.

I completely understand that you have a workable solution and I applaud the effort - I would advocate for trying a less shotgun'y mic in the improved space, it might mean less eq work in post.

I've got a cardioid mic and I can't hear a big difference in this room between them.