Mastering Room Acoustics: Hitting the RT60 Target

Discover the secrets of hitting the perfect RT60 target in your mastering room! Join Matthew Poes as he explains what the RT60 target is, why it's important, and what happens if you miss it. Find out how room size affects the target and get expert advice on how to optimize your room acoustics. Don't miss this essential guide to achieving the best sound in your space! Subscribe to Matthew's channel for more insightful videos on acoustics and audio engineering.

[@lawrenceanderson5506]

A video on rt60 measurements would be awesome Mathew !! 😀

[@hi-fiklubben6750]

Another great video! When you get there - please elaborate on those type of absorbers that have the ability to keep the mids and highs lively. I think that is really interesting.

[@TheGwt3]

Great video!

[@brandonmccall9823]

Thanks!

[@PoesAcoustics]

Thank you, I really appreciate your support

[@ChadAV69]

Good video. I know exactly what you’re talking about when you said with a lower RT60 you will start localizing the speakers.

[@PoesAcoustics]

Glad that was understood. Very often when someone treats a room, the effect it has is perceived as better. It can be hard to realize that it might be too dead until you hear it "right". I run into that a lot. But the one thing that I find most apparent and so point out is the localizability of the speakers. I've heard some really high dollar setups with badly executed acoustics and the thing that stood out most was the speakers were obvious.

[@isak6626]

Thanks for an informative video! Would be great if you could mention measurements in SI units as well for us non-americans, e.g. cubic meters as well as cubic feet 😊

[@eisythetrackstud]

Really good explainer. Would love to see measurements compared to target. You mentioned average rt60. Should the rt60 vary, i.e. rt60 value at 20hz vs rt60 at 1Khz, etc. ? Is it like eq in that it can be preference and the target curve a 'house curve' based on that preference?

[@PoesAcoustics]

Probably not so much a house curve, but it will vary. The RT60 of a room depends on many factors and often we see the RT60 in the low frequencies rise dramatically. But its hard to fix and not really as big a deal. So a rise is considered acceptable.

[@miscreant1739]

My room is around .35 for the midrange and .2 once you get up to 7khz+. I think I need to experiment with moving my panels around and getting some proper diffusion to make it more even. Looking forward to more as always!

[@PoesAcoustics]

Sounds good. A lowering RT60 in the high frequencies can be addressed by replacing some absorber panels with panels covered in a wood front with a pattern in it. The RPG BAD panel was sort of the original, but slat panels work too. Inexpensive versions of these are made by companies like GIK. My prefered supplier is Real Acoustix, which I am a dealer for.

[@miscreant1739]

@@PoesAcoustics I may reach out once I figure things out a bit more. I'm going to pull everything out and add back a little at a time with measurements at each step to get a better understanding of what is happening. I've got my eye on those GuD panels too!

[@NakeanWickliff]

A worthwhile and pretty fun project. Just got done doing the same thing in my room.
@@miscreant1739

[@asx1248]

Hi Matthew, what is the formula for identifying what the target RT60 should be based on room volume? Thanks.

[@asx1248]

P.s. and does it vary also based on frequency? Below what frequency is it no longer applicable? Thanks again.

[@PoesAcoustics]

The formula is RT60 around 500 Hz = 0.3 x[(volume cu ft / 3531.34 cu ft)raised to 1/3 power], and then you have a range across 1/3 octabve bands. So at 63hz it might be around 150% of that value, at 8K its around 60% of that value. There is also an upper and lower tolerance for this, it doesn't need to be spot on. This gives a range of RT values that are acceptable for a given sized room.
There is no frequency where it is no longer applicable. But you allow the RT value to go up at lower frequencies. So by 30-40hz it can be twice the value at 500hz and sound ok. I suppose below 30hz it probably isn't something to worry too much about. Realistically, the RT time of a room below 100hz is more dominated by the rooms construction than your treatment. That won't always be true, you could certainly load up a room with bass absorbers, but generally speaking this is true.

[@CarlosGomez-THX_1138]

Please do the video on measuring and interpreting the RT60 sweeps. My room sound great after following OCA Audiophile's tutorial and adding a shelf filter to my miniDSP 2x4 HD. I would like to see a RT60 of my room.

[@PoesAcoustics]

I've been asked to do this a number of times. I'll work on this so I have something useful to share. I am sure that would be popular.

[@eisythetrackstud]

Yeah knowing what to look for in the measures and how to hear what the measures are showing would be super useful. You often hear the 'hand clap' test but how would that show in the measurements.

[@PoesAcoustics]

@@eisythetrackstud the hand lab test is kind of bogus. What matters is not the reverb of a handclap next to your head. It’s the decay of the source (your speakers) with the receiver (you or a microphone) at the listening area. Those will not and should not match.

[@northeastcorals]

@@PoesAcoustics It certainly would be :)

[@mikefranks2012]

Another vote for a video on interpreting RT60 measurements. 👍

[@emt999]

Trinnov Altitude gives you that RT60 number, how accurate is that?

[@PoesAcoustics]

its in the ballpark of what I get from REW. I find it to be a little lower than REW shows. But its similar. They have never shared with me how they calcualte it.
The advante of REW is that RT60 is not all that valid in small rooms as there rarely if ever is a period at which the sound is reverberant. However, it can be a useful metric of decay. As is EDT. What you can do then is look at the RT60 based on more robust methods, and REW offers the T60M method, which is a frequency domain method that is very robust down to very low frequencies.