Home Studio Acoustics: The 38% rule (and why to IGNORE it)

Рет қаралды 10,702

8 ай бұрын

►► Fix the bass in your studio by finding your room’s low end sweet-spot. FREE guide → www.acousticsinsider.com/bass...
Learn how to build your own professional-looking broadband bass trap that works down to 40Hz and a diffusor front that keeps your high-end lively:
→ www.acousticsinsider.com/bbt-...
Have you heard about the 38 percent rule?
This is something that pops up a lot when you're researching speaker positioning, listener positioning and setting up a new room.
But I always thought this was really confusing when I first stumbled across this.
What 38 percent are we talking about here?
Is this talking about actually placing the speakers at 38 percent of the room?
Is it talking about the listening position?
When you dive into this thing it starts becoming really messy really quickly.
That’s what I want to clear up in this week’s video.
I want to explain to you what the 38 percent rule actually means, where it came from, what it's supposed to tell you and give you, and then show you what the limitations are and why there's actually a better way.
Related blog post on Acoustics Insider:
www.acousticsinsider.com/blog...
Resources in this video:
Harman Room Mode Calculator XLS: www.harman.com/documents/Room...
Wes Lachot on the 38% “rule”: repforums.prosoundweb.com/ind...
Acoustics Insider on Social Media:
/ acousticsinsider

Пікірлер: 37

@christianutter5383 7 ай бұрын

38% rule - I always skip the first 38% of youtube vids because that's where the real content starts.

@SHARt_murmur 7 ай бұрын

Haha well said!

@blammo5823 7 ай бұрын

Wadsworth's Constant

@christianutter5383 7 ай бұрын

@@blammo5823 Wadsworth's is only 30% =)

@brycesalvatore8581 4 ай бұрын

It really is a bit annoying how long these videos are. There is good information, but goodness let's get it out a little quicker. When I do finish a video, I'm always asking myself what took so long to get to the point and feel a bit confused. I appreciate the channel. Just my input.

@dougleydorite 7 ай бұрын

I ignore all these rules and also follow them. Measurements followed by listening tests have lead me down the right path over time

@dbrodbro1 7 ай бұрын

38% Rule implemented / moved listening arrangement 8" toward front wall / Bingo. Tears came to my eyes. Thank You Sir.

@lakambramusic 7 ай бұрын

Find a song with a good amount of sub bass. Bring it to your daw, find the tempo, loop 2 bars where the bass is good, move around the room….

@veenhond 7 ай бұрын

nice one. after going down the rabbithole of fixing bass problems i decided to just put my table back where the room sounds best. so i inadvertently used some of your bass hunter technique, and i can recommend it!

@paulward1586 7 ай бұрын

As usual, great content.

@ThrillaPark 7 ай бұрын

Thank you

@Big_Old_Bondy 7 ай бұрын

Very interesting how the axial mode is skewed across it's length, due to the delta between the front and back wall boundry density. Great video 👍

@Big_Old_Bondy 5 ай бұрын

@@chinmeysway Yeah maybe one of those things you don't really notice. My current setup has a door in the front right corner and the left is solid wall/plaster. Still sounds fine and imaging is good. I listen at very low volumes anyway so I don't excite the room too much.

@mastablasta9x 7 ай бұрын

Hi Jesco, could you reveal if you plan to do some black friday deal on BBBT course? ;)

@RogerBadgerDSFlyer 7 ай бұрын

Would a listening test like this work better by playing some sustained synth notes, like a basic sine wave, at various low end frequencies, say E0 (20.6Hz) through E2 (82.4Hz)? Might be easier to detect changes as you move around when there is a constant level, same frequency, sound emitting.

@nitinvaid89 7 ай бұрын

i have 11x 20 Ft room and have ringing bass issue at 30-40hz over 1 second and i have hard time fixing this which trap i can make myself? been watching all your videos but not able to get exactly what i want

@roninthegoat2810 5 ай бұрын

Does my room sweet spot change when I change speakers? Like if I do the bass hunter method with the monitors I got now and then switch to a different one do I need to do it all over again?

@BrentLeVasseur 7 ай бұрын

What’s your take on active bass traps like the PSI Avaaa or using a quad subwoofer array, where you have 2 stereo subs on the front wall playing in phase and two on the back wall playing 180 degrees out of phase to cancel out room modes and eliminate humps and null spots?

@Cautionary-Tales-Band 3 ай бұрын

It's a thing. Pairs of subs in the correct place essentially interact with the room modes with inverse polarity, so can cancel out certain room modes.@@chinmeysway

@Jrel 7 ай бұрын

On the first diagram, you actually pointed to 7.5 feet of the length of the room, which is 31%. 38% is at 9.12 feet (9 feet 1.44 inches). I'm guessing the 7.5 feet is better? The 38% mark or a little past 9 feet is close to the 4th standing wave (yellow) null. Unless the 4th axial mode doesn't matter much? If that's the case, then the 38% position is fine? (in the 2nd diagram, the person is sitting very close to the 38% position). There's only 3 axial modes showing in the 2nd diagram. Added: Oh I see using the Bass-Hunter technique, that is probably just the best way to find the listening spot.

@iandeegrees1509 6 ай бұрын

Do you assume that the speakers are positioned at the wall or slightly off (roughly 30cm 40 cm)

@sawcp 7 ай бұрын

I always put the speakers at the mid point of the length of the room and both speakers touching the side walls. Based on measurements, this seems to excite less modes. And based on listening test, this placements always has wide soundstage with good clarity.

@paulk9534 5 ай бұрын

Really? You must have a really long room if you can sit so far back

@sawcp 5 ай бұрын

@@paulk9534 just normal square-ish room, 3.6 * 3.2, I sit 0.6 m from the wall. Pretty nearfield but sounds good to me.

@PatMcGuireMusic 7 ай бұрын

The first speaker in the corner, should this be on the floor or a stand at ear level? Thanks.

@theaudiovisuallab677 7 ай бұрын

Floor

@PatMcGuireMusic 7 ай бұрын

@@theaudiovisuallab677 Thank you so much.

@venkydc6874 7 ай бұрын

Hi....my bass sweet spot is above the speakers 2-3 feet in front of the sitting spot (equilateral triangle). How to address this ... please help

@KaneDWilliams 7 ай бұрын

To use his bass hunter technique. You must find the sweet spot with the room empty and that becomes your listening position. You then place your speakers in respect of that seating position.

@has_hash 7 ай бұрын

Starting point 38% from the front outer perimeter wall... Before any acoustic treatment. This is something many miss.

@sigurtsigurt549 7 ай бұрын

Finding the best position by ear is nonsense as you do not have a proper reference just the sound you used to listen which could be completely off, so take several measurements is muuuch better way how to do that..

@zerobject 7 ай бұрын

Maybe it's best to combine measurements with listening impressions then. At least this is what Jesco showed us in his earlier videos.

@KaneDWilliams 7 ай бұрын

He is saying to take multiple listening tests, with various pieces of music. If measurements was easier, he’d say to do that as he also takes measurements whilst adding treatments. Remember, this is only about listening for a balanced low end, not the entire frequency range.

@sigurtsigurt549 7 ай бұрын

@@KaneDWilliams listenig and judge if low is balance when you never hears it before in proper room doet no make sense..no matter how good you know the track..

@KaneDWilliams 7 ай бұрын

@@sigurtsigurt549 ok, well you may as well stop listening to Jesco’s advice as this is the basis for his whole approach.

@sigurtsigurt549 7 ай бұрын

@@KaneDWilliams there still space for impruvment

@andynonimuss6298 5 ай бұрын

The 33 and 38 percent rules are not universal to all rooms. In a room that is 30 feet long, at 38% the Listening Position would be 11 and a half feet from the front wall and your studio monitors would be 7 and a half feet from the front wall. It would be ridiculous to have your studio monitors and your Listening Position that far away from the front wall! No studio would ever do that. In contrast, if you had a room that was only 7 feet long, at 38% your desk and studio monitors would be crashing into the front wall! In a room that's only 7 feet long, your only option is a Listening position at 45.8%. If you map all of these things in a CAD program you can clearly see that 33 and 38 percent ONLY work for rooms within a specific length range. And to be technical... the midpoint distance between nulls is not 33% it's actually 32.8% and 38% is actually 39.6%. Most smaller room lengths will have a Listening Position at 45.8%.