[AllanS]

There’s no shortage of DIY bass traps plans online that are variations of a fabric wrapped 4” frame around some form of insulation.  My guess is these will be effective above 125 Hz
I have a 11’ x 14’ space that needs help below 400 Hz but in particular a suck out centered about 70 Hz.
Is anyone familiar with lower reaching designs or a calculator to help tune traps?  I understand thicker traps will attenuate lower frequencies but would like to know how to tune the depth and air gap.
Thank you.

[jtcf]

In a small room the bass traps  you'd need would be so deep it would be impractical. If it were me I would treat the areas where I could hear strong bass build up by walking around close to the walls while playing bass heavy music.Many times it's one or two of the corners that are the biggest trouble spots,especially close to the ceiling. Then I would get an SVS subwoofer (with included equalizer) and adjust the bass modes with the app from my listening chair.SVS offers a long audition period so there's no risk.This link has a room mode calculator.Put the dimensions in and see a chart that shows exactly where you need to equalize.https://amcoustics.com/tools/amroc?l=488&w=488&h=244&r60=0.6

[ric]

https://www.acousticfields.com/how-to-build-a-diaphragmatic-absorber/

[AllanS]

In a small room the bass traps  you'd need would be so deep it would be impractical. If it were me I would treat the areas where I could hear strong bass build up by walking around close to the walls while playing bass heavy music.Many times it's one or two of the corners that are the biggest trouble spots,especially close to the ceiling. Then I would get an SVS subwoofer (with included equalizer) and adjust the bass modes with the app from my listening chair.SVS offers a long audition period so there's no risk.This link has a room mode calculator.Put the dimensions in and see a chart that shows exactly where you need to equalize.https://amcoustics.com/tools/amroc?l=488&w=488&h=244&r60=0.6

Thanks much.  I planned on supplementing with a sub once I tame what can be tamed but I hadn’t thought of listening for and treating specific areas.  I’m working on the front wall to supplement some corner traps that don’t go low enough.

https://www.acousticfields.com/how-to-build-a-diaphragmatic-absorber/

Thank you.  As much time as I’ve spent at Acoustic Fields bingeing on video and such I’m surprised I haven’t come across this.  I was tempted to buy their plans package but will start with free!

[WGH]

NWAA Labs and AV RoomService has products and research papers that explain low frequency absorption.

The NWAA Absorber Data Index has test numbers for each panel.
http://nwaalabs.ipower.com/index.html

Stereophile has an in-depth article about NWAA Labs if you haven't heard about them yet
NWAA Labs: Measurement Beyond The Atomic Level
https://www.stereophile.com/content/nwaa-labs-measurement-beyond-atomic-level


AV RoomService (the retail part of NWAA Labs) also has products and plenty of articles that explains bass absorption and reflections, also an important factor to consider in a small room. Settle in and read all the articles before buying anything.
https://avroomservice.com/

Check out their Frequency Response Panel System
"Effective down to 63 Hz. within only 2.5″ of depth!"

[AllanS]

NWAA Labs and AV RoomService has products and research papers that explain low frequency absorption.

Thank you.  I’ve read the Stereophile article a time or two but could certainly use a refresher.  I have been introduced to ARS but only got as far as the PolyFlex diffusers.  I completely missed their panels.