Yes, specifically in the low frequency absorption coefficient. Anytime there is an acoustical test being done, regardless of the specific material, the test results with an air gap unanimously have a better low frequency absorption coefficient. This is why our corner straddled bass traps are built with an air gap as part of the design. Also, we tend to build our standard Acoustic Panels a bit bigger with the frame than the inner core - to achieve a similar effect - although less dramatic. Ultimately, if you made your acoustic panels thick enough, used the right materials and have them placed in effective positions you shouldn’t have a massive or dramatic reduction in performance (by not having an air cavity). Hopefully that helps clarify some things and gives you some peace of mind. Feel free to book a consultation if you ever want to start on another DIY project (just incase you have any questions beforehand) if anything just to make sure you’re going in the best possible direction before getting in too deep!

Awesome!! Glad it helped and thanks for the sub! Lots more to come..

Good question! Unfortunately, if the fabric is too thick, you’re not getting the full benefit of your absorption panels. I cannot give you a DEFINITE answer if I cannot see the fabric in person. If you observe that it isn’t “breathable” it may certainly be worth re-wrapping them. If you want to email me at [email protected] we can arrange you sending me a sample of the fabric through the mail and I can let you know for sure if it’s worth it!

@@NGAcoustics That would be very much appreciated. I'll write to you this evening. Thank you!

Sounds good!

Glad you found it helpful!

Yes, the impact of room dimensions on acoustics is crucial, but bass traps are valuable tools for managing problematic frequencies. They don’t necessarily "impoverish bass" but instead help to create a clearer, more accurate listening environment. However, the need for Bass Traps depends on the specific context in which you're using them. In some cases, a simple reduction in reverberation or rearranging your setup may be all that's necessary to achieve the desired sound in a room!

Absolutely, I agree with your perspective. Room dimensions play a pivotal role in sound reproduction, particularly in the critical low-frequency ranges. The interplay between room dimensions, speaker placement, and listener position can greatly influence how sound waves interact within a space. When we talk about the "best" room dimensions (for low frequencies) we are indeed referring to configurations that minimize problems like standing waves, resonance, and amplitude variations across the frequency spectrum - especially in the 20-150 Hz range. These ideal dimensions can help achieve a more balanced and even frequency response, which is essential for accurate sound reproduction. The concept of "Acoustical Dimensions" you mentioned aligns with this idea. Essentially, it suggests that certain dimensions will yield better acoustic performance by optimizing the room's modal characteristics. By selecting dimensions that promote favorable interactions between sound waves, you can reduce problematic resonances and improve clarity and definition in the low-frequency range. Which is exactly why we made or Rooms Dimensions Cheat Sheet: www.nextgenerationacoustics.com/products/room-dimensions-cheat-sheet Our cheat sheet is designed to be easy to use and understand, with a color-coded system to help you quickly identify good, cautionary, and poor dimensions. It's a must-have whether you're setting up a home theater, recording studio, or simply want to reduce echoes and reverb before you choose a studio room or build a new living room! Our download will help you optimize the acoustics of your room BEFORE you get in too deep! In practice, while it may not always be feasible to design a room with ideal dimensions, understanding these acoustical principles allows for better planning and treatment strategies. This knowledge can/should guide decisions about speaker and listener placement, as well as the use of acoustic treatments (like bass traps and acoustic panels) to mitigate the effects of less-than-ideal room dimensions. Striving for optimal room dimensions and understanding the acoustical characteristics of your space are crucial steps in achieving high-quality sound reproduction.

Absolutely, I agree with your perspective. Room dimensions play a pivotal role in sound reproduction, particularly in the critical low-frequency ranges. The interplay between room dimensions, speaker placement, and listener position can greatly influence how sound waves interact within a space. When we talk about the "best" room dimensions (for low frequencies) we are indeed referring to configurations that minimize problems like standing waves, resonance, and amplitude variations across the frequency spectrum - especially in the 20-150 Hz range. These ideal dimensions can help achieve a more balanced and even frequency response, which is essential for accurate sound reproduction. The concept of Acoustical Dimensions you mentioned aligns with this idea. Essentially, it suggests that certain dimensions will yield better acoustic performance by optimizing the room's modal characteristics. By selecting dimensions that promote favorable interactions between sound waves, you can reduce problematic resonances and improve clarity and definition in the low-frequency range. Which is exactly why we made our Rooms Dimensions Cheat Sheet: www.nextgenerationacoustics.com/products/room-dimensions-cheat-sheet Our cheat sheet is designed to be easy to use and understand, with a color-coded system to help you quickly identify good, cautionary, and poor dimensions. It's a must-have whether you're setting up a home theater, recording studio, or simply want to reduce echoes and reverb before you choose a studio room or build a new living room! Our download will help you optimize the acoustics of your room BEFORE you get in too deep! In practice, while it may not always be feasible to design a room with ideal dimensions, understanding these acoustical principles allows for better planning and treatment strategies. This knowledge can/should guide decisions about speaker and listener placement, as well as the use of acoustic treatments (like bass traps and acoustic panels) to mitigate the effects of less-than-ideal room dimensions. Striving for optimal room dimensions and understanding the acoustical characteristics of your space are crucial steps in achieving high-quality sound reproduction.

Great thought! What you’re describing actually exists and is commonly referred to as "room correction software". It works by using specialized algorithms to analyze the acoustics of your space, then adjusting the frequency output to counterbalance any problem areas like resonance or standing waves. It’s essentially the same concept as noise-canceling headphones but scaled up for entire rooms, especially in the low frequencies. In fact, the studio monitors I’m currently using, the ADAM Audio A7Vs come with built-in room correction software options, that fine-tunes the output based on the acoustics of the space they’re in. You can even "tune them" to the specific room that you're in (using something called "Sonarworks SoundID Reference software") which can significantly help, especially if you aren't working in a properly treated space! Another solid option with room correction is the ADAM Audio S2Vs - they also deliver precise, tailored sound - that adjusts to the room (with many different correction software options), making them an awesome choice for studio setups. My personal opinion is it's always best to use any/all of the tools at your disposal to achieve the best possible sound within your space. Check out this video I made for a deeper dive into the concept of "active room treatment" AKA "room correction software" and let me know what you think! kzbin.info/www/bejne/pYupgGZnh5mXmbssi=LCf7iK3RQ1wthcpi

@@NGAcoustics I've heard of room correction software that uses both targeted EQ and delays to tighten up sound. A live sound tech that ran sound for a band I played in used that type of thing at gigs. What I was thinking of is a set of subs in strategic spots with the sole purpose of playing any hot room mode frequencies back 180°out of phase, so the original sound comes from the monitors, hits your ears in your listening spot, and then gets actively canceled after bouncing off the wall by the speaker playing just that hot frequency back 180° out of phase

@@NGAcoustics I've seen some videos on big live sound setups where they do similar things with arrays of subs to help direct sound forward, and cancel rear reflections in large acoustic nightmares like arenas. I live in an apartment, and am not able to do any permanent installation, so I'm thinking of portable solutions for when I move into a better place.

It sounds like you're making solid strides with your room setup, and I love that you're already dialing things in with a spectrum analyzer and some strategic placement. The drop ceiling is definitely a great help for taming reflections, and you're spot-on in addressing some of those frequency issues. That said, a couple of things to consider moving forward: While the drop ceiling is excellent for controlling high-frequency reflections, it's not going to do much for lower mid range or bass/sub frequencies, which is where bass traps/thicker panels come in handy. You’ll probably want to beef up your low-end absorption in those corners, even though your boxed clothes are a creative temporary solution. They probably act more high-frequency/mid absorbers and aren't as effective at controlling deeper bass frequencies. Actual bass traps, or even extra thick acoustic panels, would likely give you much better results/control in those problem areas. Especially if you intend on doing any recording, mixing, mastering in the space. EQ and Spectrum Analyzer: It's awesome that you're using EQ to flatten out those peaks and nulls, but EQ is more of a temporary fix. It can’t address the root cause of acoustic issues, especially when it comes to low-end frequencies. Physical acoustic treatments-especially bass traps-are key for controlling bass and keeping your room sounding great at different listening positions. DIY Acoustic Panels & Bass Traps: For your next step, DIY panels and bass traps will make a world of difference. For panels, aim to treat your first reflection points on the sidewalls and ceiling. Bass traps should go deep in the corners (back and front if possible) typically the thicker, the better! (I'd recommend a 4in core for those). Since you're DIY-ing, let me plug in some killer acoustic fabrics that are perfect for wrapping your panels and traps - they’re breathable, durable, and look sleek! You can check it out here: www.nextgenerationacoustics.com/collections/acoustic-fabrics They'll make sure your panels not only perform well, but also look pro-level in your setup! Good luck breaking that writer's block! Keep experimenting, and you'll dial in that perfect sound soon enough 🙏

Very true!

I started in studio work in the 1960s. Ampex 350 stuff. Then in 1980 I bought a 24 track MCI tape machine from a studio and rented it back to them with a 5 year contract for the cost of the machine and the same in studio time with an engineer/producer. Then a Studer. Then I aquired a Neotek Elan 32 channel console from one of the Doobie Brothers who needed cash. I used to use the NEVE 8036, but the Elan had a good sound. That is how I learned multi-track recording techniques.

Wow! Thanks for sharing your story. Very cool that you got one of the Doobie Brother's consoles!

He had left the Doobie Brothers by then, but he was a founding member. Dave was the bass player.

Glad you enjoyed it bro!

Yes, good point! I agree 100%

Thank you for your input! You're right sub-bass frequencies (especially below 80Hz) tend to carry more and penetrate walls and structures far more easily than higher frequencies, creating noise pollution even when other sounds can seem "quiet". This is a big problem for those with heightened noise/sound sensitivities. I completely agree with your point on the dBA vs. dBZ weighting. The dBA scale, commonly used in regulations, de-emphasizes low frequencies, making it ill-suited for measuring the true impact of sub-bass noise. The dBZ scale, which measures unweighted sound across the full frequency spectrum, gives a much clearer picture of the intensity of low-frequency noise pollution. It’s aggravating that regulations haven’t adapted to reflect this reality, and it’s no surprise that this has been historically convenient for industries wanting to downplay the harm caused by industrial noise. As for your tinnitus, it's frustrating to hear that long-term exposure to noise pollution has likely contributed to its development. Unfortunately, early exposure to loud environments can have lasting effects on hearing health, and many people may not realize the danger until it’s too late. The fact that you were aware of the ringing sound from childhood suggests that exposure probably started quite early, and you’re not alone - noise-induced tinnitus is becoming increasingly common today, especially in large cities (and new construction prone areas). Your experiences highlight a need in our modern society for more awareness and updated noise regulation to better account for low-frequency noise pollution. Hopefully (with more awareness) we can push for a change that protect people’s (and the animals!) health more.

OMG you're right! I have been putting things together for a part 2 video and the Horns of Jericho definitely deserve a spot. I can't believe I had forgotten about this story - thanks for the reminder! What’s even more intriguing is the question of what the horns really were... Some "scholars" speculate that the sound described in the story may have been "symbolic" or maybe part of a "psychological war tactic". Others wonder if it could have been some kind of early use of resonant frequencies that caused the walls to collapse, similar to how sound is used in modern acoustic weapons to disorient or incapacitate enemies... Do you think the Horns of Jericho horns were "symbolic" or could they have been something far more advanced that we don’t fully understand yet?!?

Glad the advice resonated with you! It sounds like you already have some great speakers with the Revel Gem2's and optimizing for them now while keeping future changes in mind (like Barefoots, PMCs, or Focals) is a smart approach. Making your panel installation height correspond to the speakers (or even using larger/taller panels) will definitely help maintain optimal listening conditions, regardless of the speakers you choose down the road. I'm hoping that I can get a set of the focals one day myself 🤤🙏 Interestingly each of those brands you mentioned has slightly different sweet spot ranges in terms of ideal listening height & distance. For example, speakers like Barefoot often have a near-field sweet spot, while most PMC and Focal models benefit from slightly different height/distance adjustments (depending on the room’s acoustics and your listening distance from the speakers). Being able to change or modify your setup around your speakers (especially if you decide to change things up) will set you up for success. It’s awesome that you’re thinking ahead no matter which monitors you end up with down the road! Let me know how the setup goes or if you’re thinking about exploring some room treatments too! - Jacob w/ NGAcoustics.com

​@@NGAcoustics Nice to meet you, Jacob! Actually Jacob, since I wrote that, I did install most of the acoustical treatment I had ordered before I found NGA. I've put bass traps in the front corners only (12" wide, 4" deep, full 8' high, angled in the corners), and three 2x4x2" panels on the side walls with one panel also behind each speaker. I'm just waiting for delivery of four 1'x3' panels that I plan on putting above the double french door on the wall between the speakers, and on the soffit behind me where the ceiling drops from 8' to 7'. Even without those four new ones, the room is much better as regards to any slap echo I hear from where I'll be sitting. But the back of the room is still a little live if I want to record with a little bit of "room" in the entry niche. It's pretty interesting, and I probably should have taken measurements from a company like NGA, but after being an audiophile and a published AV reviewer for 20 years, I've sat in my share of hotel rooms where bass traps and self standing panels adorned the walls and corners. I did make sure to use a good mirror and make sure that both the speaker images either far back (near wall) and closer to the mixing desk positions were reflected in the mirror. The only thing I did skip was a cloud. I have a popcorn ceiling, so hopefully, it will refract some. Let me know if you would like any pics and we'll find a way to get them to you! Fred

Thanks man!!

Awesome, I just got back to you over email! Cheers friend 🥂

@@NGAcoustics Cheers mate, I’ve replied to you.

Absolutely correct!

Hi Sean, I’m sorry to say that there’s no perfect solution for completely eliminating the noise you’re experiencing. The most effective way to address this issue is to tackle it at the source. Unless you can move, some level of noise will likely always be present - due to sound transmission coming through the building's structure. You can (theoretically) reduce overall noise transfer by adding density and creating an air gap, but completely eliminating it is essentially impossible. Using “standard” acoustic panels or ceiling baffles is not necessarily the optimal solution for your specific situation. While they DO help reduce noise transmission coming from within a room, they are not as effective at stopping noise coming in from other rooms.. For a more custom tailored solution, we could design a high-density soundproofing baffle with plywood at its core, sound-absorbing material on both sides, and a sturdy frame. This would improve both density and absorption, possibly helping to lessen the perceived noise. Another option is installing an acoustic drop ceiling with a grid system and acoustic insulation in the space above. This can be effective, especially in rooms with higher ceilings (over 9-10 feet). However, it can be quite costly and less ideal for lower ceilings. I hope this helps you find a way to manage the noise issue effectively! Best regards, [email protected]

I think you might be better off with ANC headphones or ear muffs rather than drop ceilings, or acoustic panel installations. You'd have to cover the whole roof in order to have absolutely no leakage in sound which is cost prohibitive.

You are referring to “sound transmission” which can only be mitigated with construction. “Sound absorption” (which is what the video is about) is about containing unwanted reflections inside of a room.

Awesome thanks! Really glad it helped you!

Very cool! I'll definitely have to add that one into the Part 2 video we're making soon!

Here’s a link: ngacoustics.com/collections/acoustic-fabrics

Thanks! So long as the inner core is made from the correct material, either thickness would work wonderfully at the first order reflection point! The main differentiation between a 6 inch thick and 4 inch thick panel is going to be in your frequencies below 200 Hz. However, they should both provide full spectrum coverage at that depth! The audible difference between the those depths may even be completely negligible, depending on your room. You might find my new short video helpful on this topic. It covers how acoustic panel thickness affects frequency absorption: kzbin.info/www/bejne/qJuZiZmOhM6Ulbs

Who who 🎶 kzbin.info/www/bejne/hn_Fc3eomMp2r5osi=EHOxJhJ4MN60w0mB

Lol I feel your pain! People need to become more considerate (and aware) when it comes to environmental noise. Recently morning construction/digging nearby has been driving us mad! 😵‍💫You’re right! Light pollution is another BIG problem that often doesn’t get the recognition it deserves. It's time to raise awareness and take action for a healthier and better sounding world! 🌍💜🖤

the police violently shot people in my neighborhood at 1 to 3 am two times in the week or so leading up to the 4th of july so every time i heard fireworks for no reason in the middle of the night on june 30th it takes me a minute to realize it's not the police murdering someone in front of my apartment again.

Oh whoa 😧 That’s DEFINITELY NOT cool. Hopefully you still had a peaceful and safe 4th! 💜🖤

Citations and sources show on the screen as the video plays and are mentioned by the presenters. All of these facts can be Googled if you need any additional information or confirmation. Thank you for your feedback 💜🖤

The sources are shown on the screen

No problem, glad it helped! We’re using these in the test: ngacoustics.com/collections/column-slat-diffusers

Glad it helped. Haha thanks! I need to get back to doing more of those in the new videos. I still see good ones ALL THE TIME!!! 🤣

That’s a great question! Both of them are effective. However, the corner straddle designed bass traps (with a 16in air gap) are going to give you “more bang for your buck“ with less overall materials - the reason being (in all studies/ methods of testing) whenever any material is 16 inches from a wall/surface it has an increased frequency absorption coefficient - specifically in the low end. This concept is being utilized in the corner straddle design. Making them extremely effective. The full corner triangle bass traps are an older industry design/model - usually anywhere from 12 to 24 inches thick (to fill up an entire corner). Which is completely unnecessary - because IF you’re using the CORRECT materials, you will already get full frequency absorption at about 4 to 5 inches of depth and anything beyond that largely gives you diminishing returns. So, it’s essentially unnecessary, when you consider that it requires more material, costs more to build, would cost more to ship and after all of this, it wouldn’t even be “more effective“ than the other (corner straddled) design.

@@NGAcoustics thanks for reaching out please am redesigning ma home studio n i was wondering if i shuld put difussors or acoustic panel at the back wall ( actually i was tinking of designing ma own scatter face diffussor

Thanks Sean!!!

Literally, yes - that is the point here (and is addressed in the video). Because other metals tarnish overtime, lowering their conductivity. Thus allowing gold to retain its conductive qualities overtime much better than the other materials etc. Hopefully that makes sense and thanks for the comment. 💜 (See the infographic @1:37)

Was about to comment the same thing

You make an excellent point about the balance between functionality and creating a comfortable, enjoyable space for music. You're right! Carpet undeniably improves acoustics by absorbing high frequencies and reducing harsh sound reflections, yet nowadays many people overlook this benefit in favor of more modern, hard-surface designs. Adding bookshelves with a variety of books also contributes to better sound quality by acting as a natural diffuser, breaking up sound waves to prevent unwanted echoes. This approach can enhance acoustics while also creating a more inviting atmosphere. My personal reason for mostly avoiding carpet is the negative health effects that can come due to carpet mold, dirt and dust - not to mention polyester carpet shedding micro plastics into the air over time etc. It's also important to remember that if someone aims to create a professional-level listening, recording, or studio environment, they should invest in dedicated acoustic treatments. Random materials, while they can improve sound to some extent, are often unpredictable in how they affect a room's acoustics. Professional treatments are designed with specific properties to provide accurate and consistent results. For example, using specifically calibrated acoustic panels, bass traps, ceiling baffles and diffusers can ensure a controlled environment where sound is both pleasant, predictable and reliable. Your idea of merging acoustic treatment with personal, comfortable decor is aiming for an acoustic and aesthetic overall balance. Which I completely agree is ideal. Creating a space that enhances the listening experience while also feeling inviting should be the end goal. It's about blending sound quality with personal enjoyment, ensuring the room sounds as good as it looks and vice versa. Thank you for your input! Jacob w/ NGAcoustics 💜🖤

Wow awesome! Never heard that before. DEFINITELY going to look into it. The Aztecs have an absolutely fascinating culture. Maybe I can include that into a video I’ve been making about ancient War trumpets found in Tutankhamen‘s burial tomb!! Thanks for the info! 🤘

There are many scenarios in which a thinner panel is desired, even necessary! We don’t offer thinner panels on our website, but there are companies who do 1/4 inch thick panels, 1/2in thickness etc. and they are commonly used for day-to-day and commercial purposes. Often times for spaces such as classrooms, conference rooms, living spaces or anything else where they just need the excessive reverberation addressed and there is no need for the extra thickness. In these cases the extra thickness equates to extra unnecessary costs added on (to the shipping price, installation requirements, and unnecessary material expenditure). Not to mention, it’s very hard to discreetly work a panel that thick (such as 6in depth) into the architecture/aesthetic of many commercial spaces.

in essence, it is a bit more complicated. If broadband absorbers (porous absorbers) are the topic of this discussion, it is true, some might benefit solely from the use of thin panels which are targeted at "speech" frequencies (and above), whilst others would require a further coverage of the entire audible frequencies (Studio/home theater and such applications). Thickness is indeed an important parameter when planning a treatment strategy, but it is merely one factor of the equation. The material used, it's impedance, enclosure, spring (air gap) and angle of incidence (placement and positioning) would surely contribute to the overall effectiveness of the absorber. A futher suggested read about the quarter-wavelength (λ/4), Gas flow resistivity (GFR), porosity (pore diameter) and tortuosity would shed much light at the subject, and if already delved into it, a read of Viscosity, Friction, vibration and transmission in a porous medium would definitely assist in decision making. In short, usually, bigger is "better" for an application that requires it... Please keep in mind that broadband absorbers aren't the only option, and the combo of pressure/resonance treatment with porous/fibrous absorption could yield the desired results as well.

First time hearing/reading this. Most commercial bass traps are not closed off I believe.. could you explain why it should be? Would be highly appreciated

@@anthonymuc If you close to box to the wall the absorbtion coefficient lowers itself, if you just space the entire panel from the wall that open airgap won't lower the coefficient that much. Just something I learned form John Brandt and asked him myself about sealed or not because I was confused too.

This technically is false. I don’t really care what specific guru’s advice that you follow. I know directly from the manufacturer itself, that when they do the coefficient data testing, they do two tests. (One flush to the wall and then another test 16 inches from the wall) Regardless of the material being used, this is a uniform standard across the field of acoustic absorption coefficient data testing. And regardless of the material used, whenever it has a 16 inch gap to the wall, it has a BETTER lower frequency absorption coefficient. This is well documented/proven scientific data. This also works as a double whammy allowing for corner straddled bass traps to ship using less weight/material, while providing a lower frequency absorption coefficient. We have made full corner bass traps as well as bass traps with the air gap and have had success with both styles. However, overall it’s going to largely depend on the room that you’re in, the dimensions of the room, the other Acoustic treatments within the space and what frequency problems you’re currently experiencing that determine whether or not you need a bass trap like you’re mentioning. More often than not, a corner straddled bass trap (with an air gap) is an EXCELLENT solution. 👍

@@NGAcoustics I never said that if you don’t close the box the coefficient will not lower. And I also never mentioned that an absorber with an air gap performes better than an absorber which has the whole box filled. A full panel vs a panel with a specific air gap should perform the same if calculated accordingly. My 50 cm deep panels have 40 cm of material with a 10 cm air gap because they would’ve perform the same if they were filled. My 30 cm deep panels are filled because, due to the GFR of the material I used, they would’ve been less efficient at that specific depth with an air gap.

@panickedrobert What I’m saying is that you’re wrong based off of countless tests, scientific data and easily provable/searchable data. You specifically said “closing in the bass trap would increase the frequency absorption coefficient…” Which is patently false and unproven.

Awesome project! Sounds like you just need some good acoustic fabric and the materials to construct the frames at this point! Feel free to shoot me an email here: [email protected] and I can guide you through the process. Here is a link where you can get the best quality acoustic fabrics in the game: www.ngacoustics.com/collections/acoustic-fabrics

Fiber glass does nothing for bass traps

Interesting. Appreciate the feedback! Sounds like you could use some Acoustic Panels in your room to help fix it up a little bit sonically. Feel free to send a room analysis form or shoot me an email and I’ll try to help get your room sounding a bit better. I’m probably going to do a direct comparison video in the future so people can hear for themselves if the mic needs treatment or not.

Thanks for the insight! This is all very true, ESPECIALLY for acoustic pianos.

Hopefully I’m not too late!! It’s going to be okay 👊 Shoot me an email here: [email protected] and I’ll be happy to help you out. I can answer your questions and help you come up with a game to help your room sound great - regardless of the llimitations that you have currently.

Glad it helped!

Spot on! Yet, they still love calling these things “diffusers” all over Amazon, eBay etc! It’s madness out here 😵‍💫