What are /r/Acoustics' favorite Products & Services?

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Absolutely the following book: This is Your Brain on Music

This highly readable and engaging book discusses the nature of music, including a bit of theory, how we process music neurobiologically, and how we perceive music mentally. It's a must read...

I found them on Trustpilot and checked the ratings before i bought. They link it on their website: https://www.trustpilot.com/review/diffusor.at

Also a friend of mine who is a professional DJ, recommended it to me.

I can say that the bass trap makes a significant difference and the quality is superb.

Unfortunately i don't have the wave fuser, i bought the Slat Abfusers and Binary Abfusers and i must say my expectations were exceeded.

For the price i doubt you can find a better solution.

I noticed that the Dayton UMM is a condenser microphone. Is it normal for these measurement microphones to be condensors? I actually have a Bluebird condenser microphone that I use for recording vocals. Could I theoretically hook this up to my audio interface and just use this?

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What do you think?

I've been mulling this over and I think I'm kind of getting it. Critical bandwidth is smaller for lower frequencies which should allow us to 'hone in' better on those frequencies but this is partially negated because the distance between harmonics are smaller at low frequencies. It sounds like you're talking about the critical ratio rather than the critical bandwidth which might be a more useful metric in this context.

I found another source in Zwicker's textbook (page 119)

> for fundamental frequencies below 1kHz, the relative frequency difference becomes increasingly negative with decreasing fundamental frequency. For example, the difference at 60 Hz amounts to almost −3%, i.e. a pure tone, with a frequency of 58.2Hz produces the same pitch as the harmonic complex tone with a 60Hz fundamental frequency

he goes on to say that the pitch gets lower the less harmonics you include in the complex tone. This further supports why square waves sound out of tune because they're 'missing' half of the available harmonics.

Of course he doesn't explain why this is just that the effect exists. The search continues!

a loudspeaker or loudspeaker array can be designed to radiate in any effective manner. it depends on the design requirements of the system and the type of environment it is expected to operate in (open-field/anechoic conditions vs auditorium).

typically, due to the nature of HF frequencies having such small wavelengths, the sound propagation will indeed be much more directional. LF content has large wavelengths (10-55ft for 100-20hz - versus the diaphragm/cabinet), that the sound wave will radiate omni-directionally away from the source.

the radiation pattern or "directivity" across a bandwidth for a given loudspeaker or loudspeaker array is viewed from the 'Polar response' measurement/plot.

if you are interested further, i would highly recommend Bob McCarthy's book (https://www.amazon.com/Sound-Systems-Optimization-Techniques-Alignment/dp/0240521560).

pdf here: https://www.sendspace.com/file/1u4lm1

the "directional" characteristics of the loudspeaker/array is

Why not download an SPL metering app for your phone, and use the excuse of "research" to go out for a nice dinner?

Should note that decibel levels for things like this are tricky to capture, being transient in nature. You'd need a meter than can do sample-and-hold, and retain the highest reading.

Plus if it's 100dbSPL (assume a big metal spoon in a wok) in the kitchen it might be only 77dbSPL at your table 20 feet away. If there's 73db of ambient noise in the restaurant, you'd be measuring something that was barely audible. But if the place is quiet, say, 50 dB, that utensil sound would be subjectively much louder.

I totally agree (though I wish I'd cared more when I was younger). I currently wear these to gigs which work well but I prefer the feel of the moulded ones hence why I'd like to make my own.

Ah, YouTube videos all pretty much said to run water on them and let them air dry or run water on them, wring them out and then put them in a dryer.

https://www.amazon.com/Acoustic-Panels-Soundproof-Insulation-Absorbing/dp/B08B5Z539C?pd_rd_w=MNTbl&content-id=amzn1.sym.94349326-ca8a-4b0d-94f0-6931485b8573&pf_rd_p=94349326-ca8a-4b0d-94f0-6931485b8573&pf_rd_r=JZB46B70QEN88M4EWCJC&... I got these.

The people commenting on the reviews are kind of idiots and led me to ignore the 1 star reviews. All the 5 star reviews basically say 'everyone giving them a one star review didn't do it right'. But yeah, that's probably all I can do at this point I guess. I damaged one from putting the hair dryer too close to it, so I'll just cut my losses on that one.

Decoupling the bed from the walls and floors is where this problem gets solved, cheaply.

https://www.amazon.com/Silent-Feet-Anti-Vibration-Riser-Beds/dp/B00YSKSU7S#:~:text=Patented%20Sorbothane%20rubber%20creates%20a,bedrooms%20located%20near%20home%20theaters.

Heres some cheap feet that can help drastically.

These idiots saying 2% are going to change don't understand the problem and need to go back to audio engineering school as us with no education have solved this problem.

If it were me, I would just alter the box below to save time and make it look somewhat like it’s supposed to be there:

KIRIGEN Stackable Wood Storage Cube/Basket/Bins Organizer for Home Books Clothes Toy Modular Open Cubby Storage System - Office Cubical Bookcase Closet Shelves C26-DBR https://www.amazon.com/dp/B083NY7TLH/ref=cm_sw_r_cp_api_i_1S98XTNE3DYVGTN682RT?psc=1

I mean that it's more efficient as a sound isolator, which is what STL is about.

Consider the phrase "Sound Transmission Loss". Sound that isn't transmitted (conducted through the material) is energy that has either been reflected back from the material or turned into heat via absorption. IOW, "lost" - from the perspective of ears on the other side of that material. The more sound energy that's reflected or absorbed, the less is transmitted, and the more efficient the material is at stopping the transmission of sound.

Sorry if that was longwinded. Hope that helps. I'd recommend a good source of this kind of information - and a whole lot more - is The Master Handbook of Acoustics by F. Alton Everest. It's a great read despite being rather voluminous.

directly behind the monitors - put a monster panel - lying across- https://www.amazon.co.uk/GIK-Acoustics-700461538226-Monster-Bass/dp/B01H6VEUUG/ref=sr_1_1?crid=4M33S6HRT0E1&keywords=gik+monster&qid=1644267757&sprefix=gik+monster%2Caps%2C71&sr=8-1

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this would stop that effect of it being against the wall.

of course if you wanna do it properly - you would need the sides done and back wall - and corners with tri traps.

OK, thanks for the info. If I want to experiment with different carpeting/padding setups, is there a good way to measure how much vibration is being transferred to the lower level for any given scenario?

One weird thought I had was to stick a self-adhesive piezo directly on the surface of the floor (maybe in a few different spots) e.g. one of these (amazon link). Maybe measure the voltage coming out of it and convert to dB? I don't know anything about acoustics haha.

Any tips would be most appreciated :-)

Very useful, i'm managing to get it running on ubuntu (just now adding ffmpeg and i think i'm done).

BTW here's another paper[1] by the same author, within she gives fluctuation strength numbers for various sound types, maybe we should use them as a reference ?

[1]https://www.researchgate.net/profile/Stefan_Kerber/publication/51753264_Algorithmic_modeling_of_the_Irrelevant_Sound_Effect_%28ISE%29_by_the_hearing_sensation_fluctuation_strength/links/00b7d530924cc9f12d000000.pdf

I'll let the experts answer you're question. I think that steel is going to be very tough to dull the echoes. However if you decide to buy the foam, I just got some of this stuff: It's "2 inch" thick compared to the one inch that's sold a lot and this stuff took it's shape back well. If you read reviews on amazon a ton of people complain that different brands never puffed back up because they ship vaccum sealed. For value foam panels this stuff is good:

https://www.amazon.com/dp/B08TQBXSDP?psc=1&ref=ppx\_yo2\_dt\_b\_product\_details

>https://www.amazon.com/Dayton-Audio-DAEX25CT-4-Coin-Exciter/dp/B00M292316/ref=psdc\_10980771\_t4\_B00Q3M8PCY

Thank you for looking this up. It's honestly a great help.

Finding ways for people who want to inject the sound into resonant cavities has been a lot of fun. It's a great option to have a setup where the project can run without someone interacting with it. I really appreciate this suggestion.

I teach an evening adult acoustics class at a local college and use this text as an introduction:

Master Handbook of Acoustics, Sixth Edition https://www.amazon.com/dp/0071841040/ref=cm_sw_r_cp_apan_glt_fabc_AX3Z21E6WZENQ4JWMABY

Electro acoustics takes several forms, and it would be helpful to know the wavelengths you are interested in. Below are text that address audible frequencies. RF would be different texts.

Handbook for Sound Engineers (Audio Engineering Society Presents) https://www.amazon.com/dp/041584293X/ref=cm_sw_r_cp_apan_glt_fabc_HMZK0X413PQC38G4D0R0

Sound System Engineering 4e, Fourth Edition https://www.amazon.com/dp/0240818466/ref=cm_sw_r_cp_apan_glt_fabc_E70ER9C3SJXP0Q6MVF8Y

That's going to have some terrible flutter echoes across the width. At least the window and ceiling aren't flat.

As well as filling it up and a carpet and curtains, I'd use a localised microphone screen / booth like this:

https://www.amazon.co.uk/Microphone-Isolation-Absorbing-Reflector-Condenser/dp/B078WNW4YW/ref=pd\_lpo\_1?pd\_rd\_i=B078WNW4YW&psc=1

>els Sound Proof Padding, 14 X 13 X 0.4 Inches Sound Dampening Panels Used in Home & Offices（Hexagon,Black） https://www.amazon.com/dp/B0894CLK38/ref=cm\_sw\_r\_cp\_api\_glt\_fabc\_2ZPN5B53SH801QJ2XCNX?psc=1

What Fikle is looking for - The desk dividers def. won't help.

Dekiru might help but if they could help, us too.

"I can't hear it therefore it's not an issue" sounds like a pretty insane mindset to me lol.

If your only option is to convince that guy, I think there's a few ways to do it. The third one is probably the best:

1. [audible proof] You could potentially pitch up the original audio by an octave or two just to show that there is in fact noise being generated based on the data you already have. This way he could actually hear it (You could google how to do that in a free version of ableton)
2. [visual proof] With your mic hooked up to your computer, you could open up a spectrum analyzer in a DAW (like garageband or ableton) and show him the live readings which would show that there's a clear rumble in the low frequencies.
3. [visual proof] You can get a sound level meter like this one, which I personally own and I tested it on that audio you sent and it does in fact respond to that low frequency. This might be the best option because you can literally hand this to the guy and it's concrete proof and he could use it to test any improvements they try to make. A quiet room should be about 40dB. https://smile.amazon.com/BAFX-Products-Pressure-30-130dBA-Warranty/dp/B00ECCZWWI/ref=sr_1_8?dchild=1&keywords=sound+level+meter&qid=1619894347&sr=8-8

https://www.standupdeskstore.com/refocus-raw-acoustic-desk-divider-ash-gray?utm_source=google&utm_id=go_cmp-12514857999_adg-122038540074_ad-504958613923_pla-1190505094690_dev-m_ext-_prd-SUD-PET2116D-AG_mca-100779487_sig-CjwKCAjwg4-EBhBwEiwAzYA...

Or

DEKIRU 12 Pack Acoustic Panels Sound Proof Padding, 14 X 13 X 0.4 Inches Sound Dampening Panels Used in Home & Offices（Hexagon,Black） https://www.amazon.com/dp/B0894CLK38/ref=cm_sw_r_cp_api_glt_fabc_2ZPN5B53SH801QJ2XCNX?psc=1

Put the feet of the bed on rubber isolating pads to make sure that it is not structure borne noise causing the issue.

Isolating pads do not need to be expensive just something like these https://www.amazon.co.uk/Vibration-Rubber-isolation-UPE-Group/dp/B01MZ0ZVRD

They have to stick soft anti-scratch pads under chairs', tables' etc legs. It works perfect.

https://www.amazon.co.uk/Anti-scratch-Furniture-gliders-laminate-wooden/dp/B002QOFBI4

I also have kids and nobody complained. They are cheap and will eliminate majority of noises effectively.

Hi, Thanks for your help!
I've looked into tiles that go between the floor and the dance pads. Things like neoprene blocks and rubber gym tiles. From what I read online, these don't work much for dance pads. However, every thread I found was about having a pad on a second floor. :P The AV6 seem nice though! :o I like how they even have diagrams. Guess now I'll have to learn how to calculate the frequency of stomping on those pads.

Good thing with this idea is that it can be tuned over time.

Sound System Engineering (Davis/Patronis/Brown): https://www.amazon.com/Sound-System-Engineering-4e-Fourth/dp/0240818466/

Sound Systems Desighn & Optimization (Bob McCarthy): https://www.amazon.com/Sound-Systems-Optimization-Techniques-Alignment/dp/0415731011/

Before buying anything too expensive, maybe try and get a set of heavy blackout curtains or ones similar to the thickness of a hotel curtain. Even some cheap ones from amazon would be good to buy to see if you need something more extreme or if you can just get away with some thick curtains.

amazon

Obviously you might want something more stylish, but cheap curtains like these might be worth the $20 just to test out.

I really don’t think you would need much more then that, maybe even doubling up on a set of blackouts would probably be the most I could see you needing.

The approach is usually broken into two categories: transmission loss and reverberation.

Transmission Loss is a measure of how much sound (noise) is reduced through partitions (i.e. walls, doors, windows). Increasing the transmission loss of a partition is what most will consider as "blocking" sound.

Reverberation is a measure of the effect of reflections that occur when sound waves interact with walls, doors, windows, ceilings, walls. We can affect reverberation by adding sound absorption panels to a space. Reduction reverberation is what most will consider as "absorbing" sound.

You will need to study up on these concepts to understand why possible options/approaches will or will not be effective and what impact each option will have. https://www.amazon.com/Master-Handbook-Acoustics-Sixth-Everest/dp/0071841040

Most noise occurs during movement between classes, so we're less concerned about that hindering studying.

Step 1: characterize all noise sources that occur during class activity (from inside the building and outside).

Step 2: characterize the pathway for each of those noise sources.

Step 3: identify possible solutions to mitigate each source-pathway combination with predictions on effect after treatment.

So what we found online was initially this through Amazon - https://www.amazon.com/dp/B073NZ67LK/ref=cm_sw_r_cp_api_i_Qn1mDbFEHVGBE and then I actually found these at Home Depot that say in the description they can work for sound dampening... https://www.homedepot.com/p/LuxorWare-19-7-in-x-1-in-x-19-7-in-White-PVC-Fiber-3D-Wall-Panels-12-Pack-LW3D826/303607357?MERCH=REC-_-PIPHorizontal2_rr-_-205079515-_-303607357-_-N

Architectural Acoustics : Principles and Design is a good book on applied acoustics and would be a good choice for any kind of room acoustics consulting

https://www.amazon.com/dp/0137937954/ref=cm_sw_r_cp_apa_0B0mzbPJ8BD3Q

Do you think it's worth all of the trouble?

Will it actually dampen the sound enough or should I just move?

Also, The loaded vinyl would Ideally be attached to the door and the wall next to my head I assume?

Any thoughts on these?:

https://www.amazon.com/Mybecca-Acoustic-BEVEL-Tiles-Soundproofing/dp/B01BPS84F8/ref=sr_1_85?ie=UTF8&qid=1470112076&sr=8-85&keywords=soundproof

Would something like either of these two on my ceiling help at all?

https://www.amazon.com/Mybecca-Acoustic-BEVEL-Tiles-Soundproofing/dp/B01BPS84F8/ref=sr_1_85?ie=UTF8&qid=1470112076&sr=8-85&keywords=soundproof

https://acousticalsolutions.com/product-category/sound-blankets/

What's your knowledge of acoustics? Depending on where you're starting, see https://www.amazon.ca/Acoustics-Ducts-Mufflers-M-Munjal/dp/1118443128

Munjal is pretty much the top of the field wrt exhaust acoustics.

As others mentioned, there's software out there for this but if you don't know the theory, the software won't help much.