Questions tagged [acoustics]

Acoustics is the interdisciplinary science that deals with the study of all mechanical waves in gases, liquids, and solids including vibration, sound, ultrasound and infrasound. Applications of acoustics are for instance the audio and noise control industries.

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26 views

Passive speaker

I’m working on a project for a cabinet with a passive speaker made out of wood I was thinking about 4-6 holes for it, and I would like to close-open that holes to raise the volume or turn down the ...
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1answer
47 views

Acoustic treatment - Bass Traps w/o drywall?

I'm about to frame/drywall a room approximately 18 x 14 x 9 and acoustically treat it. I plan on using rockwool insulation for its acoustic properties, fire/waterproofing etc... It's my understanding ...
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Interior ceiling sound insulation

I have a room where very loud sounds (140-160dB) are going to be produced on an occasional basis. I am trying to acoustically insulate the ceiling with the materials I have in my regional warehouse. I ...
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2answers
35 views

Setting up Home Studio, need advise on setup

I am setting up my home studio (I am mainly a music producer, produce hip hop / trap beats). My present setup is as shown in image 3 which is not giving me the perfect results. I have 2 ideas that is ...
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80 views

Help understanding sound wave interference from two sources as a function of distance and frequency

I am trying to optimize the acoustics of a room in my house for music listening. I use a computer that runs a free app called, REW (room Equalization Wizard) . This app can play a test noise through ...
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3answers
78 views

What sound is best for measuring which frequencies a wall is reflecting?

I am recording in a very large room and getting sound reflections off the walls. So I was going to buy acoustic foam for the walls. Before I buy the foam, I wanted to measure the frequency response of ...
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1answer
67 views

Designing a home-made shooting room [closed]

I am planning to build a "shooting room". I explain myself: I want to reuse a half of an old animal shelter to build a small room (3.5 square meters, 1.7-1.8m height) to store all the ...
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1answer
72 views

Unknown polar pattern on bought MXL 990 mic

I just got MXL 990 Heritage Edition, for recording guitar and vocals. However, when opening the box I saw the polar pattern on the box. It's something like this. It doesn't fully resemble a cardioid ...
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62 views

How to do a temporary acoustic treatment of a living room with kitchen extensions, windows and irregular shapes?

Hi all sound design wizards, hope you are keeping safe wherever you are! I am music producer outside my other regular job, and I make instrumentals, record vocals mix and master in my living room. My ...
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31 views

Speakers project outwards

I was wondering if anyone can help me, does anyone know what type of speakers tend to project outwards for a good distance?? Any help would be great, thankyou.
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67 views

Effect of sound waves striking an object

I am trying to understand the effect an acoustic wave has on an object. I have two speakers, one on top of another, and both emitting a Sine wave of 64Hz generated in MATLAB with a sampling rate of ...
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52 views

How works perforated acoustic wood panels?

Perforated acoustic wood panels seem to flourish everywhere in public places nowadays. I saw them installed as room separators, on walls (with or without an air gap), and even on a classroom ceiling. ...
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1answer
60 views

Why not pointing the loudspeaker toward the sky during open-field frequency response measurement?

I'm skimming over documentation relative to loudspeaker frequency response measurement. Regarding open-field/far-field measurements, most authors mention issues with the ground reflection. For ...
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1answer
108 views

How to interpret the analog output of an SPL meter?

I tried to connect the analog output of a Sound Pressure Level Meter to a digital oscilloscope to determine the RT60 of a room. I thought I will somehow have an analog reading proportional to the SPL....
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222 views

How to make realistic instrument sounds digitally from scratch?

I am looking at basic JavaScript Web Audio API examples, such as building simple synthesizers and such, hoping to find something where they create the sound of a drum or the sound of the human voice ...
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2answers
87 views

How much should volume change for an empty room vs one full of bodies?

So tonight I'm doing a film screening. The room is small and will have about 20 people in it. The room is already absorbent, with painted wood on the walls, carpet on the floor, acoustic tile drop ...
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75 views

“Perceptually the ear hears different pitches for soft and loud 100 Hz tone.” - Master Handbook of Acoustics - 5e

After having tried to look for answers as to why the ear hears different pitches for soft and loud 100 Hz tones, here's what I've found : Pitch of the low frequency tone decreases with the increase ...
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107 views

How to Acoustically Treat kitchen-extension of room?

I have a room layout like this. The red panels are acoustic panels placed around the room, and the squiggly surface is gonna be a curtain. There's an extension at the upper part of the room that used ...
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2answers
47 views

best material to absorb Sound

The Loft that I live in used to be a city hall building. The hallways and lofts have very high ceilings and have a horrible echo problems. I am considering hanging some type of sound absorption ...
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1answer
150 views

“Super W” neoprene pads for electronic drum decoupling platform?

I am looking to build a platform for my electronic drums to decouple vibrations (mostly from the kick) to the building structure. The 'tennis ball' platform is a recommended DIY solution often found ...
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1answer
74 views

Shockwaves: loudness or speed?

I got into figuring out decibels, and loudness measurements, and found the number 194dB as the boundary at which a sound starts distoring itself, namely creating vacuums which supposedly turn into ...
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1answer
106 views

Reducing Noise Levels in Dog Shelter Inexpensively

This isn't acoustic design for recording, but certainly related to a number of posts I have seen here. I'm looking to make a dog shelter quieter for their own well-being. It gets very loud around the ...
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1answer
122 views

Acoustics exercise

I have been asked to solve this exercise. An environment of $V=1500$ $m^3$, it is considered a reverberated field acoustic pressure level of $70$ $dB$ when an acoustic source of $80$ $dB$ is ...
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45 views

Directivity index measurement - steps to follow

I am interested in measuring the directivity index of a loudspeaker. I have been looking on the Internet information about the setup, but unfortunately the information I have found so far has to do ...
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2answers
476 views

Question about the Haas Effect

I'm reading an interesting article about incorporating the 'Haas Effect' during the mixing stage of a song but I can't understand the following extract: “The Haas trick adds to the standard panning ...
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1answer
48 views

How does “transcribe!” or guitar tuner work?

Suppose that we have a microphone-recorded note, say played on a guitar, and we want to write a computer program which will detect the note frequency. There are already plenty of such programs. How to ...
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1answer
211 views

Portable anechoic test chamber microphone suggestions

For my senior design project, we're creating an acoustical test chamber that will measure the frequency and the sound pressure of the electrical device that is put in the chamber. The chamber won't be ...
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1answer
50 views

Can I get a recommendation on how big and what type/brand of PA I need?

I am creating a performance space, mostly for music. Presently, it is a 4000sq. foot empty warehouse. We were thinking that the audience could be around 500. Someone said that we should get a ...
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1answer
28 views

Advice on calibrating complex stimuli that vary in amplitude and also decay over time

So I am finding it difficult to calibrate for a particular signal that changes in amplitude over time, and is randomly presented to a listener over a time span. I have attached a picture of the ...
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1answer
59 views

Do I really need to dump tons of sand into the stage i'm building?

I am building a 16x24x3 stage in a 4000 square foot warehouse, to be used principally to showcase music. A local audio guy has told me that I have to fill the wooden framed stage with sand. This ...
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1answer
52 views

Designing a diffuser to direct reflections to side walls

Floyd Toole in Sound Reproduction recommends using a diffuser on the ceiling that should scatter sounds from front loudspeakers that would normally be reflected to the head locations of listeners. He ...
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65 views

Front acoustic absorber placement with in-wall speakers [closed]

I'm building a home theater and plan to use an acoustically transparent screen with in-wall front speakers. Toole's Sound Reproduction book suggests three to four inches thick of acoustic absorber ...
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1answer
167 views

cancel out audio in a recording with convolution, phase inversion

If I am playing audio out of a speaker into a room, and there is a microphone in the room recording all the sounds in the room, can I cancel out the sound produced by the speaker in the recording? I ...
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1answer
124 views

Purely Mechanical Acoustic Frequency Converter

I'm an electrical guy, so I know how to make a frequency converter electrically. Or by using software through resampling, etc. My mechanical understanding of the world is much more lacking. What I'm ...
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2answers
2k views

Reduce bass through wall to neighbour

I like playing loud bass heavy music but I have some problems with a neighbour hearing much of the bass through the wall. I have painted a picture of the situation. The colors are indentified as: ...
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83 views

How to simulate crowd noise with acoustic instruments?

How would I simulate the cheering, applause, and whistles of a crowd using acoustic instruments (and possibly amplification)? Preferably it would be nice to limit it to needing 1–2 musicians to ...
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2answers
6k views

How does a cardboard paper towel roll amplify the sound?

My daughter and I did a project and made this: http://osxdaily.com/2014/07/28/diy-iphone-speakers-paper-towel-roll-plastic-cups/ We hypothesized that the sound was "amplified" because it directed ...
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60 views

What are the Ideal Dimensions for a Reasonably-Sized Studio?

What would be the ideal dimensions; acoustically and logically, to build a free-standing studio? Say you have a small mixing desk(~30''), two average-sized monitor speakers, a computer + screen (the ...
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7answers
9k views

What would be the best “egg-carton” acoustic treatment method?

We are working on treating one of our "studios" at school, which is used for video recordings. The reason behind this project is that it currently sounds like a bathroom. We have thus collected ...
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3answers
3k views

Are styrofoam skyline diffusers efficient as wood?

I'm making my own Skyline Diffusers using a pattern I got from the Internet, and the recommendations were to use a lighter type of wood, such as Pinus. The problem is it's still too heavy, once I'm ...
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1answer
1k views

what is the purpose of the internal volume of a speaker cabinet

I've been reading a bit about speaker design but I haven't been able to find what purpose the internal volume of a speaker cabinet serves. From what I've read, having an internal volume causes extra ...
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2answers
162 views

Simulating Resonant Bodies

Background I am working on synthesized patches using a combination of additive and subtractive methods to create a digital orchestra. The goal is not to recreate orchestral sounds, but rather to ...
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72 views

How can i prevent/reduce bass trapping?

I have to put my monitors in two corners. What can i do to prevent/reduce bass build up issues?
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5k views

Can noise be reduced by 7 decibels with a curtain?

I would like to reduce noise in my room and found a site selling curtains which can reduce noise by 7 decibels. Is this kind of reduction really possible with just a curtain? I wonder if this is not ...
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2answers
136 views

Room Frequency Hum

In my apartment I always had the same problem with D2 at ~146Hz. It feels like a deep hum. The distance between speakers and wall is about 2.38 meters, so f = v / L L = v / f ---> L = 343[m/s] / ...
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1answer
80 views

standing waves in strings

this is for my acoustics and sound lab and I am lost. please help! The length of the smallest string on a piano is about .15 m long and has a frequency of 4186 Hz. The lowest note on a piano has a ...
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3answers
11k views

What is the best shape for passive sound amplification

I'm asking this to make a passive sound amplifiyer. In the web they usually do a HORN shape that looks like exponential function mirrored about 'x' axes. But I wonder is there a better shape for ...
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1answer
1k views

Does the shape of an acoustic/vocal booth matter for maximum isolation?

I am building a vocal booth at home, so I can do voice over work. Now I have some Wood lying around, & will build the booth with wood. I am confused as to, what shape I should build it in? So, ...
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113 views

Why does the internet sound like a sine wave [closed]

I scraped a couple of webpages, then in java converted every letter into a number zero to nine dependent on how far along the alphabet it is. I then turned these into pairs of digits. I imported this ...
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115 views

How can I simulate the microphone response of a bullet's reflected shockwave?

I am doing a project on gunshot acoustics and I need to simulate a realistic microphone response of a supersonic bullet for the same. I have to include the shockwave, the muzzle blast and their ...