Tag Archives: sound

Installation of acoustic foam can lead to death

This type of foam can turn deadly in the event of fire.

I was reminded today of a very somber and deadly episode of club music history. The fire at The Station nightclub in West Warwick, Rhode Island on February 20th, 2003, killed 100 people. While certainly the lack of a sprinkler system contributed to these deaths, equally contributory, or perhaps even more so, was the MISTAKEN NOTION THAT ACOUSTIC FOAM IS A SOUNDPROOFING MATERIAL.

FOAM IS NOT A SOUNDPROOFING MATERIAL.

It does not prevent sound from transmitting. Not even a little bit.

In a misguided attempt to soundproof the club so that the high volume of music inside would not reach the neighbors, the owners of The Station installed a polyurethane substance that they thought was acoustic foam. (A kind of black foam that is commonly referred to as egg-crate style.) Not only does this type of foam NOT even do ANYTHING to reduce sound, it is flammable, and also emits thick, toxic smoke when set on fire. Polyurethane foam is a packing material, not a soundproofing material.

As someone who has studied and done research on materials that affect acoustics, it angers me that most reporting of the incident describe the polyurethane foam on the walls as a “soundproofing material”. This type of material does NOT function as soundproofing.

That night at The Station nightclub, outdoor pyrotechnics were used indoors, and the sparks emitted ignited the polyurethane foam on the walls near the band. If the foam had not been placed on the wall, there is a chance that the structure might not have caught fire. But with the flammable foam on the walls, not only did it ignite, it filled the entire space with deadly, blinding, and asphyxiating smoke in LESS THAN TWO MINUTES. Here is the Fire Safety Institute’s re-creation of what happened that night. Notice that visibility is near-zero at only 1:30 (90 seconds) after ignition:

With only two exits and black smoke filling the venue rapidly, many people were unable to escape and perished. If the polyurethane foam had not been placed on the walls of the nightclub, there may not have been any fatalities as the space might not have filled with smoke so rapidly. A working sprinkler system would have also delayed the onset of the debilitating smoke.

NEVER USE FOAM to try to sound proof or absorb sound. Period.

Rock wool is a completely inert material

In contrast to “acoustic” foam, rock wool (also known as mineral wool) is naturally inert. (Fiberglass insulation is also naturally inert). Rock wool can withstand a blow torch for more than three minutes and will not ignite. Rock wool is found in the U.S. under the trade name Roxul. Watch this video for proof that a blow torch applied directly for three minutes will not ignite Roxul, and after that much heat is directly applied, the wood behind it is barely warm:

Elsewhere on this web site, I explain how you can make 2′ x 4′ broadband acoustic absorbers using Roxul, fabric and furring strips. For even better flame retardation when making Roxul sound absorbers, use flame retardant fabrics.

Use inert Roxul for sound absorption. 

Never use foam. If you want to reduce echoes and sound ambience in a space such as dance studio, recording studio, or music club, use Roxul as the primary material. Also make sure that a sprinkler system is in place and working.

It is tragic, but there have been several similar fires in music clubs in other parts of the world and the U.S. since The Station tragedy. For all readers of this article, please take heed and use the proper materials to ensure the safety of the people who use your building and spaces. Never, ever put “acoustic” foam on the walls, ceiling or floor of an interior space. Only use rock wool (or fiberglass) insulation.

If you currently have acoustic foam or fabric in your interior space, I urge you to remove it as soon as humanly possible. It is a dangerous fire hazard that could result in loss of life in the event of a fire. If you want to absorb sound, use absorbers made of rock wool. They are relatively easy to build and inexpensive to boot.

The Sound of Silence gets an emotional new treatment

disturbed-sound-of-silenceThe classic Simon and Garfunkel song Sound of Silence gets a brand new, emotionally powerful treatment by the band Disturbed. Click the Play button below to hear it, or the Buy button to get the edited 2:25 length version, designed expressly for a lyrical or contemporary competition or recital dance routine. As always, Squirrel Trench Audio delivers seamless and ultra smooth edits.

Get more Squirrel Trench remixes at Legitmix

Protect your hearing at dance competitions

hd-bw-solo_1024x1024We all love the music that our routines are choreographed to, and that’s why dance competitions usually play your music really LOUD. Sound pressure levels of greater than 95 decibels are common in competition venues. You can easily get an approximate measure of the sound pressure level of any environment you are in with a free smartphone app. (I use Decibel Meter-Free for iPhone.)

Most dance teachers and choreographers are unaware that exposure to sound sources at these volumes (94 db or more) for more than 60 minutes consecutively can cause permanent hearing loss (source:National Institute for Occupational Safety and Health (NIOSH)).

That is why I ALWAYS use hearing protection at dance competitions. You can use the cheap, foam type found in pharmacies, but that type tends to muffle the sound, and is therefore not enjoyable to use. I use Ear Peace protectors, which reduce the volume uniformly across all frequencies. The result is that the music sounds just as good as without the ear plugs, but the sound pressure is reduced so that you don’t damage your hearing or leave the competition with a splitting headache. I find that music actually sounds BETTER at competitions or rock concerts with the ear plugs than without, because at super-loud volumes, music actually distorts in your ear drums. Best of all, you can get a pair of HD Ear Peace protectors, with carrying case, for less than $20.

The other great thing about Ear Peace protection is that you can still have conversations with people that are next to you.

Just as you wear sunglasses in bright sunlight situations, consider hearing protection to be the equivalent device for your ears in loud settings. Do yourself a favor and protect your ears the next time you are at dance competition, especially when the solution is quite inexpensive.

Removal of embedded tap sounds

(L to R) Richard Vida and Mark Ledbetter in “The Drowsy Chaperone,” a witty love letter to the madcap musicals of the 1920s with music and lyrics by Lisa Lambert and Greg Morrison and book by Bob Martin and Don McKellar. Directed and choreographed by Casey Nicholaw, “The Drowsy Chaperone” is presented in a limited engagement July 8 - 20, 2008 (opening on July 9), at the Center Theatre Group/Ahmanson Theatre (135 N. Grand Ave. in Los Angeles). For tickets and information, call (213) 628-2772 or go to www.CenterTheatreGroup.org. Photo by Joan Marcus Press contact: CTG Press (213) 972-7376

(L to R) Richard Vida and Mark Ledbetter in “The Drowsy Chaperone. Photo by Joan Marcus Press.

Did you pick out a song that has taps in it, but now you need them removed for competition or any other performance? You are in luck. Squirrel Trench Audio now has the capability to remove embedded tap sounds in music. Click to hear a before and after sample (with taps and with taps removed) from the Drowsy Chaperone. Click here to contact us about removing embedded tap sounds from your audio.

Update: Now available is the original Broadway Cast version of 42nd Street, with taps suppressed:

Get more Squirrel Trench remixes at Legitmix

The reason you don’t want audio from YouTube videos

youtube logo (6)There are many reasons why it’s a bad idea to extract audio from YouTube.

1) It’s illegal.

2) Even pristine audio is somewhat degraded since YouTube uses mp3 encoding of any audio submitted. In many cases, it’s an mp3 of an mp3 of an mp3….. and the audio gets worse every time it’s re-encoded in this manner.

3) But if the above reasons are not enough to convince you it’s a bad idea to extract audio from a YouTube clip, then realize this:  In many cases, what you are listening to on a YouTube clip is the room in which the audio was played. Even if the clip doesn’t have audience noises, like coughing, moving around in seats, and other assorted venue noise, the audio is playing back over a sound system, and being picked up by a microphone, along with all of the reverb, reflections, and echoes of the room in which the music is being played. All of these things combined downgrade the audio, sometimes a little bit, and sometimes to the point of pure garbage. But it’s never as clear as it could be. And once degraded in this way, there is no practical way to restore it, except to go back to the original source. That is why, when creating music edits and remixes for dance teachers, Squirrel Trench Audio always goes back to source audio whenever possible.

If you want GOOD, CLEAN audio, DON’T get it from YouTube!

CD-quality versus mp3-quality – What’s good enough?

A recent comment on a dance facebook group asked for some further explanation on the differences between CD-quality audio (lossless or uncompressed) and mp3-quality (lossy or compressed) audio.

I thought I’d share my explanation on the subject here.

cd.gifBecause mp3s were created when the internet was new, and slow modems were used to connect with it, they have gotten somewhat of a bad rap because early mp3s were at such low bit-rates, that they truly sounded awful. However, as bandwidth has increased rapidly over the years, it’s possible today to get high quality mp3s that are virtually indistinguishable from CD-quality audio.

The audio quality in stores like the iTunes store or Amazon mp3 store are now quite good. Not CD-quality exactly, but on virtually all sound systems that the music will be played on, no one will be able to tell the difference.

I have had the misfortune of working with some really cruddy music sources supplied to me, and once music is degraded (which I will explain more below), it can’t be returned to its original form. It would be like ripping up a costume and then trying to put it back together with duct tape – yuck. So here’s what you REALLY want to watch out for: DO NOT USE MUSIC SAVED FROM A YOUTUBE VIDEO.

CD quality is a very high standard of music quality. Even better forms of digital audio exist, but this is irrelevant for the dance world and dance purposes. Here is a list of format qualities, from fantastic to poor:

  1. CD quality (usually stored as either AIF or WAV format)
  2. m4a/AAC — iTunes store quality, 256k bit rate
  3. mp3 — 256k or higher, variable bit rate – this is nearly as good as iTunes store quality. Most people on most systems won’t hear a difference between this and CD quality
  4. mp3 — 128 k or lower bit rate—- this is where you start to hear what are often called “swirlies” especially in the high frequencies of the music.
  5. The worst possible digital music is music that is saved as an mp3, and then saved as an mp3 again (possibly more than once). This is how audio from YouTube gets to be so bad.

Bottom line: For dance studios, rehearsal, recital, competition – mp3 at 256k or higher variable bit rate, or m4a at 256k or higher bit rate, are going to be fine, with one very important caveat: as long as the song has not been resampled/resaved in mp3 format more than once. And this is precisely why music taken from YouTube ranges so wide and far in quality…. it can be nearly pristine, or it can be severely degraded, depending on how it arrived there.

Just like cassettes in the old days: if you recorded a CD onto cassette, it didn’t sound too bad…. just a small amount of hiss was added. But as soon as you start recording cassette to cassette — you are left with practically nothing but noise after just one or two such transfers. The hiss becomes nearly as loud as the music!

Well, that’s exactly the same thing that is happening with an mp3 to mp3 copy, and this is where compression comes in that you mentioned six comments above (lol). When you save music as an mp3, indeed, you are compressing it, compared to CD-quality which is uncompressed. The mp3 encoding throws away some of the “less important” details of the music in order to save space in the storage of the file. If you take a CD, and save it as a 256k-rate mp3, you can barely even notice any difference. But if you save a 256k-rate mp3 as a 256k-rate mp3, now you are throwing away even more detail. And low-quality YouTube videos have music that is encoded as a 128k-rate mp3. So if a person takes an mp3, and then uploads that as the music of their YouTube video, now you are listening to the same thing in essence as a cassette-to-cassette transfer. If you then save the music track from the YouTube as an mp3 on your computer, and remix or edit it and save the result as an mp3, now you are doing the same thing as a cassette-to-cassette-to-cassette transfer. So if the music sounds awful at that point, well, now you know why.

Here’s an example of audio that sounds terrific on YouTube. Especially if you click the quality setting to 720p HD or higher. (Switching the YouTube video to an HD setting increases the audio quality to the highest available.)

 

Here’s an example of music that has been pretty severely degraded, as a 48k bit rate mp3. This would be similar to saving a 96k-bit rate mp3 more than once:

On the above clip, if you go back to the start of the video, you can hear what it sounds like as a very high quality mp3. Every 30 seconds, it’s played as a lower and lower quality mp3.

If you have any questions about CD-quality, m4a/AAC, or mp3 audio quality, please comment, and I will answer to the best of my ability!

Congratulations to Rhythm Dance Company’s Neon

RhythmDanceCoCongratulations go to Rhythm Dance Company’s senior team tonight; they performed three routines with Squirrel Trench edited or remixed music at Hall of Fame’s Worcester Regional competition held at the DCU Center. Their routine Neon, using a custom Squirrel Trench remix that includes numerous sound effects, was a big winner for the evening, garnering a special Precision Award, scoring a 1st Place Platinum in the category, and winning 4th overall in Senior Large Groups.

Tonight’s performances were:

  • Neon — RDC (Senior Jazz Large Group) — Precision Award, 1st Place Platinum, 4th Overall in Senior Large Groups
  • Werk It — RDC (Senior Hip Hop Large Group) — High Gold
  • Beautiful, Dirty, Rich — RDC (Senior Jazz Trio)

While it is our policy not to share music that is currently being using in competition, in the meantime, you can enjoy the custom remix of Janet Jackson’s Rhythm Nation that Rhythm Dance Company used last year:
https://soundcloud.com/squirreltrench/rhythm-nation-squirrel-trench

Tomorrow’s and Sunday’s performances are scheduled to be live streamed on this web page: http://www.halloffamedance.com/livestream.aspx

The full schedule for the weekend can be found here: http://www.halloffamedance.com/regionals/schedule.aspx?id=442

And a full listing of routines at this weekend’s competition that will be performing with Squirrel Trench audio are listed here.

Break a leg to all of RDC’s and NEDC’s dancers performing tomorrow and Sunday!

Feet Don’t Fail Shaun Now

Shaunessey Tap ChampionI am beaming proud of Shaunessey for her best performance to date… which garned her being awarded the Number One tap routine in her age category, as well as the First Place soloist in the 9-11 age category at this weekend’s StarPower regional competition in Springfield MA. I could not be more proud! Choreography by Lesley Weber. Music by Rhythmic Circus; much love to them for sending me the Minus-Taps mix from their amazingly tapalicious FDFMN song!

Pump Up The Volume

Just finished bringing up the volume of another movie soundtrack song (based on a Broadway show tune) for a dance teacher in Tennessee.

We can raise the volume (without distortion) of any tracks that are playing too quietly compared to commercial releases today. This service is quite different than simply raising the volume in your audio editor of choice, which will invariably cause a harsh kind of distortion called clipping distortion. I’ve actually heard this kind of clipping distortion blasted over competition sound systems. It’s not pretty.

Raising the volume in this manner is most commonly needed for show tunes, movie soundtrack songs, and some older songs. These type of songs actually sound fantastic, because they retain their dynamic range, but in the world of dance competitions, the people responsible for the sound systems expect a certain volume from the CDs they are playing. You can’t rely on them to raise the volume of a soft song because they don’t know if a loud section of music is still to come. (However, if a song is too loud, you can count on them to turn the volume down.)

Bringing a song up to the proper level without distortion is currently being offered for only $19, and if the song is being edited by Squirrel Trench Audio, then this aspect is included in the regular price. What a bargain!

More info about Mastering your Dance Track and Fixing your Music in time for Competitions