Archive for the ‘acoustics’ Category

Introducing the Acoustic Ramp™ Diffuser

Monday, August 1st, 2011

As some of you already know, I invented a new type of number-theoretical diffuser a while ago and I have been working on developing it into a product and filing the necessary patent applications.  It’s called the Acoustic Ramp™ because it is wedge shaped.  The diffuser became my master’s thesis for my degree work at the University of Massachusetts in Lowell in Sound Recording Technology.  The degree that I will earn is called a Master’s of Music in Sound Recording Technology (M.M. S.R.T.) and will hopefully make it easier to get a job that pays the bills!

This past Saturday 7/30/2011 I spent the day running a series of tests on the diffuser and comparing its performance to that of a flat reflector.  Essentially what I am trying to show is how much better the back wall of a control room would be if it had an array of my Acoustic Ramp™ diffusers and wasn’t a flat wall.  When sound hits a flat wall it bounces back, a lot like a rubber ball might bounce.  The problem is that the sound bouncing off the wall interferes with the sound going towards the wall and causes problems like comb filtering, flutter echo and bass buildup. One option for handling the problem is to absorb all of the sound hitting the wall and preventing it from reflecting.  This works, but really changes the sound of the room, deadening the frequency response and creating an unnatural ambiance. The other option is to use diffusion to reflect the sound in many directions and to prevent the sound bouncing back in only one direction.

Testing the Acoustic Ramp

Testing the Acoustic Ramp at U. Mass Lowell's Concert Hall

Testing a diffuser is actually pretty complicated and involved, but in a nutshell the process is as follows:

Shoot an impulse burst of sound at the diffuser and then record what bounces back every 5 degrees in the semi-circle around the diffuser.

The white tape in the picture shows the test points where I placed the microphone. The first test point is at 0 degrees directly underneath the speaker.  This test point simulates what a listener might hear if they were sitting directly in front of the speaker and the sound went past them and hit the back wall of the control room and then bounced back.  A flat wall would reflect a sound very similar to what was coming out of the speaker, essentially an echo that hasn’t been greatly changed. A diffuser should have multiple smaller echoes spread out over time with seriously reduced sound pressure. This is what the 0 Degrees test results look like:

Flat Reflector vs. Acoustic Ramp

Diagram showing the difference between sound reflecting of a flat reflector and sound being diffused by the Acoustic Ramp

As you can see from the diagram, the large reflection in the top response is changed into a series of three smaller reflections  and greatly attenuated (reduced) amplitude when diffused by the Acoustic Ramp.  The reflection is spread across time and diminished greatly in amplitude.

Hurray! It Works!

Studio Construction Photos: Con-Fusion Entertainment

Saturday, June 12th, 2010

Several months ago I was approached by two former students (Evan Schlosser and Robie Rowland) at the New England Institute of Art to help them to design a studio in a rented space in Allston.  They introduced me to their partner Arjun Ray and I started consulting with them.  The space was being converted into rehearsal  spaces and construction was already underway in the space to convert it from an office building into a rehearsal room.  We would convert that into a fully-functional professional studio.

After measuring the space and investigating the existing construction, I came up with a design that would isolate the studio from their 3 neighbors as much as possible and that would provide them with 2 large and functional live rooms and  a good sized and well proportioned control room.  My initial design follows but had to be altered some to address problems such as sprinkler and HVAC locations.

Original Studio Design

The Original Design for Con-Fusion Entertainment's Studio

One of the things that is very nice about the space is the two large windows allowing natural light into the studio’s control room.  I designed all of the spaces to avoid parallel wall to help prevent problems with standing waves and the accumulation of low frequencies in less-than-ideal locations.  The rectangular space is broken up in such a way that the control room gets larger the further away from the mix position.  Both the live rooms have site-lines to the control room as well.  The control room, where the most time will be spent, is the largest room and will allow for comfortable seating for producers, engineers and their clients.

Here are some of the early construction photos.  In the pictures are Arjun Ray, Robie Rowland and Evan Schlosser (The 3 partners of Con-Fusion Entertainment), and Mike, Rick and Robie the Elder.  I tried to create some order to the photos to create a narrative.  At this point, nearly all of the metal studs are in place and drywall is starting to be hung.

Looking at control room from inside the large live room

Looking at control room from inside the large live room

View out of the control room door

View out of the control room door

View into the corner of the control room

View into the corner of the control room

View out the main control room window

View out the main control room window

The wall makes a slight job at the studio entrance

The wall makes a slight job at the studio entrance

Exterior walls filled with 703 fiberglass insulation

Exterior walls filled with 703 fiberglass insulation

Detail of the double wall construction

Detail of the double wall construction

3 Layer studio window in progress

3 Layer studio window in progress

Detail of finished studio window

Detail of finished studio window

Cutting metal studs makes sparks!

Cutting metal studs makes sparks!

Placing the first piece of gypsum board

Placing the first piece of gypsum board (from the left: Evan, Robie and Arjun)

Arjun sealing the top edge of the drywall

Arjun sealing the top edge of the drywall

Signatures of the builders on the first drywall

Signatures of the builders on the first drywall

So those are some of the pictures of the progress.  I would love to hear your thoughts!

Cheaper Alternatives for Audio Cabling?

Tuesday, December 22nd, 2009

The following is a Facebook exchange that I had with a former student outfitting his new studio.  He raises some great questions about what makes a cable compatible with audio.

if i were to put an audio snake through 1 1/4 conduit and i were to use cat5 as a temporary cheap(free) way to do this would it work for 16 channels?

I know it will fit in the conduit.. at least thats what the electrician told me.
I am more interested in how well cat5 will work as a temporary audio cable

CAT5 unfortunately will not work as audio cable unless you convert all the audio to digital first and then shoot it down the line. This would be REALLY expensive. CAT5 isn’t shielded, though the “twisted pair” nature of it does help a little. CAT5 has 4 pairs of very thin solid core wire, so that you would only get you 4 channels, even if there was a shield.

Your best cheap option for 16 channels is to buy 16 channel snake cable and solder the ends without the breakout box. Redco does sometimes have used snakes for sale.
Do you need all 16 channels? What else is in the conduit? If there’s any power there don’t run any audio into it!

I like Clark Wire’s cable because of the color coding and a very convenient drain wire

Do you mind if I post your question anonymously on my blog?

Go right ahead and put it on your blog. I figured the lack of shield would destroy me. I am just in a situation where i can get way more than a hundred feet of it for free and was wishing it would work. i only need to go about 50-60ft so i would have done 4+ runs of it.

The conduit is going to be along the baseboard and the power is going to be ran through the ceiling and come down where needed about 12-18inches up the wall.

My parents have a mid sized barn(closer to small i guess) that they currently rent out. The renters have told my parents they will no longer need it after January. I was hoping to get a little project space for when i am not busy over the summer. i might “steal” some of the “broken” dmx/XLR from work and see what i can do with that before buying stuff i can’t afford ha ha.

on a side note…
Will 5 wire DMX work if i just don’t use a wire?

DMX Cable has higher impedance than audio cable because it’s for data. DMX is around 110 Ohms while audio cable is around 70 Ohms. I also think DMX cable has thicker shielding. You could probably use DMX cable for digital connections like AES-EBU which also uses an XLR connector.

It’s possible that you could send audio on a DMX cable but you might get signal loss because of the higher impedance. I wouldn’t risk it personally. I would see if you could find a used snake somewhere and fix what needs to be fixed.  Sometimes companies have short lengths of cable that they will sell for a discount.

Good luck!

Please let me know if anyone finds out some new cheaper ways of doing our work!

Audio Quality: How to Build a Listening Room (Part 1)

Saturday, October 24th, 2009

At this year’s AES meeting in New York City, the AES Educators took up the topic of how to teach our students to recognize and strive for the highest quality audio possible.  In order for us to teach  techniques to attain the highest audio quality,  students must have access to good listening environments. The traditional concept behind building a great listening room is to build a room which is essentially a studio control room.  Unfortunately this is extremely expensive, usually requires an acoustician and often an architect and is way out of the price range of most learning institutions.   What is needed is a clear set of guidelines to convert existing horrible sounding rooms into adequate critical listening spaces as cheaply as possible.

Gone are the days of the listening party, where people would come together and listen quietly to music together.  But the listening party teaches us a lot about what a listening room should be like.  Here are some ideals that we should strive for in the listening room:

  1. As Quiet as Possible
  2. As Symmetrical as Possible
  3. Use DIY Acoustic Treatment to Control Problems
  4. The Best Loudspeakers that Can Be Afforded in Good Positions
  5. Use the Creation of a Listening Room to Educate the Students

I teach Audio Technology 2 at the New England Institute of Art in a concrete box, which arguably the worst possible environment to do critical listening in.  If memory serves the dimensions are about 17 x 19 feet with 10 foot ceilings with a drop ceiling at about 8 feet.  I will try to use this room as the guinea pig room to talk about these issues. With any luck, I will get permission and a small budget to improve the room’s acoustics so that it becomes a better environment both for listening and for teaching.

– Hendrik

In the spirit of using my blog as a great way of complaining about the general state of the world I offer the following whine:

Today we have a great many adversaries to high quality audio, some of which I have outlined below:

  1. The dominant listening device is an iPod with Apple-made earbuds. (eew!)
  2. Most modern music productions are over-compressed so that they sound as loud as the other over-compressed recordings. (grody!) This is usually referred to as The Loudness Wars. (Also check out: The Death of High Fidelity)
  3. The second most dominant listening device is the car. (very noisy!)
  4. The third most dominant listening device is the craptop computer. (Noooooo!!!!)

What books do I need for Survey of Music Technology at UML?

Friday, January 23rd, 2009

As many of you already know, I am now teaching at two colleges: University of Massachusetts Lowell and the New England Institute of Art.  At both schools I teach in the Audio Production departments, but at UML, it is called SRT or Sound Recording Technology. I can recommend both of the text books.  They have different perspectives and both are well established texts in the field.

The first book that is required reading for UML’s  class 78.305 “Survey of Music Technology” is Experiencing Music Technology by David Williams and Peter Webster.  The book is quite expensive in stores, but is a little cheaper at Amazon as usual. A new edition of the book has just become available to update the content with internet technologies, contro surfaces and other innovations from the last 10 years.

Experiencing Music Technology Book

Experiencing Music Technology

The second book is also expensive unfortunately. Audio in Mediais in its 8th edition and is one of the most updated books on the subject. This text covers everything from acoustics to post-production. It’s fantastic overview of music technology from mics and loudspeakers to control surfaces and signal processors.

Audio in Media Book

Audio in Media

DIY: A Jecklin Disk for Stereo Recording with Omni’s

Tuesday, May 20th, 2008

What’s a Jecklin Disk?
A Jecklin Disk is a device that helps to record the most natural sounding stereo image that I have been able to achieve. It is a 12 inch circular disk with acoustically absorptive foam on both sides. Omni-directional microphones are mounted on both sides of the disk. The foam acts much the way your head works to block high frequency sounds from being picked up by both microphones equally. The sound is delayed as it tries to get around the disk and high frequency sounds are absorbed.

For instance, if there’s a sound coming from your left side, sound travels first to your left ear and then to your right ear. The delay that occurs between the left and the right helps us to determine directionality of the sound source. Additionally the sound gets partially absorbed by your head. So you get more high end sound on the side of your head that is closest to the sound source. The Jecklin Disk emulates this. Our friends at Mercenary Audio have a great version of the original article by Jürg Jecklin. ( If you aren’t interested in making a disk yourself, you can easily order a really nice commercial model at Mercenary!

This is what a Jecklin Disk looks like in use with a pair of Earthworks TC25 omni’s:

Now that you know that you want one, but you don’t have $260 here’s how to put one together:

First step is to get out your trusty compass and set it for a 6″ diameter, which will create a 12″ circle. Compasses are really great for working with measurements and drawing circles in specific distances from the edge of a flat surface.

Stick the point of the compass as close as possible to the corner of a piece of 3/8″ nice-on-both-sides plywood and mark out 6″ on both the edges of the plywood. You can just draw an arc across the whole board if you want. I put the lines on the plywood already so you can see what I’m doing.

Next, you stick the point of the compass at the edge of the board where you drew the arc. This point is 6″ away from the corner. Draw an arc on the board where the center of your disk will be. Now move the point of the compass to the other point where your first arc intersected with the edge of the board and draw another arc where the center of the disc will be. Where these two arcs intersects is the center of your disk.

Now you can draw out your 12″ circle by pointing the compass in the center and making a complete circle.

Now it’s time for POWER TOOLS! Be sure to use hearing protection and eye protection. You never get you hearing back when it’s damaged. I prefer to use a saber saw (also called a Jig Saw) for cutting arcs and circles. You want to use a smallish blade with small teeth designed to cut wood, not metal.

Carefully cut the circle out of the plywood. Don’t worry about small imperfections in the cut because you will be sanding the edges smooth.

Now that you’ve cut the circle out of the plywood, take the rest of the plywood over to the table saw. We’re going to cut out 5 of squares of plywood to make the base of the Jecklin disk. These will all get sandwiched together to make the base that the mic stand threaded flange will attach to. Rip the first rectangle from the edge of the cut circle so that the disc will nestle perfectly in the base.

After cutting out all the little rectangles, you can see the odd one with the arc cut into it. This will be the middle piece of the sandwich.

Get your clamps, wood glue and blocks ready to glue together and clamp.

Glue is art. The glue is a abstract representation of the emptiness of the skulls of our nations leaders. After you get all the pieces together, clamp them after making sure all the pieces line up as smoothly as possible.

Go ahead and put the base aside to dry (give it at least an hour or so). Now go to the drill press to putting the mounting holes through the disc. This will be where you’ll mount two microphone stand flanges on either side of the disc. My drill press has lasers! Jealous?

After you get the disk drilled out and the base is dry. Go ahead and glue the disk into the slot in the base that you left with the arc cut out. Notice the two mic flanges on the table saw to the right of the disk. After the glue dries, you’re going to need to thoroughly sand the entire surface of the disc and the edges of the base as smooth as possible.

Fit self-sticking foam to the disc in preparation to attach it permanently.

After you have your foam cut correctly, you can go ahead and seal the disk with a few coats of Polycrylic, a latex version of polyurethane. Polycrylic is great for furniture that isn’t going to be walked on, but it really sucks for floors because its just not hard enough.

Notice that the wood grain is coming out more with the layers of clear finish.

After the Polycrylic dries, go ahead and attach the self-sticking foam to the disc and trim all the excess off with an hobby knife.

The last step is to bolt on the mic flanges through the disk. You will mount your mic clips onto the flanges.

Here’s a close-up of the base of the Jecklin Disk.

Now add a couple of omni’s and you’re good to go. Two omni’s on a Jecklin Disk, a few feet in front of a drum set, make for a wonderfully natural drum sound. A great inexpensive omni mic is the Audix TR-40, which sounds wonderful and almost as good as mics costing 5 times as much!

DIY: Building Acoustic Treatment for a Piano Room

Wednesday, April 9th, 2008

The following is a step-by-step explanation about how to build acoustic treatments that are easy, economical and quite beautiful.

Why We Needed the Treatment in the First Place
At our wedding, my wife and I were given by our friends and family contributions toward buying a Yamaha U-3 upright acoustic piano. We fell in love with one at East Cambridge Piano (which is actually in Somerville now!). A couple of months after the wedding when the dust had settled we paid for the piano and had it delivered to our home. We were both so excited about it coming, but when it got to its new home the instrument sounded really different. The tone was still very good, but the rooms reverberations made the piano really loud and at times unpleasant sounding. An acoustic guitar could never play with the piano because the piano would take over the sound in the room.

Laura, my wife, plays piano and performs in a Latin American fusion group called Son del Sur (Song of the South). The group has a minimum of 4 women singers, 1 male singer, 2 percussionists, 2 guitars and assorted other musical snacks. To be frank, they sounded absolutely awful in the room. The sounds were all competing with each other: the voices covered the guitars, the percussion had no where to go but louder and louder. The musicians couldn’t hear themselves or the people they were playing with. Something needed to be done:

This is what the room looked like when we started:

As you can see from the photos, the room is bare except for the piano and the table. The bay window breaks up the parallel walls from front to back and the closet door and the bed room door create a nice diffusion to break up the side walls. The natural reverb is really quite lovely and for a solo instrument (like a violin, vocal or acoustic guitar) the room sounds great. Unfortunately, anything louder than that and the ambiance turns in a noisy, brassy screech.

Based on the shape of the room I calculated that the most important walls to treat were largest flat wall (opposite bottom photo) and the wall above the piano. The goal would be to start with a minimal acoustic treatment and add more later if necessary. The plan was to build 4 panels, 4 inches thick in frames 2 feet by 4 feet. The acoustic absorptive material is Owens & Corning 703 Rigid Fiberglass Insulation. We would then stretch fabric over the frame and the fiberglass to keep the fiberglass from getting in the air and then getting into people.

Here’s how we did it:

The following 2 photos show the wood stock and 703 Fiberglass that we used to build the acoustic panels. The wood is 3/4″ furniture grade plywood from Home Depot which was $26 for a 4′ x 8′ sheet. We ripped in into 4″ strips with my trusty Makita portable table saw. (very dangerous…don’t try this at home kids…we’re professionals…) The 703 stock is 2″ thick 2′ x 4 panels. I bought them at Kamco in Woburn, MA for $80 for 12 sheets or 83 cents per square foot. This is about HALF the price that you pay when you buy it on the web. Do yourself a favor and find a good insulation supply house! (Eat you heart out Auralex! ($3.75/sq. ft)

Here we are setting up our first 45 degree cut for where the corners of the frame are joined together.

Ty Smith cutting the 45’s with earplugs in but without a dust mask:

Ty with earplugs AND a dust mask…Sawdust makes a bad lunch.

Squirting glue on the joint:

Spreading glue with the glue spreader that mother earth gave us:

Using 90 degree corner clamps to hold the corner while we nail the frame together and wait for the glue to dry:

More clamping:

Popping in a couple of 8 Penny finishing nails for over kill at the joint:

Waiting for the glue to dry:

This is what a frame looks like after it has been assembled:

Ty stacking the frames so they can dry completely:

A Jecklin Disk was used to record the ambiance of the room before the treatment went up. Look for the actual before and after sound files in a later post…

Recording the bare room:

Assembling the acoustic panels on the table. The 703 fiberglass was pressure fit into the frames and the material was held in place with friction:

These are some panels that have been assembled but the material hasn’t yet been glued down:

The first panel has been hung, one glued panel is drying against the wall and another panel is being glued closed:

Three panels mounted on the wall in their final locations:

An additional panel mounted above the piano to absorb reflections from the top of the piano:

I hope that this post has helps some people control the acoustic in their music spaces. Please feel free to post links to your own DIY acoustic treatment projects.


Forensic Acoustics: the Gary Zerola trial

Monday, March 31st, 2008

Earlier this month I was hired by Janice Bassil, of Carney & Bassil, P.C. , to conduct a series of acoustic tests to determine audibility and intelligibility between different rooms in a Beacon Hill apartment in Boston.

The apartment in question is on both the first and basement floors of a multi-unit building. The first set of requested tests was to determine if a woman’s voice in the basement bedroom could be heard by witnesses in the living room immediately above the bedroom. The bedroom was accessed by a spiral staircase in the corner of the living room. To implement the test I would need to play a woman’s speech through a loudspeaker in the bedroom at conversational level and then measure the level of the audio in the living room above.

I brought a XP-based laptop with Sonar 6.2 installed on it, a MOTU Traveler, a pair of calibrated Earthworks TC25 omni-directional small diaphragm condenser microphones, and 2 SPL meters. The first step was to calibrate the speaker to a “conversational” level (about 60-70 dB). For my source of a woman’s voice, I chose to use a woman reading Shakespeare’s “Romeo and Juliet,” played back via the D.A.W. (Sonar in this case). I lowered the output of the voice until my SPL meter averaged between 60 and 70 SPL. At this point I placed 1 TC25 about 1 meter from the speaker, off-axis and then placed its twin in the center of the living room upstairs. A partner would measure SPL in the living room while I ran the D.A.W. and measured SPL in the bedroom.
The Traveler uses digital controllers for its on-board preamps, so I was able to set both preamps to precisely the same boost in gain of 20 dB. To calibrate the whole system and to create a baseline for our further tests, I ran a series of simple sine wave tests at different frequencies and different levels. This would help to determine which frequencies in particular traveled better or worse in this acoustic space. My partner and I took SPL readings for each tone which we recorded to compare later the peak and RMS levels in the D.A.W.

Having completed our baseline tests, we began to record the voice, take readings, then decrease the output levels and repeat. The goal was to determine at what point the voice was now longer intelligible and then no longer audible. Signal to noise ratios in the living room where higher do to increased exposure to street noise due to much larger windows compared to much smaller windows in the bedroom.

After completing two additional series of similar tests, we packed up the gear and I headed home to the studio to evaluate the audio we recorded and enter the data that we compiled. I entered the data into an Excel spreadsheet and organized the audio data so that each audio recording could be listened to separately, first the audio from the bedroom and then the audio from the living room. Doing this made it very clear how much the audio dropped in level as the sound moved from the bedroom’s acoustic space into the living room’s acoustic space.

The most powerful example was to recreate the acoustic experience of the test. Using the SPL meter, I matched the reading that I took for each part of the test to the output of the speaker that I was playing the test back on. For instance, if I had taken a reading of the voice reading at 65 SPL at 1 meter from the speaker, I would set the speaker to play back the test at 65 SPL. Then I played back both the recording from the bedroom and then the recording from the living room showing the same reduction in energy that was present at the test site.

After presenting my findings to my clients, I was asked to appear on March 24th at Suffolk County Superior Court to testify in the rape trial of Gary Zerola. I answered a series of questions from both the defense and prosecution and played the audio demo of my tests as I explained previously.

Designing a Teaching Studio for the Northshore Recovery High School

Monday, September 24th, 2007

Almost a year ago I was introduced to Michelle Lipinski, the director for the Northshore Recovery High School. One of the folks working at the school knew Woody Giessmann from Right Turn and Woody recommended that I might be a good guy for the job of designing and building a recording studio for the school. I have built 3 studios for myself and helped put together a bunch of others. I have done a lot of remodeling and design work, so recording studio construction really floats my boat!

Michelle won a grant to build the studio and she had several rooms at the school that she could convert into studio spaces. My task was to design a space that didn’t break any of the many rules for altering the building, that worked as a teaching studio, and had some security to keep the neighbor-hoods from wanting to break in and hurt themselves with police batons. There were a bunch of choices of spaces, but we settled on the existing computer lab for both security and ease-of-conversion reasons. This is what the space looked like last Fall:

Some of the things that are really nice about this space are that there are already rooms attached that are separated by glass, so making isolation rooms will be much easier. The room has tall ceilings and there a lot of space to move around in. The bank of windows makes for a lot of natural light which is (for me at least) MUCH more conducive to creativity than sitting under the flicker and buzz of the banks of fluorescents.

Due to the fact that the school is part of a public school system, I had to put together 3 different quotes from 3 different vendors for all of the equipment. As it turns out, this is much harder than it should be. The first problem is that not all vendors stock the same equipment, so you can’t really compare the price of one piece of gear to another. I found that I would have to price out similar pieces of equipment from different manufacturers, or find pricing from different vendors all together.

I got quotes from Guitar Center Pro Audio (Chaz from the Boston store), from Sweetwater, from Parson’s Audio and some pricing from Full Compass. The only vendor that could get all of the equipment that I wanted was Guitar Center, but initially they didn’t have the best price for everything (just most things.) Fortunately, they matched all of the prices and Chaz really took care of us. Guitar Center turned out to be the best as far as price went and Chaz is quite knowledgeable. Unfortunately he is drastically over worked and super busy. There aren’t a ton of folks at Guitar Center that know very much, so I found that I pretty much had to work with Chaz or the other managers of the departments.

I decided to go with a studio based around a Dell XPS super-swoopy computer and Cakewalk’s Sonar. The school’s tech consultant already had a good relationship with Dell and he was able to take care of ordering the computer and peripherals. The other equipment, software and hardware was my responsibility. The main components of the studio were as follows:

  1. M-Audio’s Delta 1010: a PCI based audio interface with great stable drivers and solid workmanship. I used these in my personal studio for years and I have always been really happy with the drivers and the stability of the unit. It works with all the software platforms out their and with Pro Tools.
  2. Mackie Onyx 1640. This is a premium version of the 1604 VLZ. It has much nicer pre-amps and EQ, longer faders and a much better feel. Another advantage is that all of the channels have direct-out via D-Sub to TRS fans.
  3. Mackie HR-824 Studio Monitors. These are my favorite monitors for under $2000. They sound great and are flexible for set-ups in many locations. They have built in power amps tailored perfectly for the speakers. The imaging is great and they have plenty of low-end for modern production.
  4. dbx 1066’s. My favorite mid-price compressors. Very flexible and transparent, the 1066 has a sidechain, expander and limiter built in. They work great as dual mono and in stereo link mode. I have been really happy with their performance and they are very common in lots of studios.
  5. Sonar Producer 6.2. I believe that Sonar is the best DAW available today. It has a suite of great sounding plug-ins, many software synths and drum modules, full looping tools, the best MIDI implementation around and fully customizable workspace.
  6. FL Studio Producer (Fruity Loops). Many of my fellow pro’s think that this software is a toy. It’s actually much more powerful than Reason and it works with VST and DirectX plug-ins. It has an amazing built in Vocoder and tons of capability for mixing and sound design. It can run as a Rewired app inside of Sonar. It is also one of the easiest software applications to learn and get started with that’s out there. I feel like it’s an ideal tool for teaching audio, sound design and mixing.
  7. Sony’s Sound Forge and CD Architect. This is the easiest to use audio editor out there and they actual have tech support. Steinberger’s WaveLab is great unless anything goes wrong and then you are completely out of luck. I gave up on WaveLab after spening about $600 for a full version. I didn’t upgrade because they completely suck on customer support. Sound Forge with CD Architect costs about HALF what WaveLab cost by itself. I did like Sonic Foundry a lot before Sony bought them, but they haven’t seemed to go down the tubes! Hurrah!
  8. Rode NT-2A, NT-5 Matched pair. Rode is an Australian mic company that I have worked with since 1997 when I bought the original NT-2. These are great mics and they are priced very competitively. These guys are flexible and sound great. The NT-2A will be our main vocal microphone and we will use the NT-5 both with omni and cardioid capsules.
  9. Sennheiser MD-421, Electro Voice RE-20, AKG D-112, Shure SM58, Shure SM57. These are THE mics to have to start a studio. Every single one of these is a classic.

The “Shark Fin” Cabinet Construction

Sunday, September 23rd, 2007

I have finished building the first cabinet prototype of the Shark Fin Portable PA. I used 1/2″ plywood for the shell of the cabinet and 2x stock wood ripped into specific shapes and angles for the frame of the cabinet. Elmer’s Carpenter’s glue was the main glue for the construction. I used GE Silicone II 100% Silicone Window & Door Caulking to seal the cabinet.

This the bottom panel or base of the cabinet. The wood frame was ripped from scrap 2×10’s that I had lying around the basement. I used the Google Sketchup tools to determine the proper angles to cut all of the bracing pieces. All of the bracing was glued to the base and not screwed so there would be no screw heads on the bottom of the shell to cause the cabinet to be off-balance or wobbly.

Each bracing piece was glued and clamped separately. Elmer’s sets quickly (30 mins), so it didn’t take very long to get all the base pieces attached.

I used 90 degree angle clamps to hold the sides of the cabinet in place to make sure that I cut all of the angles correctly. The angle clamps are essential in getting the pieces together plumb and square. The two side pieces are being glued in place and front panel is locked in to make sure that the side pieces are in the right place.

This is the front view of the panels’ alignment being verified.

Now that the side panels have been glued in place, I am gluing in the bracing pieces for the bottom front panel. Notice that the cross bracing has already been installed to hold the side panels apart. After the side panels were glued in I used self drilling pan-head screws to screw the panels onto the frame for additional strength.

This is the view of the previous photo from the inside of the cabinet.

The front panel has been glued and screwed down. The extension clamps were used to pull the sides of the cabinet into square before the panel was screwed down.

The view from the front after the front top panel has been added to the cab.

Another of the same.

Clamping and gluing the top panel to the frame. No screws will be used here so that there will be no screw heads to interfere with the PA’s controls.

This is the caulking I used to seal the inside of the cabinet. This small tube is much easier to work with inside the box. I never would have been able to get a full-size caulk gun in there.

Detail of the sealed seams inside the cabinet.

Detail of the + and – leads attached to one of the Galaxy Audio full-range speakers. Note that I used colored tape to clearly show the polarity of the speaker leads. I used a battery to determine the polarity of the actual speaker because they weren’t clearly marked.

The two audience facing speakers. The bottom larger speaker is the Selenium woofer.

A full view of the cabinet with the leads and the speakers installed.

This is a detail of the panel where the speaker jacks are installed. The top jack feeds the “monitor” speaker and the bottom jack feeds the bottom two “audience” speakers. The top jack is 8 Ω and the bottom with two speakers is 4 Ω. I used on outdoor blank switch cover plate for the jack panel. These cost about a dollar, are very easy to drill and come with a foam rubber gasket.

Full length view from the back before the cabinet is closed.

Front view of the closed cabinet ready for frequency response testing.

The next steps after testing are determining if a tuned port will be needed to extend the low frequency response of the cabinet, adding the amplifier and battery power to the cabinet, and adding mixer inputs and controls.