Archive for the ‘education’ Category

DIY Audio Mixing Circuits

Saturday, November 24th, 2012

For a while now I have been interested in summing in the analog as opposed to the digital domain and I built a 16 channel summing mixer with Daking-style amplifiers. I haven’t been very happy with the usability of summing mixers without linear faders and pan controls. It just doesn’t feel right. If you’re mixing with rotary knobs, you can only turn two knobs at once, but when you mix with faders you can do at least 8 at a time.

I basically started doing some research about the kinds of circuits that I need to build and I wanted to post links to the stuff that I found to be the most helpful.

Simple Mixer Schematics from All Electric Kitchen: http://www.all-electric.com/schematic/simp_mix.htm

Slightly more complex mixer circuits (Pre’s, EQ’s, Line Drivers):  http://www.all-electric.com/b&c.html

Elliott Sound Products (ESP) Article on Audio Mixing: http://sound.westhost.com/articles/audio-mixing.htm

I will add information as I read more!

Classic Gear: Distressor

Wednesday, October 27th, 2010

By Carlton Meriwether (from the New England Institute of Art AKA AI New England)

Distressor EL8-X

Distressor EL8-X

Distressor EL8-X

The Distressor EL8-X is a mono digital compressor/ limiter produced by Empirical Labs. A highly adaptable machine they’re considered one of the industry standards for compression and distortion. They have a multitude of compression ratios ranging from 1:1 to 20:1 and a Nuke setting for brick wall limiting. Two types of distortion can be applied focusing on 2nd or 3rd harmonics.  Time based features like attack and release are calibrated to keep consistency between machines when stereo linking.

The Distressor was built with not only modern compression but with vintage emulation in mind. The Distressor has a soft parabolic knee when set to ratios less than 6:1 giving a more natural sound to compression. Setting the unit to 6:1 or greater applies a more sharp vintage knee to simulate tube, FET, or  optical compressor machines from the past. There are specific settings listed by the manufacturer to emulate the LA-2A, 3A, 4A; the dbx160; the Fairchild IGFET and 670.

With a frequency range of 2Hz to 160kHz and a 110dB dynamic range the Distressor is a complete all around compressor. With an MSRP of $3000 for a pair ($2295 through dealers like SweetWater) the Distressor is a reasonably affordable replacement for multiple vintage compressor/limiter rack modules. An over all well built machine utilizing all metal film and Roeder resistors, the craftsmanship is well above average in American made electronics. The hand connected input and output ports allow for consumer changing of the “hot” pin in the xlr connectors to match any gear already in use and the A/C power source can run on 110 and 220 volt inputs giving the Distressor superior compatibility on a global scale.

Sources:

http://www.empiricallabs.com/distdes.html

http://www.empiricallabs.com/index2.html

http://www.wikirecording.org/Distressor_Compressor

http://www.wavedistribution.com/distressor.htm

http://www.empiricallabs.com/distman.html#DRatios

Classic Gear: dbx 160

Monday, October 25th, 2010

Written by Joe Cenedella (New England Institute of Art AKA A.I. New England)

dbx 160 (1976) Designed by David Blackmer, using early Overeasy circuit and RMS detection

The dbx 160 was introduced in 1976 as a professional quality compressor/limiter.  The brainchild of David E. Blackmer (founder of dbx) it quickly became a must have for studio engineers of the time.  Besides being one of the earliest compressors, the dbx 160 introduced to the market features that allowed for a much smoother and more natural sounding compression.  The 160 uses voltage controlled amplifiers (VCAs) which adjust gain settings to fluctuate with the voltage creating smooth and natural sounding compression that closely simulates how the human ear interprets sound. Along with the VCA the dbx 160 introduced true RMS detection paired with feed forward gain reduction. This allows the model to achieve an infinite compression ratio (120:1) without excessive gain levels, and without excessive distortion, which causes oscillation in the feedback loop. All models of compressors at the time the dbx 160 was introduced gave the user some control over compression in the form of preset ratios (10:1, 20:1). (source) this is where the VCA’s come in allowing the attack and release to fluctuate with the input signals envelope. This allowed for more of a set it and forget it approach instead of constantly adjusting the ratio throughout a performance.

The Features:

Auto detected/attenuated 40dB for ground loop hum

Introduced “over-easy” compression, or soft knee compression

Adjustable threshold 10mV-3V

LEDs for input level, output level, or gain

First to have fully adjustable compression up to 120:1

RMS detection, VCAs, and Feed Forward gain reduction

VU origin adjustable 20dB (+/- 10dB input)

Mono inputs, two required for stereo tracking

Output level of +/- 26dB Hi-Z, +/-24dB Lo-Z

Cost New: $300 in 1976

Cost Now: pair sells on ebay for $1600

Link to user manual: http://mixonline.com/online_extras/dbx_160.pdf

Official dbx Pro Audio Info: http://www.dbxpro.com/vintage_download.php?product=160

Other Sources:

http://mixonline.com/TECnology-Hall-of-Fame/1976_dbx_160VU_complimiter/index.html

http://www.barryrudolph.com/mix/comp.html

http://en.wikipedia.org/wiki/Variable-gain_amplifier

http://en.wikipedia.org/wiki/Dbx,_Inc.

Before You Come to the Studio to Record an Album…

Sunday, August 2nd, 2009

Many potential clients ask me the same questions before they come into the studio to work on their albums or EPs:

What should I do to prepare myself to make a great recording?

Should I record a demo myself first?

I almost always answer the questions with more questions:

1.  Why do you want to make a recording?

Is it to get gigs?  Sell at gigs?  Try to get licensing for TV or movies? Is it to finally hear the music the way that you hear it in your head? Is it to document your songs accurately to the way you play them or is it to fully realize the full arrangements with drum, bass, strings, urdu?

2.  Who is the audience of the recording?

Record label executives  or your friends and fans?  Are you the audience for your own music or are you trying to sell this stuff?  Are you planning on giving it away as a promotional tool to help build your following?

3.  Are you ready to record in a studio now or do you want to demo the songs to figure out how they should be arranged and performed?

Usually demoing the songs yourself will help you figure out what you haven’t practiced enough, and force you to think about the dynamics and the tempos and the form in a way that you haven’t already.  I always want artists to know the tempos of the songs before they come to the studio.  If they can bring lyric sheet with chord changes that also really helpful as well.

If you have a way to record yourself, I would always do at least some recording yourself to help you figure out what you are trying to do.  The recording equipment can be very simple, like GarageBand, a 4-Track or 8-Track cassette or digital recorder, or something a little more sophisticated like a full-blown DAW like Sonar, Logic,  Cubase or ProTools.

After you have had a chance to record simple versions of the tunes with piano or guitar and voice, then you can think about adding other instruments in a much more concrete way.  Some music might start with a drum pattern or loop and build from there.

After you you have done all this pre-production, it will be time to start talking to a good producer or engineer to help really get the recording process planned and started.  As a engineer, it’s much easier for me to do my job when the music is more fully formed before I start my work.  As a producer, I like to be involved in the music process as early as possible so I can help to shape the form, dynamics and feel of the song while the song writing is in process.

How to Become a Hip Hop Producer

Saturday, July 4th, 2009

Their is difference between someone who makes beats – meaning composing and performing (or programming) original instrumental music, someone who is really a producer, and a recording engineer that specializes in hip hop tracking and production.

The fastest way to learn to beat making is to make beats with whatever you have available. I have worked with a couple of heads who were complete geniuses with the Playstation software from MTV. Their music was simply amazing. Software that is highly under-rated is FL Studio or FruityLoops. The step sequencer is the easiest way to make music quickly. Read the manual! Watch videos online.  Start working with as many other beat makers that you can find on the net, in your home town. For me, competition made me write stuff that was much better than working by myself in a vacuum. The three big instruments to learn would be keys, drums, and bass. You did not need to work in a studio to do this kind of work. You need a computer, a decent audio interface (Not an M-Box), and a couple of nice monitors. If money is a factor, don’t get a Mac. You get a lot more computer in the PC world and there’s tons of software available.

A real producer puts the whole show together. They hire everyone, often write songs with the artists, choose the studio to work in, find live musicians to fill out the sound. Sometimes that means doing everything yourself. A lot of the time the producer FUNDS the project and gets the biggest share of the profit (if any).  A producer is a big picture person usually with an excellent understanding of the psychology of creative people, motivation, fear, competition and excellence. This is something that comes with lots of experience, a strong musical background, charisma and usually fame or money.

An engineer deals with the tiniest details of tracking and mixing. Moving a mic a half inch, rotating a mic off axis, how to attenuate the peaks of the kick to get it to sound bigger, without making it wimpy. Attack and Release time minutia for compressing drums, bass and vocals. How the sound stage can be used to the best advantage, how to either avoid masking or use it to create new timbres. You need to learn this either in a studio as an apprentice, in a good audio school that has great facilities (I teach at New England Institute of Art in Boston and at U. Mass Lowell both have great facilities) and then leverage that into getting good internships.

Sometimes there are people who really are all three. Sometimes you will find yourself in one role or the other depending on who you’re working with.

The best job to get to learn audio engineering is working for live sound companies as a grunt. You will carry the bass bins, mic stands and a 43 foot console. But you will get to watch the FOH and monitor guys throw down. Live is good because it forces you to learn to do things quickly and it puts you around dozens of musicians every weekend. Not wanting to be embarassed is a very powerful way to learn.  You are always on stage being watched from the time you load in, to the time you strike the stage.

(posted to GearSlutz 7-4-09)

For NEIA Students: Cheap Alesis HD24 Caddy Options

Saturday, January 24th, 2009
Alesis HD24 Hard Drive Caddy

Alesis HD24 Hard Drive Caddy

Most of my audio students at the NEIA (the New England Institute of Art) want to know the cheapest way to get an Alesis HD24 caddy for their Recording 1 and Recording 2 classes. Unfortunately you pay for convenience when you shop at the school store, but you can get it cheaper off the web. As per usual you can find the best deal at Amazon right here. At the time of this post, Amazon has it listed at $22.95 via Musician’s Friend. After you order this, you will also need a IDE/PATA drive to stick in it. You won’t need a very big disk for your classes at the Art Institute. Anything more than 80 GB will be fine.

Current Great Deal on Amazon:
Seagate Barracuda 7200.10 – Hard drive – 160 GB – internal – 3.5 (currently $47.41)

Make sure to NOT buy anything that says SATA on it, or anything that says 2.5″.  What you want is a 3.5″ 7200 RPM (Revolutions Per Minute) (IDE or PATA or Ultra ATA) Hard Drive.  You can get one that is boxed or OEM, which is cheaper. Here’s a few inexpensive options:

If you are mobile or adventurous you can always go to Microcenter in Cambridge on Memorial Drive to buy your hard drive.  They have great deals and a convenient order-on-the-web and then pick-up at store feature. I really hope that this helps!

HDG XIX

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