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Archive for the ‘Uncategorized’ Category

Hearing Frequencies by Rob Patterson

Thursday, July 18th, 2002

Making a live set-up sound good may have as much to do with your ears as it does with the room.

We have 2 all heard feedback at one time or another, but did we know what frequency was ringing? I’m sure almost all guitarists know that the A above middle C is 440Hz, but not everyone knows what frequency the next A going up the scale is. You guessed it, 880 Hz. With a little experimenting and some simple math, I’m sure most people will be able to guess at least in the ballpark of what frequency is sounding off. For those sound engineers who think they have perfect pitch (if that exists), here’s a way to find the frequency of a specific note: Multiplying the frequency of any known note (ie: A 440 Hz) by 1.059546 will give you the frequency of the next note up the scale (A# 466.2 Hz). Here’s the point to all this – getting to know your frequencies just by hearing them will take some of the guess work out of your EQing. Use any instrument you can get your hands on to give you sound to experiment with (even if it is controlled feedback). I’ve included the math as it might answer some of those questions you thought were too stupid to ask. By the way … what is a one-third octave EQ anyway?

Rob Patterson – freelance sound engineer and MIDI programmer, Toronto, ON

Making Babies by Paul D. Bauman

Thursday, July 18th, 2002

Manufacturing – a dirty job, but someone’s gotta do it. Somebody has to make all of those fun toys for audio engineers to play with and for people to be entertained by.

But coming out with a new product can be difficult and challenging process, much akin to giving birth – the spark of an idea or identification of a need (inspiration?); a gestation period (design); labour (struggling with a prototype and shaking out the bugs – perspiration); nurturing (going into acutal production); then raising the child to maturity (dealing with production, component supply and quality control).

You might get the idea that there’s a busy bunch of seriously pregnant engineers out there! I’m proud to be a part of the process here at Adamson, where at the moment we’re in various stages of nurturing, raising, and proud parenthood. And as a distracted new product papa, I offer my apologies as this is normally a tips and advice column. To be honest, I don’t have any advice right now – I’ve been too busy with the kids to be able to tell you what to do with them! One important thing, though. Never under any uncertain terms, lend your car keys to a 1000 watt loudspeaker on a Saturday night.

Paul D. Bauman – Chief Engineer, Adamson Acoustic Design Corporation, Pickering, ON.

I Can’t Hear The Words by John Carr

Thursday, July 18th, 2002

I’ve often experienced artists who come in for a recording project and are producing it themselves or bringing in their own engineer. They have done their homework, the tracks are hot and the songs sound very good; but it’s the mixdown mode I’d like to zero in on here.

They have written exciting material; they have rehearsed it well and recorded it, yet I find when mixing they invariably all seem to let the lead vocals sit well down in the mix. As the writers, they know what the song is saying “I can’t hear what’s being said (or sung).” Basically the song has been lost if it stays that way.

If an A&R rep or publisher hears it like that, they’ll say the same thing too.
Always try to put your best foot forward. Be open to suggestions and, above all, take the time necessary to achieve your goals.

John Carr – Owner/Manager, Street Brothers, Toronto, ON

‘MONO’ Is a Four-Letter Word by Eric Abrahams

Thursday, July 18th, 2002

Long after some Einstein engineer figured out that music sounds better coming out of two speakers rather than one, and someone else discovered the pan pot, the dinosaur known as ‘mono’ insists on existing. Virtually all the blame for this can be placed on A.M. radio, Ford half-tons, and television, with their shitty litle 3″ speakers. As a result, engineers still have to ensure that their mixes are mono-compatible and that half of the instrumentation doesn’t fall out when mono is pressed.

I have always found the biggest culprit to be multiple miking techniques on pianos, guitar cabinets, and the like. Although it is virtually impossible to determine if your mic placement is phase coherent before actually listening to it, a little planning and common sense can go a long way towards minimizing Tylenol intake.

If, for example, the idea is to produce a stereo image from a single guitar cabinet, a pair of mics is obviously required. since increaded distance from the edge of the speaker cone decreases bass response, setting up a stereo configuration in the middle of the front of the cone isn’t going to do it, unless the desired sound is thin. If one micgets moved to a placement, say 2″ in from the edge of the cabinet, 1/2″ away from the grille, and a foot above the floor, set the other mic up as a mirror image on the other edge of the cabinet. Instant Phase-Coherent Microphone Placement, Just Add Level. At such close distances to a source, a small movement results in a largephase shift. If one microphone is 1″ away and the other is 2″, it takes the sound twice as long to reach the second mic as it does the first, and there is a 180 degree phase shift – perfect cancellation – at 6600 Hz, the frequencywhose wavelength is 2″. This should also be remembered for subsequent overdubs. If the original bed track guitar was done with the two mics 2″ away from the speaker, and, at a later time, the guitarist doubled his rhythm part but the pair of mics was 4″ away this time, each of the stereo guitars on tape will be phase-coherent within themselves but not together. This time, the problem will occur at about 3300 Hz., a 4″ wave-length. Isn’t modern technology wonderful? Engineers will be haunted with this until mono is abolished and North America catches up with Japan in the TV department. Pray it will happen soon.

Wouldn’t mixing be so much easier if we ahd just one ear in the middle of our foreheads? But, then again, we’d look pretty silly talking on the phone.

Eric Abrahams – Head Engineer, Cherry Beach Sound, Toronto, ON. (Credits include: Kim Mitchell, Trash Gallery, Roxy Lane, Russian Blue, Dreamer, Nicola Vaughan, Angel Marr.)

Revelations by Eugene Martynec

Thursday, July 18th, 2002

I was doing electric guitar overdubs on the first Kensington Market album in the late sixties and I was getting frustrated by my terrible guitar sound. I asked producer Felix Pappalardi (Felix was enjoying huge success with Cream at the time) how Eric Clapton got such a great sound. He said that they put a mic in front of his amp and he played. Simple! He supplied most the great sound. I later found out that this was the case with all good musicians and that the studio was an enhancement tool, not an apology for poor listening habits from the musicians. Years later I got a classic question: “Can you make me sound like Jimi Hendrix?” My retort was, “If you can play like him, we can certainly make you sound like him.”

Eugene Martynec – Juno Award winning Producer (now represented by SRO Management in Toronto); Instructor at Harris Institute for the Arts, Toronto. (Credits include: Bruce Cockburn, Edward Bear, Murray McLauchlan, Doug & the Slugs)

Stereo Imaging by Neil Muncy

Thursday, July 18th, 2002

Just about everyone uses “nearfield” monitors. While most of these little speakers are amazingly rugged, every so often a problem will develop which affects the stereo image. Good imaging requires matched speakers. If you think you are having imaging problems, or just want to see how well matched your nearfields are, here’s what you can do to test them using only a piece of wire, your ears, and a blanket!

Make a “Y” cable, so that you can feed both speakers from the same power amplifier channel. Connect the speakers, making sure you observe the same polarity for both. Position the speakers on the console so that they form an equilateral triangle with your seated position. Orient the speaker cabinets so that the tweeters are above the woofers. Start the music, and find the centre using your ears. If both speakers are well matched, you should sense that all of the sound is coming from the midpoint between two speakers. Then, to reduce reflections, cover the control surface of the console with a thick blanket. The image should get even tighter and more centred. Next, turn the two speakers so that the drivers are facing each other, and move them together so that they are as close as possible. You should hear a slight increase in sound output. Now reverse the connection to one speaker. There should be a dramatic drop in sound, with all of the low frequencies, and most of the highs, completely missing. If there is any substantial soudn remaining, there is something wrong with one or both speakers. (This test assumes that the drivers are mounted one directly above the other, or that the cabinets are sold in mirror-image pairs).

If your speakers fail these tests, comparing each one individually with another unit which is known to be good shoudl pinpoint the defective unit. If your speakers pass these tests, but the imaging is still “off” under normal conditions, chances are that there is an electrical problem somewhere in the monitor chain, and it may be time to call your maintenance technician.

Neil Muncy – Neil Mancy Associates, Ltd., Consultants in Electroacoustic Systems, Scarborough, ON


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