Sunday, October 16, 2011

Check Your Cables Before You Take Your Gear Apart!


Everyone in the recording industry talks about the sound of transformers, and vintage gear is still used in every major studio mainly because of the wonderful properties of tubes and audio transformers. Talking specifically about output balancing transformers, they tend to not only give the sound a particular coloration (most of the time a desired one), but they also create the perfect true servo balanced output only if the ground connection on the output jack (usually pin 1 of an XLR plug) is taken in consideration.
It is very important to use true balanced connections on devices that contain audio transformers on their inputs or outputs. And if an unbalanced connection is required (for some odd reason), make sure you ground the unused pin of that connection. For example:
A mic-pre like the Neve 1073 would have a transformer on it’s output. If the XLR cable used on the output of it looses let’s say pin 3 (the negative or inverted signal in a balanced connection) normally you would expect about 6dB of level loss. Not that big of a deal right?...Wrong! Not only would you lose useful signal, and decrease your S/N Ratio (Signal to Noise Ratio) but also the whole frequency response would change. You would lose most of the low frequencies depending on what kind of a gear you are going in to after the 1073. The reason for that is because the transformer on the output really would not have much to do with the ground of the device. When you lose one of the active pins on a balanced connection (pin 2 or 3 of the XLR) all you have left is one active pin and the ground. In a sense you would be trying to sort of bypass the transformer and “mess” with the audio before it hits the output transformer, because ground is usually present in the primary winding of an output transformer and not really connected to the secondary – (final output) of the transformer. That of course is not always the case but if you end up with a super week signal with no low end coming out of your Neve mic pre, check your cables first before you take it apart. 


Tuesday, August 16, 2011

Customer Satisfaction in the Recording Studio

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The clientele and the size of the business of any recording studio are always determined by the satisfaction of their clients. A lot of engineers, producers and studio owners don’t realize that the recording industry is not just product-oriented business, but a service industry as well; like a restaurant for example. Yes the quality of the food is very important, but the total atmosphere and the attitude of the waiter are just as important. As an engineer, I feel like the final quality of the mix for example is just as important as the process that delivered that final mix. Since music and the recording process are very subjective and not tangible, there are a lot of situations that remind me of the fable "The Emperor's New Clothes". For example an electric guitar track recorded through a $5,000 microphone will always sound better to the untrained ear if that person knew the price of the microphone, even if a $75 microphone is way more appropriate for the job. See the article “The Essential Microphones - The Shure SM57 & the Neumann U87” http://ezinearticles.com/?The-Essential-Microphones---The-Shure-SM57-and-the-Neumann-U87&id=1777297
 At the very beginning of my career as an engineer I was fortunate enough to work with great engineers and producers. As an assistant engineer I’ve witnessed the following scenario in the studio on more than one occasion:
After 8 or 10 hours of working on a mix the engineer is pretty happy with the sound and ready to print the final mix and go home. Instead we find out that the record label executives, A&R, or the band’s managers are on their way to check on the progress of the song. Two minutes before they walk in the control room, the engineer takes the bass track and turns it way down, to a point where you can barely hear it. After the A&R guys heard the mix they all agreed “It’s perfect, except it needs more bass”. The engineer brings the level of the bass back where it used to be, and everyone approves the mix and goes home. Later he explained to me that if he hadn’t done that, we were all going to spend the entire night trying to find a flaw in the mix so that the A&R guys would feel like they contributed somehow to the great final product.

On many other occasions when working with an inexperienced producers, as an engineer I’m forced to play mind games. For example I might be asked to ad more effects on a vocal, when it’s obvious to me and everyone else in the studio that the vocals have too much effect already. In this case I would pretend I’m adjusting the effects while doing nothing, and magically the producer feels like the vocals sound so much better now.
 The studio I worked for a few years ago had a few thousand dollars extra in their budget. The dilemma was whether to buy the latest model ribbon microphone, or a giant screen TV with Play Station and X-Box. Guess what, we ended up getting the game system. Having good microphones and gear is very important, but that only satisfies the engineer. The real paying clients in the studio are the artists and the record labels behind them. Getting them occupied while doing the tedious techy stuff in the recording process, turned out to be more lucrative then getting the shiny microphone. See article by “Record Productions” http://www.recordproduction.com/sanctum-sound.html
All those examples prove that client satisfaction in the recording studio includes the process of getting to the final product as well as the product itself. Many studios I’ve been to, don’t take that in consideration. They focus only on the technical aspect for the project, not realizing that even with a great sounding final product, they are providing a horrible service to their clients.

Wednesday, August 3, 2011

Time Management in the Recording Studio.

--> Managing your time in an efficient way when in the recording studio is the most important skill you may learn as a producer and an engineer. Almost every session I've worked on in my life has ended late with not quite everything scheduled done.

Make the most of your time in a recording studio: 10 great tips

written by: Alex Fraser; article published: year 2007, month 11

Two main reasons recording budgets always run short - poor time management, and personal conflicts between band members, engineers, producers, A&R. If you take both of those factors out, every record should always turn out as planned. The reality is that we can’t quite predict other people’s actions and avoid confrontation. With a little experience we can definitely foresee the amount of time needed for a particular task in the studio. What most producers usually don’t accommodate for in their scheduling is the time it takes to resolve the personal conflicts. We all tend to ignore the human factor in everything we do, but it is a very real condition that’s unavoidable. For better or worse we are all humans. Because of that human factor, a lot of times our ambitions are higher than what we are capable of doing. In general that’s a good thing, but when it comes to studio time, the opposite has proven to be more efficient. Don’t go in the studio with a huge plan for the day. Be well organized, but don’t try to schedule every second of the session. A well-rehearsed band can probably do six basic tracks in about six ours of recording time. The same band with the same songs on a different day might do only three songs in the same given time. That’s the reality of it when taken the human factor in consideration. So don’t plan on getting six tracks in six ours. At the same time studio time and tasks performed never have a linier relationship. If you can record six tracks in six hours that doesn’t mean you can record three tracks in three hours, nor does it mean you can do twelve tracks in twelve hours. Time management in the studio always comes down to preparation. Think of your session time as a robot that needs to run on autopilot. If you didn’t program it well at home it will crash and burn and there’s nothing you can do about it. It’s usually a fine line between preparation and setup time vs. session time. If you need to print scores or learn lyrics obviously that would be a part of your personal preparation you can do at home ahead of time. When it comes to the actual physical setup in the studio a lot of times that’s done right before the downbeat of the session or sometimes as a part of the session time. All those factors should be taken in consideration to achieve effective time management in the studio. The producer of the session should be the one responsible and act as the time manager, but a lot of times no one takes control and sessions run into a grinding halt, mainly because of a poor time management.
See also "Top 5 Recording studio tips" by Joe Shambro

Tuesday, July 12, 2011

Does Audio Cable Length Matter

The length of your cables does matter. Not because the signal gets delayed if it travels through a longer cable or because it might get phase-shifted compared to the same signal traveling through a much shorter cable. The effect of the wire and cable lengths in the recording studio are so insignificant to the delay of the signal that we can just ignore them. (it takes about 0.00089 seconds or almost 1ms (millisecond) for sound to travel 1 ft in air at sea level. In order to get your signal delayed by 1ms just by adding length to your cables, it would take you about 186 MILES of cable)
The length of the cable does matter though especially if we are talking about a guitar unbalanced cable. The impedance of the guitar is so high that the capacitance of the cable would definitely affect the high end of your signal. See Gene Dellasala's detailed article on RLC losses in a cable. Also Unbalanced connections are susceptible to magnetic and Radio Frequency interference so the longer the cable the better the chances are you'll end up with unwanted hum or radio or who knows what in your guitar signal.
If we are talking about balanced microphone cable the length matters for the same reasons as the guitar cable although balanced cables tend to reject magnetic interferences pretty well. The problem with the microphone signal is that the voltage of it is so low (in the micro Volt range - 1 micro Volt = 0.000001 Volts) that after amplifying it 40-50 dB or so it is very important that the cables pick up absolutely nothing on the way to the mic-pre input. Also I personally had the weird experience with the Sony "Solid Tube" Mic (more than once on 2 different mics) where I had a 3 ft "Mogami" mic cable coming out of the power supply straight in to my studio's mic panel on he wall, and I was picking up some radio station. First I lifted the ground on the power supply but it got worse. Then I changed the cable with a 15ft Mogami and the radio disappeared. Now I always use the longer cables on the "Solid Tube" until one day I had that same radio... I changed the cable back to the 3-footer and the radio was gone. Maybe just a coincident or some capacitance match or who knows what... My point is CABLE LENGTH MATTERS.
If we are talking about speaker cable, a lot of people have the miss-conception it's OK to run Speaker Cables as long as you want. It is both true and not. Speaker level has the highest voltage and the lowest impedance out of all signal levels used in a recording studio. In that sense it is safest to run the longest runs. On the other hand, because of it's super low impedance the resistance of the wire makes a big difference on the power at the other end. Depending on the speaker cable a 50 ft run, depending on the gage, may have a total of 2 to 4 Ohms of resistance. If your speaker's impedance is 4 ohms and your amplifier is rated to drive 100 watts over 4 ohms (assuming) the wire resistance is 0 ohms, you'll get your full 100 Watts. What happens when you put your speakers 50 ft away from the amp... the resistance of the cable gets added to the 4 ohms of impedance of the speaker for a total of 8 ohms. Now the same 100 Watt at 4 ohms amp has 8 ohms of load instead of 4 ohm giving us only 50 Watts. Power(Watts) = E squared divided by the Resistance (impedance) where E=Voltage which is constant in the above example. Note the use of resistance vs impedance and vice-versa. We use resistance when we are referring to DC circuits, and Impedance when talking about AC circuit - all audio signals are AC (Alternating Current)
 See also the following blogs on this topic:

Saturday, July 2, 2011

Phase Vs. Polarity

Phase has to deal with timing and waveforms developing over time.
Polarity on the other hand has nothing to do with timing. It is purely a matter of direction of flow of electrical current.
You've probably heard the term "Out of Phase" or "180º Out of Phase" 99% of the time people use this term when they mean "Reversed Polarity" Almost every mic preamp or a console out there has a "Phase flip" switch, which is misleading. All that switch does, is reverse the polarity of the signal. Since it clearly has nothing to do with the timing of the signal it should not be associated with "Phase". 

CORRECTING PHASE WITH REVERSING POLARITY.
Phase problems or issues occur every time we have two or more instances of one source of sound. For example…
A guitar miked with more than one microphone, or a direct signal from a bass and a split of that same bass going through a bass amp which we've miked, or a close-miked drum-set and a room mic picking up that same drim-set. In all of the above examples we have one source of sound and more than one physical location where we capture that sound. Considering the speed of sound in air (1125 ft/s) it makes sense that one of our instances of that source would run slightly behind the other - (timing differences equals phase differences). The effect of the wire and cable lengths in the recording studio are so insignificant to the delay of the signal that we can just ignore them. (it takes about 0.00089 seconds or almost 1ms (millisecond) for sound to travel 1 ft in air at sea level. In order to get your signal delayed by 1ms just by adding length to your cables it would take you about 186 MILES of cable)
So you have your two mics on your kick drum for example - (one inside and one outside of the drum) about 1 ft away from each other. The outside mic will pick up the sound of the beater hitting the head about 1ms later than the mic a foot closer to the beater. So considering the speed of sound again, frequencies around 1125 Hz may get a boost while frequencies around 562.5 Hz may get lost. If we reverse the polarity of one of the two mics in theory the frequencies around 562.5 should get a boost and the range around 1125 Hz should disappear. Yes and NO. If we work with pure sine waves that would be the case - Before we reverse the polarity of the mic 1025Hz sine wave would fall exactly 360 degrees shifted over the distance of 1 ft and double itself in amplitude, while 562.5Hz sine wave would shift exactly 180 degrees over 1ft, so it would cancele itself completely. But since we are dealing with a complex waves and not just a pure sine wave, plus the fact that the two mics are probably different models and they pick up the sound of the drum at different locations of the drum itself, the two signals would have different frequency content to begin with. So after we combine them together we get a third frequency content of the sound of the drum. By flipping the polarity of one of the mics we drastically change the combined frequency content but that doesn't mean we completely lost our 1kHz range. Depending on the drum the mics the positions and also the rest of the drum mics like over heads and rooms you may end up reversing the polarity of one or two mics so you can get the desired sound... There is no right or wrong way... Just experiment and trust your ears. Rule of thumb is If you have two mics that are close to each other - 6 inches or less and you would like to mic some kind of a low frequency source - bass amp kick drum, guitar amp etc. make sure the polarity on of both mics is the same. After summing or mixing two microphones that have timing/ phase differences in the sound they are picking up, we create what's called a "Comb Filter". By reversing the polarity of one of the microphones all we do is shift the frequencies that get boosted and the ones that get cancelled out. In either case we end up with a severe EQ curve. At this point It is just a matter of preference and overall desired sound.


Also see article by "Musician's Friend" on the same topic.