Errata - Beginners guide to microphones

I just read J-Sun's beginners guide to microphones, and here are some necessary corrections:

"There are only really 3 general types of mics Dynamics, condensers and ribbon mics [...]"

Correct: Today there are two general types of microphones for recording music: dynamic and condenser. Ribbon microphones are a special case of the dynamic category.

"The size of the diaphragms in the condenser mics have a big impact on the sound. Larger ones are usually better and are considered to have a smoother, fuller sound."

Correct: Larger diaphragm capsules (usually) have greater electrical output and lower self-noise than smaller diaphragm capsules, but the latter (usually) have better transient response and less coloration of sound coming from off-axis.

"The sounds that are picked up from the sides of the cardioid mic are altered or colored sometimes […]"

Correct: Higher quality (and more expensive) microphones generally achieve a smooth frequency response all around. Please consider though that the polar charts (usually) only display the response for sound arriving on a uniform vertical plane! Sound nearly always gets bounced off the floor and ceiling also.

Regarding omnidirectional microphones it is said that "Picking up alot of the room (ambient sound) also causes a big increase in the low frequency response the closer the mic gets to the sound source."

This is completely wrong! Omnidirectional microphones exhibit no proximity effect--an increase of bass-pickup when the capsule is placed close to the sound source--, which is most prominent in bidirectional (fig-8) microphones and to a lesser degree in microphones of cardioid characteristic.

Sadly this goes on: "Due to this most omnidirectional mics have a high-pass filter (HPF) that reduces some of the bassiness."

Correct: Most omnidirectional capsules are flat towards frequencies you usually don't want to record, like the rumble of air conditionings, subways, planes overhead etc. A high-pass / low-cut filter spares the capsule's internal preamplifier from LF-overload.

The statement, that the use of omnidirectional microphones is beneficial because... "On the plus side it can make your vocals sound fuller."

...is wrong because of the fact that fullness is attributed to the proximity-effect that omnidirectional microphones do not exhibit.

"Some of more expensive mics have switches that allow you to switch between different pick-up patterns."

Correct: There are many expensive single-capsule single-characteristic microphones. Dual-capsule condensers have switches to select how the two signals are combined. E.g. electrically summing the signals of two cardiod capsules, facing in opposing directions and mounted back to back, results in an omnidirectional characteristic of the system.

Linguine with asparagus & red pepper in a cream sauce

I recently came up with this receipe:

• Peel 1 lb of asparagus and steam it in the pasta pot
  
• take out the asparagus when it's done (test with a fork)
  and save the water in a cup
  
• cut the asparagus in half and quarter each stalk
  
• start up the water for the Linguine (I like the De Cecco variety)
  
• cut open & clean three red peppers, then slice them into thin stripes
  
• heat up a chunk of butter and a generous amount of olive oil in a pan
  
• insert the pasta into it's pot while stirring
  
• gently fry the asparagus and pepper strips
  --don't forget to regularly stir the pasta--
  then, after about 6 minutes...
  
• check the pasta regularly to see if it's al dente
  
• turn off the heat to the pan,
  add the asparagus cooking water, 125ml of cream
  and some freshly ground black pepper
  
• drain the linguine in time and
  mix with the sauce immediately (!)
  
• you might want to add some freshly grated parmigiano

Enjoy :-)

Recording at 32 bit (float)

Researching the web for information on the benefit of tracking at 32 bit (float) rather than 24 bit (fixed) I came accross an informative page on Audacity's website:

"Normalised floating point values are quicker and easier to process on computers than fixed integer values and allow greater dynamic range to be retained even after editing. [...] With floating point, rounding errors during intermediate processing are negligible.

The (theoretically audible) advantage of this is that 32-bit floating point format retains the original noise floor, and does not add noise. For example, with fixed integer data, applying a compressor effect to lower the peaks by 9 dB and separately amplifying back up would cost 9dB (or more than 2 bits) of signal to noise ratio (SNR). If done with floating point data, the SNR of the peaks remains as good as before (except that the quiet passages are 9dB louder and so 9dB noisier due to the noise they had in the first place)." [Link]

Still, this benefit is only relevant when...

• handling >24 bit (fixed) data
  
• within an engine with a wider path than 24 bit (fixed)
  
• that interfaces transparently with your system.
  

If you want to record the output of a 24 bit (fixed) ADC you need only track with 24 bit (fixed) accuracy.

As soon as you manipulate that data, before (!) recording it--which IMHO might not be advisable--you will increase the resolution, dependant on the internal bus depth of the engine / interface. In the case of Metric Halo's line of audio interfaces (2882, ULN-2, ULN-8) the bus is 80 bit (fixed), so you will gain some precision by recording the data at 32 bit (fixed). [Thanks to B.J. Buchalter for the clarification]

Music recorded with the Metric Halo ULN-8

As part of the beta team I have had the privilege & joy of working with the Metric Halo ULN-8 since December 2006. Here are links to some of the music I have tracked (in stereo and surround) with one of these amazing interfaces:

• 12baritone (12 vocalists & piano) [The embedded player is at the bottom of the page]
  
• Italian songs
  
• Music by the ensemble wavegarden...
  
• "Starlife"
  
• "Waves of Orange"
  
• Demonstration of my XYtri [5.1 DTS & stereo mp3]
  

Enjoy :-)

The ULN-8

Today the ULN-8 by Metric Halo is officially launched. It's an amazing audio interface that I have been lucky to use for the past 2-1/2 years as part of the beta-program. Nearly half of the current releases of my edition have been recorded, mixed and mastered with this outstanding tool, beginning with the production of the ensemble 12baritone.

I am very glad to have been involved in this process as it is a testimony to the fact that there do exist companies focused on uncompromisingly developing new gear with the future in mind--while improving on the past. The original specs were posted on December 2005, after nearly two years of in-house development and testing. Beta-testing began in December 2006.

What's in the box?

In German we have the saying "Eier legende Wollmilchsau" which translates into "egg-laying wool-milk-sow". The ULN-8 is...

• a remote & front-panel controllable 8-ch micpre with 92 dB of no-noise gain
  
• (with real analog sends!)
  
• and, as an electrically uncoupled alternative, 8 line-inputs
  
• sampling at 44.1, 48, 88.2, 96, 172.4 and 192 kHz,
  
• a digital routing system with 80 bit precision, outputting to 8 channels of AES/EBU
  
• (also, 8 channels of digital input...)
  
• an 8-ch preamp with digitally controlled analog gain stages,
  
• managed by an easy to configure 2.0 to 7.1 master controller,
  
• with a completely customizable DSP-matrix to boot.
  
  Not to forget...
  
• sample-accurate metering,
  
• tactile control front-panel
  
• with customizable gain readout options,
  
• MIDI I/O,
  
• SMPTE input & output,
  
• Wordclock interfacing,
  
• a dedicated headphone output
  
• and two ultra high-Z DI-inputs on the front panel.
  
• All in a portable, durable, 1 RU high enclosure
  
• and at a great price!

Did I say it sounds amazing? Well, it does. When I first linked it into my studio I spent a day just listening to my favorite CDs and own recordings. There was depth and transparency like I had not heard before. This can possibly be explained by the fact that the unit is phase flat (as well as power flat) from 0 Hz to Nyquist. You get what's there, and what's there gets you :-)