I primarily listened to the LiveX ELX112P and ZXA1 full-range powered loudspeakers, even though EV coupled these cabinets with corresponding powered subwoofer models.  Fortunately, the demo allowed me to listen to the speakers without the subwoofers at moments.

I found that the LiveX model exuded an adequate SPL, but the frequency response from the entire cabinet did not sound nearly as flat as other EV models with which I am more familiar.  The high end seemed to be pronounced and over exaggerated while the middle/low end seemed to excite and resonate the relatively thin wood of the ELX112P cabinet.

The ZXA1 impressed me.  The relatively small and light-weight injection molded cabinet with the 8″ woofer (compared to the 12″ woofer in the ELX112P) seemed to outperform the ELX112P on many fronts.  The ZXA1 can get out right loud, and I do not mean the side of “loud” that one constructs from timbral features in the sound source.  The combination of the molded enclosure, the drivers, crossovers, and the amplifier concentrate the loudspeaker’s compressions and rarefactions in ways that the ELX112P does not.  Initially, I assumed that there would not be a fair comparison between 8″ and 12″ cabinets in the parameter of frequency response.  Typically the wider the woofer’s diameter, the lower the loudspeaker’s range.  My comparison between the ELX112P and the ZXA1 reminded me of the extent to which other factors can trump woofer size in determining frequency response.  Certainly, these factors include features pertaining to the drivers, the materials of the cabinet, crossovers, and ports, among many others.  “Shape” is one of these factors that differentiates these two models.  A top view of both models shows that the ELX112P has a squared shape while the ZXA1 has a triangular shape.  I suspect that the ZXA1′s triangular shape somewhat resembles the acoustic properties of a horn or an ‘acoustic amplifier.’  This difference in shape could contribute to the ZXA1′s amplification and low frequency reproduction.  I heard the ZXA1 as the more intense and deeper loudspeaker, even though it was so much smaller.

Here are some of the specifications for the two models to which I listened the most (find more details at http://www.electrovoice.com/family.php?id=174):

ELX112P

ZXA1

- Two channels of professional-quality 24-bit/96kHz audio input and output
- Two balanced XLR inputs, with selectable 48V phantom power on each input – Maximum input – +4 dBu setting: 20 dBu; -10 dBV setting: +8 dBV
- Mic Pre-amp gain: 10 to 75 dB
- Two unbalanced high impedance instrument inputs
- One high-level stereo headphone output
- Two unbalanced -10 dBV line outputs for powered speakers
- Multi-function controller knob for volume and input gain control and assignable MIDI control
- Multi-segment LED meters to display input or output levels
- FireWire 400, compatible with Mac OS X Core Audio
- Integration and control with Apple’s GarageBand, Logic Pro, Logic Express
and Final Cut Studio (Soundtrack Pro)
- Compatible with any Core Audio-compliant audio application
- Apogee’s Maestro software for advanced control and low latency mixing

In general, I would describe the sonic contributions from the Duet as “full,” painstakingly representing sonic detail with great breadth and depth throughout the 20 – 20kHz audible bandwidth.  With that said, one might begin to wonder how remarkable this claim might be, given how many other audio interfaces claim to offer the same details within the same bandwidth.  Admittedly, I used to overlook the quality of analog to digital or digital to analog (A/D and D/A) conversion capabilities within audio interfaces.  I assumed that my Digidesign interfaces were just fine and that all I had to do was put more consideration into the transducers that I would decide to use.  However, choosing the best microphone or loudspeaker alone does not entirely determine the quality of an audio reproduction.  High quality digital audio recording demands that we also seek desirable A/D and D/A converters.  ‘Nyquistian’ sample rates, as impressive as they might seem, do not guarantee the effectiveness of a converter.  At least two other factors determine the prowess of the A/D and D/A converters within audio interfaces: the clock and dither.

A/D and D/A conversions, in most audio interfaces like the Duet, utilize a pulse code modulation (PCM) system.  Thanks to Charles Nyquist and other scientists who implemented his theorem, the PCM sample rate must be twice that of the frequency bandwidth of the analog audio signal.  In the case of an A/D conversion, the clock generates the sample frequency for flowing binary codes that will quantitatively represent the frequency and amplitude dimensions of the analog input.  Dither is a noise that a PCM system applies to an incoming analog signal in preparation for the moment of conversion.  The complexity of this noise determines how well the converter can represent the details of an analog version in a converted digitized version.  How consistent and reliable this clock outputs this digital ‘pre-data’ that will represent the analog signal primarily determines the success of the converter.  A customized dither that anticipates and counters the imperfections the latter stages within the PCM converter, adding noise energies to the analog input signal in order for listeners to better recognize features in the digital representation also determines the success of the converter.

Apogee prides themselves for the proprietary dither and C777 clocks in their interfaces such as the Duet.  This combination has been the basis for the accumulation of a large number of engineers and musicians who use Apogee products.  While I have split the glory of this type of equipment as coming from both dithers and clocks, I now must conclude that the clock more singularly undergirds the triumphs of interfaces and their converters.

There seems to be something very human about clocks like the C777, as if it shows up to a job on time like a good and reliable worker…

On one hand, the widespread use of this microphone seems to produce a sound that is very familiar among listeners, engineers, and musicians. On the other hand, expectations for this microphone sometimes trump the possibility for engineers and musicians to experiment with different vocal microphones. These other options might differently enhance the timbre of a singer’s voice or reproduce this sound in ways that foreground the voice within a particular mix or the potentially challenging acoustic space of a listener.

Companies such as ElectroVoice, Sennheiser, AKG, Peavey, Audix, among others, have tried to compete with the 58. In certain instances, they have made microphones that represent a wider frequency bandwidth, wider dynamic ranges, or offer different pickup patterns (i.e. supercardioid or hypercardioid). Some of these microphone manufactures have also offered microphones of lighter weights while maintaining a structural stability/rigidity that is comparable to the 58. My upcoming blog posts will investigate some of these other microphones.

As any of us know, there are many ways to creatively make musical sound by constantly trying new forms and versions of audio equipment. Why does this mic seem to act as the premiere gatekeeper to the live mediated singing voice, since it is by no means unilaterally better than similar microphones?

Maybe the answer to this question is not electroacoustic. Quoting my undergrad professor, there will be “more on that later…”

Soon I will begin blogging about microphones, loudspeakers, mixers, amplifiers, interfaces, recorders, and many other types of audio equipment. As I am sure you are aware, there are many different blogs that describe these types of gear. My goal is to participate in these descriptions while also thinking through some of the many social and musical effects that these items determine.

Please stay tuned..