#Setting up fuzzmeasure how to#
#Setting up fuzzmeasure Pc#
#Setting up fuzzmeasure mac#

The second curve however shows that the port output of the unnamed speaker is characterised by a series of resonant features. Apart from a couple of minor, potentially resonant features, the output decays slowly into noise.

The first curve shows the Pioneer RM07’s well behaved port output. One interesting technical feature of the RM07 is the effort made to suppress port ‘organ pipe’ resonance, and I illustrated this in the review by using FuzzMeasure to generate port mouth response measurements of the RM07 and a not dissimilar, unnamed speaker (in which no apparent effort had been made to suppress those port resonances). The first use of FuzzMeasure in a review was in the July 2016 piece on the Pioneer RM07. Note the vortex generating edges on the port exit flare and the damping pads just visible inside the port. The idea is not to use acoustic measurements to turn monitor reviews into dry technical appraisals, but to use measurements to illustrate aspects of interest in any particular monitor. I’m blogging about it now however partly because it’s recently been updated to Version 4 (4.1 in the last day or two), with numerous enhancements and improvements, but also because I’ve begun to use it to illustrate the nearfield monitor reviews I write for Sound On Sound magazine. I first experimented with FuzzMeasure not long after it launched and have used it a on a few speaker design projects. One great advantage of swept-sine wave deconvolution over MLSSA’s minimum length sequence technique is that it can generate harmonic distortion data, something that MLSSA can only do in a somewhat clumsy spot frequency mode. FuzzMeasure uses an advanced mathematical technique called deconvolution to derive an impulse response from a fast sine sweep, which, again using a Fourier transform, can generate a variety of frequency domain data. That all changed however with the launch in 2004 of a neat little OS X app created by Chris Liscio called FuzzMeasure.

#Setting up fuzzmeasure mac#

Windows users were well catered for with MLSSA and a couple of later competitors, but we Mac users for a long time had to borrow a PC or, as I did for a while, buy a cheap and clunky laptop just for the electro-acoustic stuff. The one thing however that time domain based acoustic measurement lacked during its first couple of decades was a Mac based app.

#Setting up fuzzmeasure Pc#

Suddenly, complex time domain based acoustic measurement was available to anybody with a PC and a couple of thousand dollars. The real sea-change occurred however when Douglas Rife took Stanley Lipshitz and John Vanderkooy’s Minimum Length Sequence technique and created a comprehensive DOS based acoustic analysis package, christened MLSSA (pronounced Melissa). The Time Delay Spectrometry technique devised by Richard Heyser was, for example, soon packaged up into the relatively affordable TEF acoustic measurement system. Time domain measurements were the beginning of the end for swept sine-wave techniques. It was as if somebody had photographed the dark side of the Moon. The resulting ‘waterfall’ plot, that illustrates how speakers go on ‘playing’ after an input signal has stopped, was a revelation. This could not only generate the speaker’s ‘steady state’ frequency response, but also its frequency response at any time after the impulse.

One in particular, Laurie Fincham at KEF, realised that computers made possible recording a speaker’s response to a short impulse and then applying a Fourier transform to translate between time and frequency domains. The arrival of cost-effective computing power in the 1970s didn’t go unnoticed by loudspeaker engineers. First, it needs a large anechoic chamber to produce accurate results at low frequencies, and second, it reveals very little about a speaker’s time domain performance how well the speaker starts and stops in response to an input signal. For all its slightly Heath-Robinson appeal though, Brüel & Kjær style swept sine-wave measurement had, and has, two big problems.

Once warmed-up, the Brüel & Kjær kit could spit out wonderfully intuitive and revealing swept sine-wave frequency response and distortion charts.

#Setting up fuzzmeasure how to#

One of the first things I learned was how to use a set of classic Brüel & Kjær acoustic measurement equipment comprising a measuring microphone, a combined oscillator/preamp/ analyser (one of these) and a paper chart recorder (like this). I’ve been measuring speaker performance ever since I washed-up at Mordant-Short in the early 1980s as a raw design graduate.