How To's ·
Measuring Stuff with Studio Six Digital's Acoustics Analyzer for iPod Touch and iPhone - Pt 2.
I went back to my office and played my Ayre Acoustics pink noise track: turned on the FFT; I was immediately greeted with a familiar noisy green line frequency response spectral display that was settling nicely as it continuously averaged over last two seconds.
An FFT analyzer performs a fast fourier transform calculation which very rapidly takes in samples of a continuously varying analog signal and spits out spectral information. In other words, play pink noise (which is a signal with equal amounts of energy in all frequency ranges), and an FFT analyzer will very rapidly show a frequency response curve. In the case of pink noise, the response should be a flat line.
Needless to say, I'm very impressed with the Studio Six Digital "Audio Tools" iPhone app.
I went back to the shop to talk a bit more to Jamey, Jorge, and the gang about the iPhone and Audio Tools as an acoustics measurements tool, and showed them how to use this device when evaluating iPod docks and speakers. We played around for a little while, and were able to see comb filter effects from first reflections of the desk surface with the docks. And the Boston Acoustics i-DS3 plus has a stereo image widening function, and we could observe the steering of the upper mids and lower treble off to the side by moving the analyser from side to side. We had a fun time playing around with this really great little audio tool, and I expect we'll use it quite a bit.
At the end of the meeting, Jamey came up to me and mentioned that it wouldn't be too hard to build a little gizmo to measure headphones with using the iTouch.
You'll never guess what I did next.
On to part 3 ---->

[caption id="attachment_589" align="alignright" width="300" caption="Harbeth HLP3ES-2 Speaker Frequency Response"]![]() |
[caption id="attachment_590" align="alignleft" width="300" caption="Ruh roh! Something's wrong with this speaker!"]![]() |
[caption id="attachment_592" align="alignright" width="300" caption="The Boaston Acoustics Duo-i plus sounds pretty darn good."]![]() |
[caption id="attachment_594" align="alignleft" width="300" caption="BA Duo-i plus with all controls set at neutral."]![]() |
[caption id="attachment_595" align="alignright" width="300" caption="BA Duo-i plus with bass and treble controls at max."]![]() |
[caption id="attachment_597" align="alignleft" width="300" caption="BA Duo-i plus with bass and treble controls at minimum."]![]() |
[caption id="attachment_599" align="alignright" width="300" caption="Duo-i plus up agains a wall with additional gain in lows resulting."]![]() ![]() |
[caption id="attachment_602" align="alignleft" width="300" caption="The Skullcandy Pipe ruuns on 4 AA batteries."]![]() |
[caption id="attachment_603" align="alignright" width="300" caption="The Pipe response is flawed, but what did you expect?"]![]() |

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