186 reputation
4
bio website bjornroche.com
location New York, United States
age
visits member for 2 years
seen May 15 at 14:45

I write audio and video software. I like to work in Java, C and C++, but whatever works. Someday maybe we'll just do everything in javascript.

Currently I'm working on Xonami: www.xonami.com

I can be reached at bjornroche.com


Sep
24
awarded  Autobiographer
Mar
22
comment Harmonic frequencies of electric guitar are detuned. What could be the cause?
The question is a bit misleading and suggests that the A on a guitar is 440 Hz, which it is not. 440 is a pretty high note. From this graph, it appears that the fundamental frequency is 110Hz (still an A) not 440. There are no subharmonics here.
Mar
20
answered Fourier transform with periodicity at the harmonic frequency
Mar
3
answered Why I hear sound from downstairs clearer than sound from upstairs?
Oct
4
awarded  Commentator
Oct
4
comment Why does the echo of the last chord appear to rise in pitch
This is possibly a psychoacoustic effect rather than an acoustical phenomenon.
Sep
25
comment Is it possible to estimate the number of people in a room from a limited number of simultaneously recorded audio samples?
This is def a DSP.stackoverflow.com question.
Sep
6
comment How to find gain bandwidth with knowledge of source bandwidth and output bandwidth? Deconvolution?
Can you control the input? If not, what is the nature of the input signal?
Sep
6
comment How to find gain bandwidth with knowledge of source bandwidth and output bandwidth? Deconvolution?
The output is the convolution of the input only if the device is linear.
Jul
9
comment Is sound relative?
Are you in an enclosed container where the wind is moving with you (like in an airplane?) or are you sticking out with the air sweeping past you at 1000 mph?
May
1
comment Is there a naturally occuring sound pressure level reference?
I'm afraid that's beyond me :(
May
1
answered Is there a naturally occuring sound pressure level reference?
Apr
21
comment How to determine frequency components present in distorted signal, with the set of possible components already known?
You need the signals and the harmonics to be far enough apart that they don't have overlapping FFT bins. Choosing prime numbers won't guarantee that.
Apr
21
comment How to determine frequency components present in distorted signal, with the set of possible components already known?
In the digital domain, DTMF is usually decoded using the Goertzel algorithm. Like the FFT, the Goertzel algorithm is essentially a DFT implementation designed for performance.
Apr
21
answered How to determine frequency components present in distorted signal, with the set of possible components already known?
Apr
20
awarded  Teacher
Mar
12
comment Calculating the mass equivalency of a song?
FWIW, people ask about measuring dB SPL on the iPhone. You would need to calibrate your iPhone first. Use a sound level meter instead. 50 bucks from radio shack.
Mar
5
answered What creates the differences between the two channels of a stereophonic signal?
Nov
19
comment Frequency of the sound when blowing in a bottle
en.wikipedia.org/wiki/Helmholtz_resonance
Nov
16
awarded  Supporter