Trev - This response is specifically to you, but others may find the info useful
You stated that you had downloaded YMEC DSSF3. Now, when you've got the hang of it, not forgetting to calibrate your mic (very important obviously). Take a sound spectrum measurement and save it. Open the Sound Analysing System, open the saved file, and begin with looking at the Spectrum tab. Start for a couple of seconds and stop it - Click Screen Copy and choose a place to save the spectrum image. Right click on the image and choose image file; name it, and save it. Go to it and open it with an image viewer - You can zoom in and out on it now. It's ALL in the Spectrograph - Every bit of energy in whatever form - All you have to do is approach it knowing more-or-less where to look. The scan is from 0Hz to !0KHz - First look at 50Hz power. Do you have a small sub and interharmonic, say 2-3Hz, left and right of 50Hz? That would be commutation of band-pass filter capacitors on the mains. The thyristor (electronically) switched type. Do you have a spike at ~75Hz and/or ~275/280Hz? Do you a LF subharmonic of these at ~30Hz or ~24/26Hz? Do you have a subharmonic in the 1250Hz range? Or the 158/160Hz range? Same culprit. If you do you know what they are, don't you Trev? They are actually sub-subharmonic hybrid sine waves. Now you know why nobody has ever found them - They weren't looking! The energy escapes at the joint where the capacitors are connected to the power line. "For every force there is an eaqual and opposite reaction force". "Energy can be neither created nor destroyed" - This law means that "....energy can change its location within the system, and that it can change form within the system..." and that's it, energy don't (sic) just disappear, it simply changes from one form to another - i.e. Cemical to Kinetic, Electrical to Sonic, you on the roof to a hole in the ground! :) Merry Christmas to all our readers (The Beano used to tell me that when I was a kid!) On Dec 20, 7:36 am, Trev <[email protected]> wrote: > I have a large woofer put by for just this task. > My main problem is that Hum for me is non stop, pretty well through > the year- and not at a high level. > It certainly doesn't go ON/Off like some have reported. > Operating in the dark is not easy ,with no variation in ambience to > connect with. > Maybe why I divert to wider range scenarios where other ideas may be > scraped up from contributers. > Yeah, Vic- not many people have studio standard gear anywhere to hand > at work, let alone at home. > > On Dec 20, 2:02 am, Vic <[email protected]> wrote: > > > > > Some that make recording attempts of these low-frequency sonic waves > > probably succeed to some extent. However, from experience I, for one, > > am aware that equipment is manufactured to only record sound that > > occurs in the "normal" band of human hearing. Manufacturers are hardly > > going to produce products that don't sell in the millions- Supply and > > Demand - Particularly in our present "New World Order" where Chinese > > factories are tailor-made to fit the multitude of consumers in the > > West. > > > To do the job right, you need the right tools.......... > > > These successful (together with the unsuccessfulful) recorders make 2 > > fatal mistakes: No reference frequency and playback speaker choice. > > > I do not believe that and have proven that an expensive microphone is > > not required. Mylar is quite satisfactory with a sampling frequency > > rate of 44KHz. computer sound cards are ubiquitously "excellent" in > > quality, their driver software likewise - They are universal (see > > above 1st para). The universal calibration frequency is 400Hz > > (remember the years-ago black and white TV's "Off The Air" picture and > > accompanying 400Hz sound?), This is not a satisfactory frequency with > > "Hum" - 440Hz, the ultra-stable note of A4 is required. Sound is a > > logarithmic function of energy wave disturbance in the atmosphere. The > > Octave function rather than the Frequency function is required. I > > utilized the Fast Fourier Transform Technique to analyse the B0 and B1 > > octaves coupled with AP Tuner, DC Live 7.5, and DSSF3 with success. > > > 2nd. (apparent) failure reason: Normal speaker diaphragms simply lock- > > up and are "glued" to the magnet at these low frequencies All that is > > produced is a high frequency feedback sound. What you need is a > > MASSIVE sub-woofer - That'll work! And I've done it. > > > No one has to actually audibly playback "Hum" - After all, only a > > certain few would hear it anyway. A "waterfall" graph could be used, > > or Spectrograph, or, the previously merntioned FFT Power Spectrum > > scan. Movement is a convincing measurement with humans; hence, I chose > > the "waterfall" for my presentation of the "Hum", backed up by the > > other 2 scans and IACC/Tau/Phi scans. "Hum" is a tough nut to crack, > > ordinary nutcrackers don't work. There are tools out there that DO > > work. I've attempted slowly introduce "Hum" ID and cracking and to > > introduce these tools to the people on this forum who are unfortunate > > enough to be able to hear this atrotious man-made anomaly. > > > Try 'em, they work. Let's go get the darn culprits and put an end this > > nightmare! > > > On Dec 19, 11:12 am, Trev <[email protected]> wrote: > > > > Maybe as the effects on the microphone are unknown, unless separately > > > calibrated for? > > > If professionals aren't sure- they will default to the known, least > > > contentious position. > > > With Hum already being a tricky problem, makes it worse- but one might > > > infer some of these testers had a more biased lean, from what you say, > > > John. > > > A new pillow damping run needed...? > > > > On Dec 17, 3:58 pm, "john dawes" <[email protected]> wrote: > > > > > When people first begin to hear the Hum it is usually in the early > > > > hours and the instinctive move is to cover one's head with a pillow, > > > > however, as we all know this does nothing to stop the Hum. > > > > > Over the years I have met many people who have attempted to record the > > > > Hum . They have used all types of expensive recording machines and > > > > microphones with impressive specifications, however, when I suggest > > > > that the microphone should be covered with a pillow to remove > > > > extraneous noise and allow only the Hum to pass through, they are > > > > strangely reluctant to do so- Hide quoted text - > > > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "Hum Sufferers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hum-sufferers?hl=en.
