frequency range of a song analysis?

[james45974]

Is there a way to see the frequency range of a recording?  I am thinking about a graph similar to what you see for speaker response.

 

 

Maybe I have my answer already, is the Frequency Analysis Tool in Audacity the correct tool?  How is this chart interpreted?

[Ralf11]

difference is the time dimension

 

spectrograms used to be the big thing, but there are more modern ways to do this now

[audiventory]

5 hours ago, james45974 said:

Is there a way to see the frequency range of a recording?  I am thinking about a graph similar to what you see for speaker response.

 

 

Maybe I have my answer already, is the Frequency Analysis Tool in Audacity the correct tool?  How is this chart interpreted?

 

It's right direction. When you analyze recording's frequency range it called spectrum analysis. There are many spectrum analysis tool. 

 

However, using a measurement tool depend on precision what you need. Also may be issues with available functionality.

 

As rule, you may dont concern about it for easy fast analysis.

 

But if you need something for serious proofs, need more careful approach.

 

Measurement tool should have 3...10 times and more precision than measured value.

 

As example, if you want measure with 1 dB precision, measurement tool must provide 0.3 dB or better precision.

 

Before measurements need test/calibrate measurement tool. If it is software, need test each new version, because there probable new bugs.

 

For testing need several base signals: sines on several frequencies with identical amplitudes, sweep sine in full tested range, white noise.

 

Need be carefull with overload, because it can distort test results.

 

I very recommend test measurement tools and measurement results by several different ways for sureness.

[semente]

I wonder if Spek will do the trick.

 

R

 

 

 

[james45974]

Thanks Yuri, I am curious.  I read occasionally about songs that you can use to set up subwoofers for instance and I am curious about their range.

[james45974]

On 4/9/2017 at 4:33 AM, semente said:

I wonder if Spek will do the trick.

 

R

 

 

 

Not familiar with Spek, I will have to look it up!  Thanks

[audiventory]

7 hours ago, james45974 said:

Thanks Yuri, I am curious.  I read occasionally about songs that you can use to set up subwoofers for instance and I am curious about their range.

 

James,

I have adjusted subwoofer on ears, because I havn't SPL-meter.

 

Own record (certain sequence of short bass sines) was created in audio editor. Main principle there is comparison of several frequencies during time of hearing memory or cathing of resonances. There are need several records for covering full range 20 ... 150...200 Hz.

I peak up the sequence specially for my ears and subwoofer.

I suppose, there need individual sequence for each case.

[esldude]

An FFT used with care and understanding of what it does show you and what it can miss is very useful.  That is a part of Audacity.  The spectrogram view also in Audacity can do that as well.  The spectrogram is made using FFT info so again some understanding of how it can miss things is good to know.  I could say more if you are interested.

 

A program that is very useful for this purpose with music is Sonic Visualiser.  Shows waveforms, spectrograms and such too just easier to use for this purpose.  For instance one of the things it can do is plot the peak frequency in a given group of samples in a digital music file.  So you for instance have a plot of max frequency every 4096 samples for the whole song.  It does lots of other things I haven't used it for.

 

http://www.sonicvisualiser.org/

[esldude]

Just saw you are interesting in the lower end.  The FFT is probably better for telling you that.

 

I also agree with Yuri, making your own low frequency sweeps is better for setting up the subs.  Then once close switch to recordings to see if it suits you, and to make minor adjustments.  The FFT in Audacity would let you find recordings that have genuine low frequencies in them.  Most recordings don't have anything below 50 hz.   I have known people to spend an afternoon adjusting in the 50 or 60 hz range using recordings that did not have anything there.

 

In Audacity under the Analyze menu use the Plot Spectrum function.  I would set the size to at least 16,384.  If you set it too small you don't have good resolution at low frequencies. Set the axis to a log frequency plot.  Every real recording is likely to have some low frequency garbage.  It usually is obvious about where the response drops off however. You also can select to analyze short segments that you know from listening have drums or other low end sounds.

[james45974]

20 minutes ago, esldude said:

Just saw you are interesting in the lower end.  The FFT is probably better for telling you that.

 

I also agree with Yuri, making your own low frequency sweeps is better for setting up the subs.  Then once close switch to recordings to see if it suits you, and to make minor adjustments.  The FFT in Audacity would let you find recordings that have genuine low frequencies in them.  Most recordings don't have anything below 50 hz.   I have known people to spend an afternoon adjusting in the 50 or 60 hz range using recordings that did not have anything there.

 

In Audacity under the Analyze menu use the Plot Spectrum function.  I would set the size to at least 16,384.  If you set it too small you don't have good resolution at low frequencies. Set the axis to a log frequency plot.  Every real recording is likely to have some low frequency garbage.  It usually is obvious about where the response drops off however. You also can select to analyze short segments that you know from listening have drums or other low end sounds.

Thanks esldude I appreciate your answer.  Right now for me it is more curiosity about how some people do their setups.  I don't have subs in my current setup but I don't want to never say never!

[esldude]

14 minutes ago, james45974 said:

Thanks esldude I appreciate your answer.  Right now for me it is more curiosity about how some people do their setups.  I don't have subs in my current setup but I don't want to never say never!

Well in that case, get an inexpensive calibrated measuring microphone and download free REW.  That is so much better than any other way of setting up subs I know about.  The software was designed specifically for that purpose originally though it does more than that now. 

 

These were done with a $85 UMIK 1 USB mic.  That and a laptop is all you need once you download REW.  You can see my video speaker here.  The terrible peak at 34 hz is a room length mode.  That and the dip around 55 hz are major problems in this location which is where I initially placed the main speakers (this actually is without a sub).  The waterfall plot also shows me my room needs some more damping.   There is a learning curve to make best use of it of course.  I don't know of a better way to setup subs short of paying someone else so you don't have to do it.

[Ralf11]

some background in acoustics will help too