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[Ivan Beaver]

Here is part of the issue.

People use the term "flat".  AS MEASURED HOW???

THAT makes a HUGE difference.  If you are using an RTA, it is totally time blind which means anything will show up in the measurement.

Also I suspect (but have not tested-but plan on doing so shortly) that an old fashioned LED type RTA will respond different than a software based RTA (due to the slope of the filters inside-again I could be wrong)

A dual FFT type measurement is always the way I go.

I go for flat above 100hz to as high as the HF devices will reasonably allow.

Below 100hz I sometimes put a bump-sometimes a large bump depending on the particular system that is being used and musical styles and so forth.

The whole idea being that the purpose of the system is to accurately reproduce what is going into it and not color it.  Ie-provide a white canvas upon which the sound person can "paint" their sonic picture.

The purpose of the console/mic placement etc. is the brushes and the paint-NOT the canvas.

[Adam Greene]

Here is part of the issue.

People use the term "flat".  AS MEASURED HOW???

THAT makes a HUGE difference.  If you are using an RTA, it is totally time blind which means anything will show up in the measurement.

Also I suspect (but have not tested-but plan on doing so shortly) that an old fashioned LED type RTA will respond different than a software based RTA (due to the slope of the filters inside-again I could be wrong)

A dual FFT type measurement is always the way I go.

I go for flat above 100hz to as high as the HF devices will reasonably allow.

Below 100hz I sometimes put a bump-sometimes a large bump depending on the particular system that is being used and musical styles and so forth.

The whole idea being that the purpose of the system is to accurately reproduce what is going into it and not color it.  Ie-provide a white canvas upon which the sound person can "paint" their sonic picture.

The purpose of the console/mic placement etc. is the brushes and the paint-NOT the canvas.

Thanks for your input Ivan.  I am a little confused about FFT's.  It seems like most of the online information about them (including an article on this site) is written a little like an advanced tech manual.  The only FFT I currently employ is an iPad app. Audio Tools by Studio Six Digital. The basic multi tool app is only $20, however their digital interface with measurement mic is some $400.  I can plug my measurement mic in via a preamp into the analog input - just not sure if that is very accurate.  Even their own demo does not give a lot of practical info.  Such as - is there a way to tell the difference between  time, phase or accoustical anomalies on the readout?  Just not sure which to use to correct.  Certain anomalies cannot be corrected fully with eq.  I would love to say the church would hire a professional - but unfortunately, most smaller churches are just not going to use limited funds for that unless there is some kind of major problem.   

[Rob Spence]

Thanks for your input Ivan.  I am a little confused about FFT's.  It seems like most of the online information about them (including an article on this site) is written a little like an advanced tech manual.  The only FFT I currently employ is an iPad app. Audio Tools by Studio Six Digital. The basic multi tool app is only $20, however their digital interface with measurement mic is some $400.  I can plug my measurement mic in via a preamp into the analog input - just not sure if that is very accurate.  Even their own demo does not give a lot of practical info.  Such as - is there a way to tell the difference between  time, phase or accoustical anomalies on the readout?  Just not sure which to use to correct.  Certain anomalies cannot be corrected fully with eq.  I would love to say the church would hire a professional - but unfortunately, most smaller churches are just not going to use limited funds for that unless there is some kind of major problem.

That's why the companies that sell analyzer products also give (sell) training for them as well. It is a complex subject. If it were easy, everyone would already know it.
Classes for one product start a a basics one day, intermediate two day and a three day class.

Of course, now that you know how to use a hammer, you still need to learn how to build a house :-)

The message being that it is one thing to learn how to use the tool and quite another to figure out how to use the information it gives you.



Sent from my iPad using Tapatalk HD

[Ivan Beaver]

Thanks for your input Ivan.  I am a little confused about FFT's.  It seems like most of the online information about them (including an article on this site) is written a little like an advanced tech manual.  The only FFT I currently employ is an iPad app. Audio Tools by Studio Six Digital. The basic multi tool app is only $20, however their digital interface with measurement mic is some $400.  I can plug my measurement mic in via a preamp into the analog input - just not sure if that is very accurate.  Even their own demo does not give a lot of practical info.  Such as - is there a way to tell the difference between  time, phase or accoustical anomalies on the readout?  Just not sure which to use to correct.  Certain anomalies cannot be corrected fully with eq.  I would love to say the church would hire a professional - but unfortunately, most smaller churches are just not going to use limited funds for that unless there is some kind of major problem.

What you need is a DUAL CHANNEL FFT.

A single channel (like the apps on your phone) are a "glorified" RTA.

A dual channel FFT has 2 inputs.  The reference signal (noise or music signal) and the measurement intput (test mic).

It shows the difference between the two signals-whether it is plus or minus.

Without the reference-what you are seeing on your phone is EVERYTHING.  HVAC-cars-people talking etc.  So they can all mess with the measurement.

Of course the dual channel can show MUCH more information-detail etc than a single channel.

[g'bye, Dick Rees]

DUAL CHANNEL FFT.

...doo-dah, doo-dah.

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