Radio Shack SPL Meter

[Andy W.]

How do you use this to EQ your speakers and tune your room? I don't quite understand. Thanks!

 

[bgavin]

You don't. It is not accurate enough. I use mine just to measure SPL levels.

A pink noise generator and analyzer with a measurement-type microphone located at the sweet spot is required for any kind of accuracy.

 

[AudioGaff]

You don't tune your room with eq. You may try to compensate using an eq such as when your trying to flaten out the freq response of a PA system within a room, but fixing problems correctly in your recording or control room has to be done with tools and techniques that are specific to the time domain and not in the frequency domain. Post your problems and questions to the acoustics forum on this site and you'll get some great advice and pointers.

 

[everett]

"but fixing problems correctly in your recording or control room has to be done with tools and techniques that are specific to the time domain and not in the frequency domain".

uhhh?
Don't you mean the other way round - that most tools and techniques, work in the frequency domain not the time domain?
Apart from impulse response measurements, standard measurement techniques utilise fast fourier transforms. The FFT moves the measurement from time into the frequency domain. Without it you couldn't perform accurate acoustic phase and 3D analysis. How do you measure the frequency characterictics of a room without doing a transform into the frequency domain?

 

[everett]

Re. Radio Shack Meter
"You don't. It is not accurate enough"

Hmmm. well that depends on what you're wanting to measure. Accuracy is relative. The RS meter is actually in absolute measurement terms extremely accurate over the lower frequency range. Very flat indeed as are most electret capsule transducers. Seeing that one of the major problems in sorting out room eq is the low end (bass standing waves and so on), then the RS meter is an extremely accurate part of the analytical toolbox.

 

[AudioGaff]

uhhh?
Don't you mean the other way round - that most tools and techniques, work in the frequency domain not the time domain?

No, I got it right. Measurements of time and freq. are the means to identify the problem(s). To fix the problem(s), you use the tools that apply time based techniques that may or may not also be freq dependant to adjust and control absorption, reflection, refraction, diffraction, diffusion, resonance, decay, modes and a few more I'm forgetting.

 

[tonio]

Good question, and I kinda took it over to Acoustics/studio for further investigation.
T

 

[bgavin]

Originally posted by everett:
Seeing that one of the major problems in sorting out room eq is the low end (bass standing waves and so on), then the RS meter is an extremely accurate part of the analytical toolbox.

One frequency at a time.

I use a 1/3 band analyzer and pink noise because I don't want to spend hours measuring and making notations of those measurements. The tool isn't the problem, it's the scope of the tool.