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Experiment: Level Matching Frequencies

For fun, from my listening position, I experimented with a Radio Shack SPL meter and a demo disc. Using the ROON equalizer, I level matched frequencies at 80dB (50Hz, 63Hz, 80Hz, 100Hz, 125Hz…etc.) This took a few hours and the results were not good.

Of interest, I corrected a peak of +12dB @ 80Hz, a dip of -8dB @ 100Hz,  and a peak of +6dB between 160-200Hz. Other frequencies up to 10kHz needed minor adjustment of +/- 1 to 3dB.

With adjustments, music sounded terrible. For example it was very thin in the mids, compared to no EQ. This experiment was a waste; I expected and hoped these adjustments would improve the sound. Please note: I am a recreational listener, not and EE nor majored in music which means this experiment was ad hoc and  unscientific.

Have any of you tried this or have thoughts as to why level matching frequencies this way had poor results?

4hannons
elizabeth
6,726 posts
 
Possible problem with your experiment.           
First off, how were you able to adjust the 'Q' of the areas you manipulated? The 'Q' of the actual sound may vary a great deal from the 'Q' of your EQ device! And usually the EQ device is the one failing to have as tight a 'Q' as the real world speaker. So (at least guessing) when you adjusted the  system you were not just dropping the actual peaks, but dragging down a broad range of frequencies nearby.      
That might explain the general leaness of your results.       
One way to alleviate would be boost around the peak instead of dropping the peaks. leave the peaks up, and bring up the rest of the sound. That way you are not as caught by the failure to limit 'Q' as much . (at least I think it might work better)                
(If anyone is confused by what 'Q' is, the Q is the curve of the slope. A tighter Q is a narrower and thinner slope to the peak of the change. A low Q is a broader wider range across the frequency spectrum.Failure to control Q is probably the worst feature of many equalizers.
4hannons's avatar
4hannons OP
166 posts
 

Thanks Elizabeth, forgot to mention that I adjusted the Q as necessary, for example the peak at 80Hz and at 100Hz both had a Q of 1 (very thin slope), the Q at 160-200Hz had a Q of 6 (or 8?) at 185Hz to cover the range.

Quite possible I didn’t have tight enough Q; perhaps I should have used 0.5 Q in the above examples.

Your suggestion of boosting around the peaks might have merit, it’s certainly something I’ll give some thought.

gdnrbob
2,421 posts
 
I am no audio pro, but I recall in my youth buying an equalizer to correct sound imperfections. It, like your experience, was one of disappointment.
One of the problems is that most speakers have crossovers and other such innards that will react, sometimes negatively, to external changes in frequency levels.- I am probably not phrasing this correctly, but I hope you get the idea.
A better way to affect sound deficiencies would be room correction. At least to my simple mind.
Bob
4hannons's avatar
4hannons OP
166 posts
 

Thank you, Bob.

IIRC the EQ function of ROON has received praise for not harming the signal. The more I think about it the more this experiment may become a laypersons journey into optimizing the ROON equalizer.

Can any other  ROON users chime in? Or anyone with experience in EQ? Perhaps this will morph into a  discussion of tips, successes and failures using the EQ function of ROON.

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