Speaker correction with free Room EQ plug-in for Foobar2000

[manniraj]

@Santy,

I think I agree that the microphone plays the big role here as I can see that when I placed the microphone on my cushion the right channel was not getting detected and I was continuously message that the microphone is not being detected. So I placed the microphone over a carton box at the ear level on my sofa where I sit. I think my Yamaha receivers microphone is good and sensitive enough as I got very good results using the same for HT measurements/settings on the Energy RC Micro speakers.

 

[Thad E Ginathom]

I suppose room messes up only with the frequency response. What we hear. Not what is played.
Whereas a poor DSP could spoil every other quality of the sound... dynamics/ depth/ resolution/ soundstaging/ imaging / transients or whatever you use to define sound. Sadly though these are not seen on measurements.

Yes, point taken: if the sound doesn't leave the speaker at all, then it certainly is not going to reach the ear.

What manniraj is reporting, though, sounds like a big win, with undoubtedly improved quality.

Yes, all depends on the microphone, and if one is really serious, I think there are specialist products for the purpose.

They tell us, of course, that we should correct the room acoustics first.

 

[Santy]

Tripod was doing its mic positioning job for atleast 15 measurements.

Initial impressions of A/B (original/ adjusted):
It does work. No doubt. I can't say if it improves the sound. Quite early to suggest.

In my case, its a direct attack on the mid range. The plugin says it is enhanced and asks me how much it should be toned it down. I am not comfortable with fiddling in that range. Honestly. Because that is where quite a lot of music lies. May be my speakers are too honest in that range. I was expecting some disproportion in the 200hz range. Check the graphs:

The male vocals are taking a bit hit with the adjustments. So after a quick A/Bing, I seem to be liking the untouched sound more. May be I adjusted the slider too much, cutting down more of the 'necessary' frequencies. The neutral reference setting simply robs away the smooth highs (check manniraj's graphs). Neutral doesn't certainly mean rolled off highs as the plugin tries to achieve.

Will have to do a serious testing sometime later as I did everything in a hurry.

One thing is clear. It doesn't truly neutralize. It reduces the enhanced frequencies as per the settings, but does not compensate for the subdued frequencies. So its only a half baked attempt of room correction, IMHO.

It is also possible to see that MathAudio Room EQ doesn't boost the spectral components lying below the dashed line. This important feature prevents the large excursions of the speaker diaphragm that can be caused by the ideal linearization of the frequency response. Besides that this feature allows you to avoid the overcompensation of your room.

 

[manoj.p]

My experience on the microphones.

None of the microphone is flat. All have peaks and dips throughout its frequency range. Not only that, they are not as much sensitive towards low frequencies which is what matters the most for equalization. If you are using laptop mic, headset mics, phone mic etc, only god can help you. It might be good to play with software etc but to actually using it for processing the music is bad idea. It can only make it worse.

Second thing is using the AVR / Auto eq microphones. These are better quality but again not flat. The manufacturer's usually test lots of these and come out with the average calibration curve. This calibration curve is fed into the AVR software and then it becomes useful to that particular AVR. Since we don't actually have the calibration data to it, if you use it still, you are mostly equalizing the mic output, not the room output.

If one is serious about measurement, better to buy EMM-6 or UMM-6 from part-express.com. It runs about $50 shipped in US with calibration data. Cross-spectrum Cross

 

[manoj.p]

One thing is clear. It doesn't truly neutralize. It reduces the enhanced frequencies as per the settings, but does not compensate for the subdued frequencies. So its only a half baked attempt of room correction, IMHO.

Santy,

Your observation is right. Most auto eq systems, including the pro-ones do not boost the frequencies due to the fear of amp burnout/amp compression. Trinnov does like max 6 db boost. They can bring down some frequencies, no problem there. Similar is the case with other eq system. If you are doing manual eq and are sure that your amp has some steam left, you can boost more. When I was equalizing my subs, I knew my amps can take it, so I had added a boost of 12db at one frequency.

Also what looks like dip to us could be null. Like the one dip near 40 hz in your graph. If the dip is symmetrical on both sides and quite sharp, then its most likely a null and can be seen if you increase the resolution. A null cannot be compensated for so the eq system just ignores it.

 

[Thad E Ginathom]

One thing is clear. It doesn't truly neutralize. It reduces the enhanced frequencies as per the settings, but does not compensate for the subdued frequencies. So its only a half baked attempt of room correction, IMHO.

Was wondering about that, as I looked at your graphs. It cut's, but it does not boost?

I think maybe the calibration thing for mics is a big part of the specialist product thing that I was thinking of.

 

[mmm]

Was wondering about that, as I looked at your graphs. It cut's, but it does not boost?

The 'cut-only' method of equalization prevents clipping. Clipping is a sort of audio distortion. The sound can be clipped if the waveform exceeds its maximum level. Any boost can produce clipping because it increases the amplitude of the waveform. The 'cut-only' method doesn't increase the amplitude of the waveform and consequently ensures the absence of clipping.
Citation from Wikipedia: http://en.wikipedia.org/wiki/Clipping_(signal_processing)
"Because the clipped waveform has more area underneath it than the smaller unclipped waveform, the amplifier produces more power than its rated (sine wave) output when it is clipping. This extra power can damage any part of the loudspeaker, including the woofer, or the tweeter, by causing over-excursion, or by overheating the voice coil. It may cause damage to the amplifier's power supply or simply blow a fuse.
In the frequency domain, clipping produces strong harmonics in the high frequency range (as the clipped waveform comes closer to a squarewave)."

 

[Thad E Ginathom]

Ah, yes... I should have thought of that!

Thanks!

 

[spirovious]

Not for foobar,but another option-
Equalizer APO / Documentation Wiki / Documentation