Setting the Master EQ to compensate for the room

[Lefty]

I've been wanting to find a way to set the Master EQ on my SX900 to compensate for the speakers, and any acoustic shortcomings of the room I have it set up in. (And to set up a subwoofer in the future)

I found an app for the iPhone/iPad called Housecurve. I spent $6 on the app, and played with it for a couple of hours to  learn it well enough to create a filter suggestion. 

I set the app up with bluetooth to my keyboard, then had it play its audio "sweep" through the speakers in my SX.  The app "listens" to what the speakers put out.  I set it to create 8 filters since the SX900 has 8 filters available in the Master EQ window.  The app creates a file to view and input manually on your keyboard.  For the keyboard in my music room app suggests:

  FREQ   GAIN     Q
   83    -7.0   9.6
  123    -7.2   4.6
  216     5.5   6.6
  375     4.5   6.6
  416    10     2.9
  757    -5.6   5.2
1503    -5.1   6.9
2263     4.8   6.4


Your rooms will have different values than mine obviously.  As you can see from the gain values, my room is untreated.  The high gain values indicate large peaks or dips that have to be corrected.

I can also see from the app that my keyboard would benefit from a subwoofer, as there is very little bass below 60HZ, and what there is isn't correctable with the Master EQ.

Craig

P.S.
Some shortcomings with my method.

1. Because the "test" sound is sent via bluetooth to the keyboard, I think any master EQ settings are bypassed.  Because of this, I'm unable to get a before and after set of readings.  I think maybe if I import the audio though....
2. The software uses a compensation file for the built-in microphone on the iPhone, but it isn't a calibrated mike.  I think the app supports a calibrated mike that's about $80.

[Dnj]

Try these  EQ/CMP settings they work very well for my SX900....

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[BogdanH]

hello Craig,
I don't know HouseCurve app, but from what you wrote ("For the keyboard in my music room app suggests.."), I think you interpret the data wrong. I say that, because I can hardly believe that one would need to reduce low frequencies for keyboard built-in speakers. That would actually mean that you have too much bass, which is very unlikely. And then, I see no adjustments above 3kHz in your chart.
It's just my opinion, but the whole chart looks weird to me. Let me explain what I mean...
At 416Hz you are supposed to increase gain by 10dB and use Q=2.9. Because Q is small, it will affect quite wide frequency range below and above 416Hz -including 757Hz (which in next step, you're supposed to decrease by -5.6dB).
In short, we can't linearize that big fluctuations in such narrow frequency range. Usually we adjust frequency at every octave, or every 2nd octave, i.e. 50Hz, 100Hz, 200Hz, 500Hz, 1000Hz, 2000Hz, 4000Hz and 8000Hz -that covers full audio range.
If we now set gain at 1000Hz and set Q to zero, it will affect all frequencies between 500Hz and 2000Hz (by assuming equalizer does it's job properly). But how do we correct for example 750Hz in this case? We can't do that directly -to do that we would need parametric equalizer. But we can manipulate settings at 500Hz and 1000Hz and this will also affect 750Hz. There will always be small fluctuations.. the idea is to get average flat response.

My additional thought... I think it's not worth to bother making precise EQ adjustments with built-in speakers. Main reason being: they're directed upwards and so we're loosing mid/high frequencies anyway (unless you're listening just above keyboard). What I'm saying is, just set EQ so it sounds to your liking.

Bogdan

[overover]

... But how do we correct for example 750Hz in this case? We can't do that directly -to do that we would need parametric equalizer. ...

Please note that the Master EQ (MEQ) mid bands on PSR-S/SX/Tyros models and Genos are fully parametric, i.e. we can set not only the Q factor (and thus the bandwidth) but also the center frequency for each band (in reasonable steps). The bottom and top MEQ bands have a shelving characteristic, so there is no Q setting here, but the frequency can of course still be adjusted. In principle, these two outer MEQ bands work like the bass and treble controls of a standard two-band tone control, with the only difference being that the cutoff frequencies (from which all frequencies below/above are boosted or cut) are adjustable.

By the way, I recommend setting the highest MEQ band to a higher frequency (around 10 - 12 kHz). So you can raise the treble better if necessary.

Basically, I recommend starting with the "FLAT" setting for the MEQ setting. (If you already like one of the other MEQ presets, you can of course also use this as a basis.) First, I would (while playing different preset styles and their OTS) adjust the bottom and top MEQ bands, i.e. bass and treble . Then you go "from the outside in". When boosting a frequency band (positive Gain) I recommend a relatively large bandwidth, i.e. a small Q value. In contrast, for lowering a certain (interfering) frequency, a relatively narrow bandwidth should be used, i.e. a large Q value. I usually do this by first set a boost (e.g. +6dB) for a specific frequency band and then adjusting the center frequency until the disturbing frequency becomes LOUDER. Then this frequency band can be lowered (e.g. -3 dB) to filter out the interfering frequency.


Best regards,
Chris

[BogdanH]

hi Chris ..and I learned something today.
Honestly, because I just use Flat setting, I didn't know EQ is parametric -thank you for pointing that out!

Bogdan

[Lefty]

Hi Bogdan.  I'm sure it would help if you could see the chart.  It would be pretty hard to interpret the data wrong, as it outputs the parametric settings it recommends.  The settings it recommends are based on the target curve, (I chose B&K), and the number of filters you have available.  When I look at the recommendations the app made versus the chart, these settings look spot on except for a mistake I made, which OverOver explains.

OverOver.  Thanks for explaining that the first and last setting in global EQ are for shelving.  That now makes perfect sense.  So I need to redo my test using 6 filters, and then set any shelving. According to the current chart, I need to increase the bass shelving below 63hz, and reduce the treble a bit above 4K.

The Housecurve app is reasonably easy to use, and the results are objective, not subjective.  I like that.

Craig