EQ Does Improve Bass Decay

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EQ Does Improve Bass Decay


I wanted to share some examples of how EQ does reduce ringing in the bass, or rather, improves bass decay. Why? Because it's minimum phase and it must. I'm including both simulations of the EQ effect, as generated in REW, as well as an actual measurement using DIRAC (which is still EQ, even if it's very special EQ). It shows that EQ does improve bass decay. This comes up a lot and I wanted to provide some solid results to make the point.

First, a few animations to show a comparison of the waterfall (what most are used to seeing). This is an actual speaker measurement but showing the simulated effect on the waterfall when EQ is applied to flatten the response.

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Here is a similar animation showing what DIRAC did as compared to the No EQ result. This is not a simulation but a real-world measurement.

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However this may only be somewhat interesting, as many might suggest that cutting the peak lowers the level of the peak, but decay is a slope not a level, so what effect does it have on the slope? Well, look for yourself. These are comparison of the impulse response filtered at 63hz (1/3 octave) which was around where a large peak in the untreated response showed up.

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Look at the slope of that black line.

Here is the same information as above, but using just PEQ and not DIRAC.

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And finally an overlay to show just how seriously it impacted decay. Look at the tail.

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And again, same information as above, but using PEQ

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EQ clearly improves bass decay and does so far better than reasonable bass traps could achieve at such low frequencies. That isn't to say that LF damping is not important in a room, but my view is you need both. Now keep in mind that in general EQ will not provide identical results (and thus identical improvement in bass decay) at different positions in the room. That is why multiple low frequency sources (i.e. subwoofers) and some bass trapping is still needed.
 
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Sledge

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DanDan - I really don't wan to poison anything, as you wrote, even if I pointed out in my first post that decay of the main peak at 120 Hz on the very first picture remains exactly the same after EQing as before (contrary to the title saying that it does change). This my argument was simply ignored - you can check the picture it if you want. But nevermind, I cant read the waterfalls.

I asked you a simple question about your concept of the feedback from the room to the loudspeaker. The loudspeaker system ended by the movement of the cone or if we go more to the "room", by the SPL in the close field of the cone. So, if there shall be any feedback from the room, I mean feedback in its meaning from controlled systems, there should be a change in the movement of the cone or close field SPL, signifficant for the observation, when the loudspeaker is placed into the room, right? Have you any argument/measurement that spport this concept of feedback?
 

DanDan

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Sledge "I pointed out in my first post that decay of the main peak at 120 Hz on the very first picture remains exactly the same after EQing"

I cannot imagine what you are seeing or how you interpret it, but that is just simply utterly the opposite to what is on the picture. In the first picture, a predicted response btw, the level of the 120Hz mode is reduced dramatically and the slope of the decay is increased. In the second picture Dirac flattens it. Sledge, since your first post here you have been saying ' I don't think so....... I doubt it...... Prove it...... You jump from one random daft claim or misunderstanding to the next. You have contributed nothing here.

Matthew, we need to do something here. Your OP does what it says on the tin, but it is drawing these crazy hostile lack of faith based responses.
I am concluding that the work would be best preserved as a reference item. Including the helpful and interesting responses near the start.
 
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