Fixing Early Reflections off console

[Jens Eklund]

Monitor & Mixing Desk Placement - Reflection Issues

Originally Posted by Jens Eklund

Assuming all early reflections from nearby walls/ceiling have been dealt with; increasing the distance between the speaker and desk, raising the speakers (and if so, a slight tilt so the acoustic axis is still pointing towards the ears), minimizing the desk size and also tilting it, redirecting the reflection away from head height, are some measures one can do to minimize these early reflections.

[rjay]

Thanks but that thread is just full of name-calling and virtually no practical info ...

[Jens Eklund]

Use the ETC to identify possible issues and to confirm if possible treatment/solutions work or not.

[rjay]

I spotted the ER problem by ear, though I do use REW which has an ETC chart. The problem is I don't know how to interpret it - for one, I don't know what a "good" ETC should look like.

[rjay]

Here is my ETC ...

[Demor]

Originally Posted by rjay

I spotted the ER problem by ear, though I do use REW which has an ETC chart. The problem is I don't know how to interpret it - for one, I don't know what a "good" ETC should look like.

Well, you should get rid of those 4 peaks. Can't see what the time is in the graph because the scale is a bit large. Zoom in on the region up to 28 ms.

[rjay]

Originally Posted by Demor

Well, you should get rid of those 4 peaks. Can't see what the time is in the graph because the scale is a bit large. Zoom in on the region up to 28 ms.

Yes, I figured that much !

But so far, the only way I've managed to remove them is by placing a blanket over the console ... not exactly a viable solution.

[rjay]

Zoomed in a bit - does this explain any more ?

[Demor]

The last two/three peaks are not very high in volume and meters away so that can't be the desk... so...... could you zoom in further to see below 10 ms?

[rjay]

Oh, interesting. How about this ?

[rjay]

or this ?

[Demor]

The first "glob" at 1-2 ms is probably the desk and the one at 4 ms might be, that one is about 1,3 meters longer than the direct signal from the monitors. Can you move the speakers a bit further away from the desk? This might get the reflections to pass by you below ear level.

[rjay]

Thanks a lot Demor. Tomorrow, when I'm in the studio again, I'll push the speakers back a bit but then they'll be closer to the wall (currently 14inches away) so it's a balancing act.

Is it possible for you to guess how much I'd need to move the speakers back - we're talking a couple of inches are we ?

And you're saying that there is another reflection 1.3metres from the speaker ?

[OpusOfTrolls]

You might be able to angle the entire console by raising the back of the legs. This should be considered carefully because of the weight.

[rjay]

Originally Posted by OpusOfTrolls

You might be able to angle the entire console by raising the back of the legs. This should be considered carefully because of the weight.

No, unfortunately not, it weighs a ton

[DanDan]

Try reversing the phase of one speaker. Play Pink Noise. Listen for a null at the acoustic centre. It can be helpful to block one ear and listen with the other. The null is usually very precisely placed. It may not be where you expect it geometrically. If you have desk reflections causing problems, they can be seen as spikes on the ETC or quite vivid comb filtering. Chose your view. Either way the problem is fairly easily diminished by moving the speakers or angling the desk.
Desktop Reflection Revealed
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[OpusOfTrolls]

Originally Posted by rjay

No, unfortunately not, it weighs a ton

This doesn't mean it can't be done, it's just more complicated.

[DanDan]

Genelec Community - Tech Tips

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