Calibrate your room with a "speaker management" "optimizers" magic box ???

[ONDRAY]

So let's hear it. When should you be using something like a dbx DriveRack to "EQ" your room tone, instead of using acoustic treatment???

To me these things are absolutely useless in a studio environment, especially to calibrate your room's freq. response with.

I recently visited a control room that was using this magic box in a square room, with hard fake wood (plastic) walls and no dampening, traps or diffusers. The guy told me his "dbx" magic box calibrated his room perfectly. So then I heard a mix he did there in my room and to me it was just not translating.

[Glenn Kuras]

This is easy, NEVER!!!

See the quote from Frank that works with me.

You can't fix a time domain problem in the frequency domain.

EQ'ing monitors flat might improve things somewhat but attenuating the room modes works far better.

Think of it this way:

Suppose you're not hearing 90Hz correctly / loud enough because your room dimensions give you a 90Hz reflection that nulls out your 90Hz speaker output right about where your ears are at.

Without any EQ in the monitoring chain, you boost the upper bass going to the MIX until it sounds "right" and then when you listen to your mixes on other systems they sound muddy. Crap!

WITH EQ in the monitoring chain, you try a few 1/3 octave sliders and you find that boosting at around 90Hz seems to help a bit (determined by ear or with a real time analyzer). This is an improvement over no EQ in the monitoring chain because at least you're not EQing your MIX, you're EQing what you're listening to.

BUT - now you have some new problems. Boosting the 90Hz in the monitors not only turns up the direct sound but also causes a stronger 90Hz reflection off the back wall and you still get the same null in your listening position. It's a bit better because you've brought up the overall volume and forced the near field (where you hear mostly direct sound) a bit farther back toward the wall. But you still haven't eliminated that room mode, you're still not hearing the 90Hz accurately, you've limited the headroom on your monitor system, you've boosted other frequencies near 90Hz which have different room mode effects, and the slight benefit you get is lost if you move your head even a foot.

The problem isn't the frequency response of your monitor system (it's probably pretty good already), so changing that isn't a good solution. The problem is the reflections in your room causing standing waves that either cancel or reinforce at various frequencies depending on where you're standing in the room. And those are distance dependant meaning TIME DEPENDANT so your choices are to move the walls and get the time alignment more pleasing (usually not an option) or dampen the walls to reduce the amount of reflected sound.

[ONDRAY]

Yes, thank you. I want some more professional replies so I can have the musician that's recording at this studio show the engineer this thread. I spoke with the musician last night and he says the engineer swears by his dbx "magic box". Figure this is the only way I can get him to see the light.

[Rod Gervais]

Originally Posted by ONDRAY

Yes, thank you. I want some more professional replies so I can have the musician that's recording at this studio show the engineer this thread. I spoke with the musician last night and he says the engineer swears by his dbx "magic box". Figure this is the only way I can get him to see the light.

The problem is that he will still never see the light - perhaps you should have your musician friend record at a real studio - people only see what they want to see - if he can't hear that his mixes do not transllate well in the real world - (and I assume he is a real engineer) then he has already deluded himself to the point that the only thing that could ever convince him is coustomers walking away while letting him know that his mixes suck.

Although - through the use of PEQ you can get a bit of a handle on peaks (around a 6 dB max adjustment) it is PHYSICALLY IMPOSSIBLE to do anthing with a null.

You have a space in a room where there is a sound you can't hear (due to the fact that you are centered in a perfect null) - whether you turn it up - or you turn it down - you can't hear it - how does PEQ change that?

Frank said that you can boost a signal where there is a dip (not a true null) until you can hear the sound at a level you like (and this is only possible depending on the size of the dip) - BUT - that sound is now going to be super heavy in relation to the rest of the mix (in the real world outside of that dip location) which means you are still NOT hearing what is really coming out of your board (hence your recording)

Tis right - You still are not hearing what is coming out of your mix - you are only hearing a modification of the speaker responses in your room. Then you gotta wonder why you spent good money to buy those flat response speakers....

And none of this post (or the previous one) even began pointing out problems related to problems other than modal in nature...... such as early reflections that affect the stereo imagery of the mix - SBIR causing dips at the mixing position due to reflections off the wall BEHIND the speakers....... flutter echo - comb filtering - none of which can be dealt with through PEQ.

It doesn't work - it won't work - it can't work - but some idiots will always buy snake oil from a snake oil salesman because they're cheaper than a real doctor...tutt

Rod

[ONDRAY]

Originally Posted by Rod Gervais

.... Then you gotta wonder why you spent good money to buy those flat response speakers....

The speakers around bad, they're Genelec 8040's too. The mixes don't suck totally, but I guess with time he's adjusted to the real world.

[Ethan Winer]

Originally Posted by ONDRAY

When should you be using something like a dbx DriveRack to "EQ" your room tone, instead of using acoustic treatment???

As you were already told, never. Much more here:

Audyssey Report

--Ethan

[Weasel9992]

...good lord almighty, **especially** not with a DriveRack! It's not meant for the task your friend is putting it to in any way.

Frank