RTA Questions

[doncolga]

Hey,

Have any of you all had Auto EQ to just not work at all? I've not used it much on the DEQ 2496 and had a whirl at it this evening outside and to me it just doesn't work as well as my own ears. I thought experimenting with the AutoEQ would be some improvement, but I just didn't hear it. I'm only Auto EQing the tops btw. Mirroring the response on the graphic, than usually 2 bands of pretty wide parametric gets close to what I want. Any suggestions?

Thanks!

Donny

[Grant Bunter]

Hi Donny,

Are you sure the RTA mike is working?

Press "meter" until you get the peak meter, and outdoors, you should see the meter moving due to ambient noise, wind, cars passing by etc.

Not doubting your doing it right, but please run us through step by step, what you're doing to RTA (just in case you've missed something)...

[doncolga]

Yes, it's definitely working. If I have time this week I'll make a video of what it's doing. It just seems like it should get better results than what it does.

Hi Donny,

Are you sure the RTA mike is working?

Press "meter" until you get the peak meter, and outdoors, you should see the meter moving due to ambient noise, wind, cars passing by etc.

Not doubting your doing it right, but please run us through step by step, what you're doing to RTA (just in case you've missed something)...

[40 Hz]

The Behringer manual is lacking in details on how to properly start the RTA process. Luckily I had experience with other RTA's, but I also found a very helpfull pictorial guide somewhere on the internet that made learning the DEQ process a little easier. The description is geared towards home audio, and I don't agree with with everything he says, but his pictures and descriptions are easier to understand than the DEQ's manual. Check it out to see if it helps:

http://www.decdun.me.uk/deq2496.html

What I don't think the manual explains well is that you need to set up your target EQ that you want the RTA to match to. If you don't do that first, I believe the RTA will just match up to whatever you have in your graphic EQ already (???). You can make your target EQ flat, or whatever you want to hear. You need to recall that preset every time before you start the RTA process.

You also need to RTA at the same volume you will be performing at. Your ears hear frequency balances differently at different volumes, and what is flat at a low volume will have a boosted low / high end at high volume.

There is also a button you will see in the RTA process that is labeled ROOM CORRECTION. What I believe that does is push the lows up very slightly, and pull the highs down very sightly. It sound you you are a DJ, and that heavier low-end might be what you are looking for. You could also achieve something similar by setting your target EQ like that (possible boosting the low-end even more is your system is capable). In another thread, Bill suggested I set my system up outdoors, RTA it flat, play prerecorded music through it, adjust the EQ to what I find pleasing to my ear, then save that as the target EQ setting.

For what it is worth, I also have a DBX DriveRack PX, and even when I RTA my system flat with that (even using the same mic in both devices) there is a definite difference between what they both come up with. To put the results in simple terms, the PX typically sounds a bit warmer, and the DEQ typically sounds a bit crisper. After the RTA process, I make a final adjustment by ear, typically taming the peaks / dips slightly to smooth it out a bit. But using the RTA first always gets me very close to what I want, better than I if I just used my ear and didn't RTA at all.

[doncolga]

Wow man that's fantastic. I agree the supplied manual is really lacking. I'm off this week so I should have time time to look over this in detail. I'm very happy with how my rig sounds now, I was just hoping the AutoEQ may make it even better.

The Behringer manual is lacking in details on how to properly start the RTA process. Luckily I had experience with other RTA's, but I also found a very helpfull pictorial guide somewhere on the internet that made learning the DEQ process a little easier. The description is geared towards home audio, and I don't agree with with everything he says, but his pictures and descriptions are easier to understand than the DEQ's manual. Check it out to see if it helps:

http://www.decdun.me.uk/deq2496.html

What I don't think the manual explains well is that you need to set up your target EQ that you want the RTA to match to. If you don't do that first, I believe the RTA will just match up to whatever you have in your graphic EQ already (???). You can make your target EQ flat, or whatever you want to hear. You need to recall that preset every time before you start the RTA process.

You also need to RTA at the same volume you will be performing at. Your ears hear frequency balances differently at different volumes, and what is flat at a low volume will have a boosted low / high end at high volume.

There is also a button you will see in the RTA process that is labeled ROOM CORRECTION. What I believe that does is push the lows up very slightly, and pull the highs down very sightly. It sound you you are a DJ, and that heavier low-end might be what you are looking for. You could also achieve something similar by setting your target EQ like that (possible boosting the low-end even more is your system is capable). In another thread, Bill suggested I set my system up outdoors, RTA it flat, play prerecorded music through it, adjust the EQ to what I find pleasing to my ear, then save that as the target EQ setting.

For what it is worth, I also have a DBX DriveRack PX, and even when I RTA my system flat with that (even using the same mic in both devices) there is a definite difference between what they both come up with. To put the results in simple terms, the PX typically sounds a bit warmer, and the DEQ typically sounds a bit crisper. After the RTA process, I make a final adjustment by ear, typically taming the peaks / dips slightly to smooth it out a bit. But using the RTA first always gets me very close to what I want, better than I if I just used my ear and didn't RTA at all.

[Grant Bunter]

The DEQ will tell you if the pink noise level isn't loud enough to overcome ambient noise.

I don't agree that you need to RTA to the same level as which you will play.
Otherwise you couldn't turn up (or down) as that would infer your EQ would be out...

[40 Hz]

The DEQ will tell you if the pink noise level isn't loud enough to overcome ambient noise.

I don't agree that you need to RTA to the same level as which you will play.
Otherwise you couldn't turn up (or down) as that would infer your EQ would be out...

You definitely need to be close to the same volume or else you are not getting an accurate response. If you RTA @ 80 dB and perform @ 110 dB, your system will no longer be truly flat.

From the DBX DriveRack manual:

"Turn the Data Wheel until pink noise is playing through your speakers at performance level."

It is due to the Fletcher-Munson Curve / Equal Loudness Contour. That is why home stereo's ofter have a LOUDNESS button (it compensates for the fact that you ear hears mid-range tones more prominently at lower volumes. The curve flattens out as volume increase, but it is still in effect.

Check out: http://www.webervst.com/fm.htm

But in reality, RTA'ing at a lower volume and then cranking it up may appeal to some people. It will be the equivalent of dipping the mid-range slightly. In the end, EQ your system to whatever sounds best to your ears, regardless of the RTA results.

[Bill Fitzmaurice]

It is due to the Fletcher-Munson Curve / Equal Loudness Contour.

Our hearing is subject to Equal Loudness, but a microphone isn't. When doing an auto-eq the level need only be high enough to effectively mask any ambient noise.
Agreed the Behringer manual sucks. You must give the RTA a target curve, be it flat, smiley-faced or whatever. If you don't give it a new target it simply sets it again to what's already there, so there's no wonder that it doesn't sound different.

[40 Hz]

Our hearing is subject to Equal Loudness, but a microphone isn't.

Hummm, I have been blasting pink noise at full volume and making quite a nuisance of myself for far too long (as I thought it was more accurate). HaHaHa!!!

I am still trying to wrap my mind around the fact that a microphone is not affected by Equal Loudness, but that makes sense. But then, unless the pink noise is weighted somehow, a RTA would only be truly accurate at a specific SPL????? The Equal Loudness concept does come into play as you adjust your system volume, so I can't see anyway an RTA can avoid this effect.

I never EQ my systems flat anyway, so I guess it's just theoretical - but I like to fully understand what I am doing.

[Bill Fitzmaurice]

I am still trying to wrap my mind around the fact that a microphone is not affected by Equal Loudness, but that makes sense. But then, unless the pink noise is weighted somehow, a RTA would only be truly accurate at a specific SPL?

If you play pink noise through your system and watch it on your RTA display it will appear the same irrespective of the level. What changes with level is how you hear it. For that reason you may add more bottom and high end at low playback levels, and reduce the low and high end at high levels. That's what loudness controls did way back when, and what dynamic EQ does today.

[doncolga]

If I didn't want to use AutoEQ, couldn't I just play pink noise then adjust my EQ until the RTA shows the response curve I'm aiming for?..I'm guessing that should be a gentle slope down from left to right?..isn't that how older RTA's worked?

[Bill Fitzmaurice]

If I didn't want to use AutoEQ, couldn't I just play pink noise then adjust my EQ until the RTA shows the response curve I'm aiming for?

Yep, but it takes ten times longer for you to do it that way.

[WB]

If I didn't want to use AutoEQ, couldn't I just play pink noise then adjust my EQ until the RTA shows the response curve I'm aiming for?..I'm guessing that should be a gentle slope down from left to right?..isn't that how older RTA's worked?

I've done it both ways and agree with Bill that it takes ten times longer.

[WB]

There is also a button you will see in the RTA process that is labeled ROOM CORRECTION. What I believe that does is push the lows up very slightly, and pull the highs down very sightly.

The ROOM CORRECTION button doesn't get mentioned much, but I've always preferred the results with it on. It basically drops the SPL by 1 dB per octave (from low to high) if I remember the manual correctly.

Also, the results will vary depending on how much lows you let the AutoEQ correct. I've always preferred not to let too much low end in.