Questions about "indoor EQ"

The Slice

Okay, so I get the idea behind this new method of EQ. It's basically to use the concept of a pressure zone mic. Now, wouldn't that just affect the characteristics of the speaker rather than the room as well, or is that the point? I've perused several threads on EQ and one or more of them talk about just laying the mic on a table or the floor, but aimed at the speaker. Would this apply if the speakers are up on stands so that they are ~ 6 - 7' in the air? Can I rig something so that I can put some sort of flat plate (wood) with the EQ mic up to the speakers, and if so, how large a piece do I need?. I know that putting the speaker on the floor and aimed properly is probably the best option, but the group is using powered speakers, and I can't get them down by myself. Well, I can probably get them down but not back up.

Dra

The point of the "Indoor Method" and the "Outdoor Method" is to measure the speakers response and correct it TO flat. The point of standard AutoEQ is to "correct" the room by altering the speakers response FROM flat.

In all cases the reflected energy (walls, ceiling, floor) is something that the Driverack does not interpret well at all frequencies (particularly below 170 and above 700).
In a room correction, the mic on the floor (or wall or ceiling, the floor is just easier) makes the nearest reflection super fast so it doesn't interfere with the performance of the AutoEQ module.

Hope that clears up your confusion.

DRA

The Slice

Sorry, I must be a little dense but I'm still confused. What is the focus of EQing? Is it to flatten the response of the speakers, or the room? My understanding is that you are EQ'ing the room, which is why the need to EQ in each venue. With that said, I begin to understand that you can't really EQ the speaker to a flat response unless you are doing it in an anechoic chamber where there are no sound reflections and the room acoustics don't play a part. So I guess that what you are saying is that you are EQ'ing to the room, but reducing the sound reflections that the mic is picking up. Now a question. Just how flat does the reflective surface have to be? On one side I have exit doors (double), on the other side, I have windows. There is a frame in the center of 4 panes with hinged pane in that frame. This is all glass and aluminum so the height difference is only 1/4 - 3/8", maybe 1/2" with the exception of the latch mechanism. Now to make another thing clear, do I want to have the mic aimed at the whole speaker, or concentrate on the tweeter?

Dra

You definitely have missed the point. The "INDOOR AUTOEQ METHOD" is a method that Gadget cam up with to avoid having to go outside in rainy / cold weather. He lives in Minnesota. :roll: The outside method (for flattening the speaker natural peaks and dips) was established to mimic the same thing as the anechoic chamber (obviously not that close, but the best we can do without building our own chamber). The results of this AutoEQ session are then transferred (best as possible) to that speaker's output PEQs. Even a complete novice can trial and error the info and finally get to the flattest response possible. From that point, you NEVER adjust the PEQs because they are SET. Now, in any given room the speakers weaknesses do not come into play. Granted a speakers weakness can be a strength or aid in a room, but every room in tweaked with the GEQ (if AutoEQ is used or not) from the baseline of the flat speaker.
In the room to be "EQ'ed" power up one stack only. This helps the process greatly. Place the mic on the floor, on a towel if available, pointing toward the speaker. The mic needs to be in the pattern of the horn, so you may have to be 15 - 30 ft away, depending on elevation and tilt (if any). Personally I like to be about 1/3 to 1/2 of the depth of the audience space.

DRA

The Slice

Okay, that's starting to make a bit more sense. Now, for dealing with the speaker using the indoor method, am I correct that the mic should be both within 1/4" or less of the flat surface (and of course perpendicular to that surface) and that point be within 2 - 3' of the speaker which is aimed at it? Again, I apologize for being so dense about this.

I would like to ask another question here not about DRPA, but about aiming the speakers. Here's my problem. The speakers are at the side of the room essentially in the corners. The option is to move them toward center on either side of the projector screens, but I don't know if the other church group using the system will go for that. The issue is basically this, the more I turn the speakers toward center to avoid sound bouncing off the walls, the more overlap I get in speaker coverage in the center which of course gets worse the farther back I go. The main part of the room is roughly 50' wide by 60' deep. The advice given to "just aim the speakers at the audience" doesn't help a lot. This of course comes from what I've read about the evils of having the sound bouncing off the walls and the problems with the low end resonance which is one of our problems, or overlapping toward the center which invites combing effects which are not desired either. Is the best to experiment with this or is there a specific guideline? I should note that this may be the only option for speaker location as I don't think, as I said, they will go with moving them in towards center, and flying the speakers is definitely out of the question.

Dra

I am not familiar enough with the indoor method to offer any real clarification. Why not just do the outdoors?

Without going to a center cluster you are going to have to compromise the results. I would rather have comb filtering with the speaker aimed on the audience than have incomplete coverage.

The Slice

Okay, so I get the idea. Thanks.

manytalnts

I am trying to understand this as well. There are many discussions about this. The one that seems to be the best is laying the speaker on the floor on it's side. So can someone PLEASE take the time to clarify this if they have tried it as I want to make sure I am clear on this:

1. Lay speaker on it's side.


2. Put mic ON the floor with the mic (on a towel) tip facing the speaker or should it be facing the floor straight down off a stand?
There are a few discussions on this and I am not sure which works out better. 6ft far enough?

3. Should the mic be between the woofer and horn or right at the horn if the mic tip is suppose to face it?

4. I set the volume how loud being that close and indoors? Loud enough to take the reading and hopefully avoid too much reflection back?

5. Should I just do my tops only with this method and then simply adjust / EQ on my subs on the fly?


If I did decide to outdoor is this correct:

1. Place mic on stand facing speakers roughly half way between sub and tops?

2. How far from trees or other should I be behind the mic so as to not get reflection that that mic will notice?

3. Volumes should be at normal playing / concert levels?


Sorry if these are repetitive questions, but I needed to ask them my way so I can understand it.
It would be great if someone made a video showing this. I am a much more hands on / show me how it's done person.

Lastly - Are the presets good from DBX for the speakers they have done or should I just Auto EQ and get the flat response myself?

I'm trying to understand this all before I try it. My DBX PA+ is on it's way as I type this.
I also have the DBX mic - Is there a better one - I would spend up to $400 if it really made THAT much of a difference.

Again ... sorry for any redundancy, I just really want to get this done correctly as I totally understand working with a flat system is MUCH easier to work with and makes EQing a room easier.

Thanks for any and all help -

Brad

Dra

manytalnts wrote:

I am trying to understand this as well. There are many discussions about this. The one that seems to be the best is laying the speaker on the floor on it's side. So can someone PLEASE take the time to clarify this if they have tried it as I want to make sure I am clear on this:
Search - 'indoor", indoor method" indoor auto" etc. You should get some good discussion. I can't really contribute here.
1. Lay speaker on it's side.


2. Put mic ON the floor with the mic (on a towel) tip facing the speaker or should it be facing the floor straight down off a stand?
There are a few discussions on this and I am not sure which works out better. 6ft far enough?

3. Should the mic be between the woofer and horn or right at the horn if the mic tip is suppose to face it?

4. I set the volume how loud being that close and indoors? Loud enough to take the reading and hopefully avoid too much reflection back?

5. Should I just do my tops only with this method and then simply adjust / EQ on my subs on the fly? Yes


If I did decide to outdoor is this correct:

1. Place mic on stand facing speakers roughly half way between sub and tops?just be in the direct radiating field of all components.

2. How far from trees or other should I be behind the mic so as to not get reflection that that mic will notice?As far as possible. Where you are won't affect much, within reason.

3. Volumes should be at normal playing / concert levels? Output at -0- (nothing in the red).


Sorry if these are repetitive questions, but I needed to ask them my way so I can understand it.
It would be great if someone made a video showing this. I am a much more hands on / show me how it's done person.

Lastly - Are the presets good from DBX for the speakers they have done or should I just Auto EQ and get the flat response myself?For passive set-ups, the presets only offer high and low pass filters. The presets are for novices that have no real idea what to do, and frankly... unless you are bi-amping and using JBL speakers it is useless.

I'm trying to understand this all before I try it. My DBX PA+ is on it's way as I type this.
I also have the DBX mic - Is there a better one - I would spend up to $400 if it really made THAT much of a difference.The mic is fine, but yes there are better. Only buy a better mic if you use SMARRT or other high $ system.

Again ... sorry for any redundancy, I just really want to get this done correctly as I totally understand working with a flat system is MUCH easier to work with and makes EQing a room easier.

Thanks for any and all help -

Brad

manytalnts

Thanks Dra -

I really appreciate the reply.

I did find that post, but it wasn't clear enough to me for the indoor method thus the questions.

I do have Smarrt on my Presonus. Is there a mic you recommend by chance?

I think once the PA+ comes in I will just do the outdoor method. Or maybe just try both just to see what the two different settings sound like.

Thanks again!

Dra

Use the search tab above. "earthworks" will bring up several threads discussing several mics.

DRA