Haas Kicker--I want one! (?)

[RKrizman]

Or do I? Can anyone give a good layman's explanation of what this is? From another thread I gather it's a way of bouncing a strong first reflection back to the listening position from the rear wall. Is there a minimum or maximum distance required? What exactly is the point of this?

I know Andre has posted that these are of minimal usefulness, but nonetheless, who wouldn't want to "kick some Haas" in their studio?

It sounds like I'm just kidding around, but I really do want to understand this.

Thanks,
-R

[SAC]

Its an acoustic response and part of an overall acoustic model - not something you buy or install.

And the optimal way of providing it is with a QRD/PRD as part of an overall response model. Not simply as a separate 'add on'.

And in order to do this, one would benefit in understanding the acoustic model and the various interactive aspects it entails.

[PaulP]

Here's an except from Floyd Toole's book on the matter : Haas effect.

Click the upper box on the right to open up the page.

Paul P

[SAC]

Simply go to Sound System Engineering by Davis and Davis, 2nd ed. or Davis & Patronis 3rd ed.

They put the entire system together. Focusing simply on one attribute of the system is like trying to evaluate a car by simply listening to the radio.

As time permits - meaning after taxes are wrapped up! We will try to post more specific info on the criteria for such a room, and the principles that each aspect touches.

Once you get the various issues being addressed, and then the primary tools used to achieve them, I think the entire integrated concept - along with each of the various techniques and tools - will become rather straightforward.

[RKrizman]

Wow, great article. I look forward to digging into this stuff.

Here's my understanding of the Haas kicker. The idea is that by reflecting sound from the back wall to the listening position in a small room the difference between that and the direct sound to the listener from the speakers will be less than 20 ms. The result would be a precedence effect that, because the reflected sound is delayed, will make the image seem to come more strongly from the speakers in front of the listener. Is this more or less correct?

-R

[RKrizman]

Originally Posted by SAC

Its an acoustic response and part of an overall acoustic model - not something you buy or install.

In another thread Lupo was identifying his Haas kickers mounted on the back wall. I realize the effectiveness will relate to an overall plan, but it is a physical thing isn't it?

-R

[RKrizman]

So is the point to reflect the initial signal from the back wall to the listening position in order to allow the precedence effect to strengthen the sense that the image is coming from the front?

If that's it, I'd guess that it would only be useful in a smaller room, where the time difference between the two signals is less than 20 ms.

What about the accompanying comb filtering?

-R

[PaulP]

Originally Posted by RKrizman

So is the point to reflect the initial signal from the back wall to the listening position in order to allow the precedence effect to strengthen the sense that the image is coming from the front?

The point as I understand it is to make the room sound bigger than it is.
Reflections that are earlier than some threshold (20ms often mentioned)
have less effect and later ones cause an echo. The kicker is a mechanism
to emphasize the effect, to make sure we've noticed.

The rear wall is often mentioned only because it's usually the only surface
you have a chance of getting a reflection from with sufficient delay, all other
surfaces of the room are too close. If you could take the reflections from
the rear wall and bounce them around the room a bit you could generate
some additional spaciousness but the level of the reflections drops so much
that it's probably not worth it.

Paul P

[PaulP]

Originally Posted by RKrizman

What about the accompanying comb filtering?

We like comb filtering. It's what tells us we're not outside or in an anechoic chamber.

Paul P

[RKrizman]

Originally Posted by PaulP

We like comb filtering. It's what tells us we're not outside or in an anechoic chamber.

Paul P

Yes, but if it's all coming from one source the comb filtering will be more ringing and less broadband, right? Objectionable in the same way console or side wall reflections are. Or why not?

-R

[jayfrigo]

As discussed in the other LEDE/Haas thread, an even decay of diffuse reflections post-RFZ winfow is preferable to the specular ones. Comb filtering is detrimental until it becomes so complex (multiple reflections diffused spatially and temporally) as to become "ambience" rather than a recognizable interference pattern.