1 Topic by nsg

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Topic: High-pass filters and the gain-sharing auto-mixer

We are planning to make two changes to the gain-sharing auto-mixer, one of which will affect the high-pass filters as well:

1. Include a frequency control for each channel on the Gain-Sharing Auto-Mixer's control page. This will adjust the high-pass filter's corner frequency, if the option of using a high-pass filter is selected in Device Properties.

2. Set the high-pass filter's corner frequency to a default frequency of 80Hz. This affects both the regular high-pass filter and the version included in the gain-sharing auto-mixer.

Does anyone have any comments on this?  Is 80Hz the appropriate default frequency?  Thanks!

2 Reply by JoshM

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Re: High-pass filters and the gain-sharing auto-mixer

1. It seems to me that providing the high-pass controls in the Gain-Sharing Automixer's control page is a great idea.

2. I am not so sure it is a good idea to adjust the high-pass filter's native default frequency to such a low setting. I kind of like the idea of it coming out of the box at a frequency that is normally higher than where it will be used. However, having both the high-pass filter and the low pass filter set to the same frequency isn't the brightest thing to do. Personally, I would prefer the high pass filter to come out of the box and default to a 500Hz setting while having the low pass filter come out of the box with a default of 1000Hz to 1500Hz. This way when you toss one of each in the same signal path in a project and apply signal, you WILL get some sort of output (which you do not currently get). Then, by hearing the extremely bandwidth limited frequency response it is quite obvious that you need to adjust the settings.

While we are talking about adjusting the default behavior of devices, I think it would be nice if a mixer would default to all the crosspoints at minimum rather than the current behavior where some are turned up. However, I know this would be a drastic change since the mixers have behaved this way since the inception of MediaMatrix.

Josh Millward
Burnt Orange Studios

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3 Reply by cwa

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Re: High-pass filters and the gain-sharing auto-mixer

This issue with the low pass filter defaulting to 500hz is that that is too high for the automatic mixer.  In the automatic mixer, the low pass is used for filtering out rumble  You don't want it to affect the voice band.  Currently, there is no way to have a different default value for the low pass by itself, verses as it is used in the automatic mixer.  Since using the high pass as a rumble filter is a common use, it seems that 80hz is a reasonable setting.

As for the mixer defaults, I tend to agree with you.  We can change this if it makes sense to others.  Comments anyone?

Note that these defaults only affect how the device is originally created when it is dragged into a design.  Existing designs are not affected.  Thus, we can changes these at will. 

Are there any other device changes people would like to see?

4 Reply by JoshM

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Re: High-pass filters and the gain-sharing auto-mixer

cwa wrote:

Currently, there is no way to have a different default value for the low pass by itself, verses as it is used in the automatic mixer.

Thanks for clarifying this, Charles. For some reason, I thought that it is possible to dictate what you want the default value to be when you add that filter to the device. I thought I had seen some device somewhere that does something like this... but of course I can't put my finger on it right at this moment. How convenient...

I was thinking of something like when you check the box, it not only tells the device to add and wire in high pass filters, but also to set them at a value of 80Hz to 150Hz.

Personally, I think 80Hz is too low anyway, but I know that we could all have a very long discussion as to exactly what frequency it should be. Personally, I would be aiming for something more in the 120Hz to 150Hz range. But like I mentioned above, it's all about the personal taste of the designer anyway.

Josh Millward
Burnt Orange Studios

JoshM's Website

5 Reply by ivorr

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Re: High-pass filters and the gain-sharing auto-mixer

I feel that as long as the high-pass filter controls are visible in the automixer device we don't need to change any defaults. I see the point of the default 800Hz value, it's a common place to start on a 2-way crossover. Also easy on compression drivers if you forget to set the frequency before deploying.

The only true wisdom is in knowing you know nothing. -Socrates

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6 Reply by Mat

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Re: High-pass filters and the gain-sharing auto-mixer

This has now been fixed for the next release of NWare.

Mat's Website

7 Reply by phils

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Re: High-pass filters and the gain-sharing auto-mixer

Here from the other thread...
So what was the final decision on default settings for the HPF and LPF?
All the arguments back and forth have validity; who was brave enough to make the call?

"The single biggest problem in communication is the illusion that it has taken place."
                                                                                        - George Bernard Shaw

8 Reply by cwa

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Re: High-pass filters and the gain-sharing auto-mixer

Unless there is any objection, we will leave the HPF default at 800hz, and do the work so we can have a 80hz HPF in the Automixer (and we will add a control so this can be adjusted).