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[Matt Greiner]

Question all, I've been trying to wrap my head about this and can't figure it out. 

If you run aux fed subs, how can you get your set break music to sound right?  I'm sending the kick to my subs for the show, but then, for the break music, I can't just send that channel to the subs, as I will not get any of the full range.  And if I send that channel to L/R, I won't get any low end.  Is there something simple I'm missing?  I'm using a Midas M32. 

Side note, the last arena show I went to they were using a Midas Pro 2, and I saw the engineer adjust what I think was the low pass filter during the break music and heard the subs level go up, but I could be wrong.  (I didn't have the best view as I standing off to the side of FOH.)  Maybe they weren't using aux subs though.  I am just trying to learn how to get a great sound for the live show, but still have decent sounding break music without having to constantly adjust the EQ for break music.

[William Schnake]

Question all, I've been trying to wrap my head about this and can't figure it out. 

If you run aux fed subs, how can you get your set break music to sound right?  I'm sending the kick to my subs for the show, but then, for the break music, I can't just send that channel to the subs, as I will not get any of the full range.  And if I send that channel to L/R, I won't get any low end.  Is there something simple I'm missing?  I'm using a Midas M32. 

Side note, the last arena show I went to they were using a Midas Pro 2, and I saw the engineer adjust what I think was the low pass filter during the break music and heard the subs level go up, but I could be wrong.  (I didn't have the best view as I standing off to the side of FOH.)  Maybe they weren't using aux subs though.  I am just trying to learn how to get a great sound for the live show, but still have decent sounding break music without having to constantly adjust the EQ for break music.

Matt, we run our subs on an aux and have for a decade at least maybe longer.  We run our computer into two channel on whatever mixer we are using and then turn up the aux that feeds the subs on those two channels.  You have to make sure you don't mute the Aux Master going to the sub and that the main L/R are turned-up, but besides that there is no magic here.

Let me know if I misunderstood your questions.

Bill

[Dave Garoutte]

Somewhere in the signal path to the subs is a low pass filter that attenuates the highs, so feeding the aux channel a full range signal is fine.

[Mike Caldwell]

For just about every aux fed sub application all the inputs are sent/mixed to the tops/ low mid high boxes and the inputs that need some sub action like your kick drum also have the aux/mix brought up on that input channel that feeds the subs.

From the wording in your first post it almost makes me think that your kick drum input is only going to the subs and not into the top boxes.
You would treat the inputs for the break music just as any input needing some sub, bring up the sub aux and mix in the subwoofer to the needed level.

[Matt Greiner]

From the wording in your first post it almost makes me think that your kick drum input is only going to the subs and not into the top boxes.
You would treat the inputs for the break music just as any input needing some sub, bring up the sub aux and mix in the subwoofer to the needed level.

That is correct, that is what I was thinking that it was a "main L/R or aux subs, not both."  Now, as I read your response out and reread my post out loud, I realize that it is exactly as it sounds, it's an "aux."  The signal is sent to both L/R and the aux sub buss.  Any aux is not either or, they are separate from each other.

The way I was planning to implement this is as follows, please correct me if my thought process is incorrect.

On my M32, I would go to the EQ section of my main L/R, set a High Pass filter (Linkwitz-Riley 24) at 110 Hz (this is where the manufacturer recommends me to set the crossover in my DSP, so I would mirror it on the console).  I would then go to my aux sub buss, and set a low pass filter at 110 Hz, same L/R 24 filter.  Then I would just have to assign my input of break music to be on both the L/R and aux buss.

In my DSP, I already have it set up so anything 110 Hz or less gets filtered out of the top boxes, so it doesn't matter if the kick is sent to the tops.  Which is what Dave said, just using the low end as the example.

I would guess I could do the same with the DSP I already have, but it would require an additional cable to each DSP.  If I do this in the M32, I am essentially doubling up on my DSP's in the signal chain.

[Mac Kerr]

I would guess I could do the same with the DSP I already have, but it would require an additional cable to each DSP.  If I do this in the M32, I am essentially doubling up on my DSP's in the signal chain.

Not something you want to do.

Mac

[Matt Greiner]

Not something you want to do.

Mac

What would be the harm?  Isn't it essentially just like adding EQ to other channels?

[Mac Kerr]

What would be the harm?  Isn't it essentially just like adding EQ to other channels?

If your system already has the proper crossovers you do not need to add more on top of them. It will change the expected tonality as well as the phase response.

With aux fed subs you don't want to add any more high pass to the mains than is already in the system. If you have no processing on the subs you can low pass the subs. Feed the mains from the main out or matrix out you usually do, feed the subs from an au bus that has added to it all the channels you want to go to the subs. This could be low drums, bass, keys, playback, or any other input that can use the extended low end. Exclude from the subs those things that don't need the low end, vocals, most horns, guitars, strings. Use your discretion.

Mac

[Matt Greiner]

If your system already has the proper crossovers you do not need to add more on top of them. It will change the expected tonality as well as the phase response.

With aux fed subs you don't want to add any more high pass to the mains than is already in the system. If you have no processing on the subs you can low pass the subs. Feed the mains from the main out or matrix out you usually do, feed the subs from an au bus that has added to it all the channels you want to go to the subs. This could be low drums, bass, keys, playback, or any other input that can use the extended low end. Exclude from the subs those things that don't need the low end, vocals, most horns, guitars, strings. Use your discretion.

Mac

I understand what you mean about not wanting to add any additional high pass to the mains, and I do have processing already on the subs.

I guess the only option then would be to change the DSP output settings, and run a separate signal out just to the subs.  Instead of having the DSP run 3 way out to channel 1, I would change it so channel 1 is sub out, and channel 2 is mains/tops out, which would be 2 way.  Then hook channel 2 out to L/R on the desk, and channel 1 (subs) to an aux.  Then I'm not using any of the onboard EQ for the L/R or aux on the desk, and letting the DSP do all of the crossover work.

I'll have to explore the M32 a bit to see if I am able to route these 2 separate sub signals to the same output.  If not, would I be able to use a XLR splitter to combine them?  I am wanting to combine them, as one of the options on the M32 is to make the Mono/Center Matrix dependent on the main L/R.  This way the subs come down proportionally with the main L/R.

To clarify, I use one DSP per side for larger shows, so I have the extra channel available and can still run a stereo mix for shows.

[Mac Kerr]

I understand what you mean about not wanting to add any additional high pass to the mains, and I do have processing already on the subs.

I guess the only option then would be to change the DSP output settings, and run a separate signal out just to the subs.  Instead of having the DSP run 3 way out to channel 1, I would change it so channel 1 is sub out, and channel 2 is mains/tops out, which would be 2 way.  Then hook channel 2 out to L/R on the desk, and channel 1 (subs) to an aux.  Then I'm not using any of the onboard EQ for the L/R or aux on the desk, and letting the DSP do all of the crossover work.

I'll have to explore the M32 a bit to see if I am able to route these 2 separate sub signals to the same output.  If not, would I be able to use a XLR splitter to combine them?  I am wanting to combine them, as one of the options on the M32 is to make the Mono/Center Matrix dependent on the main L/R.  This way the subs come down proportionally with the main L/R.

To clarify, I use one DSP per side for larger shows, so I have the extra channel available and can still run a stereo mix for shows.

Ok, stop, you are getting into the weeds. What are your speakers, both mains and subs. How are they amplified? What DSP are you talking about? How is it all wired? What 2 separate sub signals are you talking about? You need 3 outputs, Left, Right, and Subs. Left and right come out of the console main out, the subs feed comes out of whatever aux send you are using. Left and right go to your DSP just as they always did. If the DSP can do 3 in 3 out the subs feed can go to the 3rd DSP channel. If not, you can do a simple LP filter in the console and not use the DSP on the subs.

Much clearer information is needed to comment further.

Mac

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