Fbs In The Stagescape

[treewiz]

How come the stagescape does'nt use the FBS in the monitor tweeking and only in the mains deep tweek where you really need it or does it? And if so how do you apply it? I am having a terrible time controlling feedback in the monitors.

[dboomer]

The feedback filters are set per input so that they are active in any/all outputs since all outputs contribute to the problem (unless they are isolated in different acoustic spaces).

 

Which firmware version are you using?

[treewiz]

1.10

[dboomer]

See post #22 in this thread.  http://line6.com/support/topic/1260-feedback-reduction-barely-working/page-2?do=findComment&comment=15440

[treewiz]

Thanks for your help and input, I'll see what I can acomplish with tweaking the system.

[velok]

Questions: If you have FBS on in the M20d mixer and are hooked up to your Line 6 mains (and/or monitors) via L6 Link.  Do you need to have the Feedback Suppression button set to "On" on your Line 6 speakers, e.g. L3m? 

 

What is the impact of having FBS on in the M20d and off in the speaker and vice versa? What is the impact of having both the mixer and the speakers' Feeback Supression set to "On"? 

 

In other words, how do the various permutations of "On" and "Off" for feedback suppression on the mixer and speakers interact between the M20d and the Line 6 speakers when they are linked via L6? 

[Digital-sound]

In another thread, dboomer recommends not using the FBS on the speaker if connected via L6 link.

 

However, I am also somewhat curious about the scenarios velok asks about.

[dboomer]

I would recommend using the feedback manager in the mixer only and not in the speakers in almost all situations.

 

The difference is that the mixer applies filters only to the input channel while in the speakers they are applied to all signal that goes through them. Either way there are 12 filters available but only one set for the speakers while 12 sets in the mixer are possible (XLR inputs). So it's possible that you could end up with 144 filters in the mixer (unlikely though :))

 

The filters themselves are not linked via L6 link.

[litesnsirens]

Now that makes total sense....It's funny that this last explanation is what finally made it click for me.

[Digital-sound]

Yes, it is very clear to me now too.

[velok]

Thanks for the info dboomer!  That definitely sheds some light on the subject. 

 

I would actually have expected the M20d to have enough intelligence built in so that it managed the FBS automatically on both the speaker and the mixer when an M20d mixer is attached to a Line 6 speaker via L6 Link.  It seems as if Line 6 could take better advantage of the digital L6 Link connection allowing more complex interactions and decision trees between the mixer and the speaker.  I am surprised that users even have to ask about this. 

 

Even if the thought was to give the user maximum flexibility I think a best practices implementation would be to have a default behavior.  For example, if a StageScape speaker is hooked up via L6 Link to an M20d, the default behavior should be for the speaker's FBS to be off to allow the M20d mixer to manage the FBS.  This is the optimal setup as per dboomer's post.  Then, if a user did not want the default behavior, but instead wanted to pick only the speaker FBS or both the speaker and the M20d's FBS, they would have the option (as they do now).  A firmware improvement might be that all three FBS setup scenarios should be available to be set from the M20d (with the best choice being the default) instead of having to check the setting on the speakers.  Even better would be for a smart system that knows and picks the best FBS settings automatically across all of the L6  components attached (but still has the option for a manual change).  Again, let's take better advantage of that digital link and useful and significant communication between the speaker and the M20d.

 

It seems like it would be an advantage to have the M20d intelligently manage the FBS on both the speakers and the mixer such that if there are some exotic scenarios where speaker or mixer FBS (or both) would be more preferable, this could be set automatically by the M20d rather than the user worrying about the best combination of FBS on separate components (mixer and speakers).  This also eliminates having to physically check the setting on every speaker and monitor.  You should be able to check this from the M20d.

 

Btw the three possible FBS scenarios I am referring to are:

1. M20d FBS on - speaker FBS on

2. Speaker FBS on - M20d FBS off

3. M20d FBS on - speaker FBS off

 

I see the advantage of applying a notch filter (FBS) only on the offending input instead of the entire speaker.  That way (depending where the notch occurs in the signal chain) you may only be impacting one instrument/mic (notching pre output at the mixer) rather that notching all inputs (notching at the speaker).  Big advantage!  I also see the benefit of having a set of twelve available filters for each channel (144 total)  vs. having a limit of 12.  Although if you ever need 144 notch filters you either have bigger problems or are probably running such a huge system that you are not using an M20d.

 

You did raise one question for me though.  I would have thought there would be situations where it is the cumulative impact of two or more channels interacting causing feedback.  It seems like in those cases having the "global" FBS on the speakers set might work better than having the FBS on individual channels on the M20d.  Don't know if my premise (two or more channels interacting to cause feedback) is correct, or perhaps this situation is so rare it is not worth worrying about in normal usage, but just curious.  Again, I would encourage Line 6 to have the system intelligently manage FBS across multiple components while still allowing the user to choose their own settings if need be. 

 

Argh, my brain is hurting.  Line 6, you have a badass digital system, please have it pick the best FBS settings for me.  I am a musician who wants to play and not tweak.  I think that is the largest target demographic for this mixer.  I spent a lot of money on Line 6 equipment so it can link up via L6.  Choose the best FBS settings and leave me some flexibility to change them if I don't like them.  You have all these smart digital components and the ability to leverage their capacity to communicate bi-directionally.  Why are they not talking to each other in the FBS realm?  Any thoughts?

[Digital-sound]

Interesting points. And a lot of thought put into it. But when I think about it, it seems the M20d is doing the best possible work with feedback. Why do the speaker if the board has the ability to do all the mics? Even if it means 10 out of 12 have the same frequency notched out? Still leaves two unaffected.

 

However, if we want to really think of unlikely situations, I guess if it notched the speaker when there were a majority of mics notched at the same frequency, it could release the mics, and they would have 12 frequencies available for being notched again. Does seem very unlikely. But I understand what you are thinking.....I think.