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[Jordan Wolf]

Do you have any pictures of the spaces you're talking about?

Many of us are used to boardrooms, hotel ballrooms, arenas, and open fields/lots, so our context may not be in line with your room description.

That matrix mixer does seem to have a lot of capability in routing and mixing; if it's the right tool for the job, your client will be quite glad they spent their money. Gotta be able to hit those curveballs, right?

When I spoke to Dan Dugan, he steered me to the Yamaha MRX7-D, which apparently handles all these issues and returns the wanted benefits. Also allows for custom control UI to be delivered for the system via tablet, Crestron, etc. . .rather than a QL series control surface.

I'm currently investigating that device with Yamaha rep and another integrator and have been assured it's the business for this sort of application. Based on my research of the features, it would appear that it's what I need. It may not totally get the operator out of the picture, and there will be a camera operator in the room, as well, but it will alleviate their current situation of having a console in the front of the room. I certainly don't plan on a plug-n-pray install for the client


I should have added previously that they want to run 13 conference mics open, because folks have trouble remembering to unmute their mic before speaking. That's including a wireless lectern mic that may be located in front of the PA. Local PA is already installed and is adequate for the job (room could use some additional acoustic treatment). Client also wants an output for overflow area with separate PA which they will rent, as needed. Client is investigating adding a single Skype feed for call-in questions, as well.

I get that automixing isn't a panacea, but it seems like the best tool for managing 13 open mics in a conference room.

[John Roberts {JR}]

I've chatted with Jon Tatooles from Sound Devices regarding their AM implementation.  The 'Mix Assist' system was SoundDevices original AM implementation and was "dugan style" but not done in collaboration with Dan.  The Dugan Automix that is implemented in the new 688 is indeed a direct and blessed collaboration with Dan Dugan.  The Mix Assist system was also kept on board for those who may have preferred, or were more accustomed to, that method.

The HD668B is a value priced headphones from our friends at SuperLux.  I don't think it comes with any AM capability. 

Thanks for the correction,, I couldn't find it with google so ASSumed it was not in the market.

JR

[John Roberts {JR}]

I've heard that automixing has magical properties, just like a line array and I've always wanted to work with magic. . .

Not exactly magic, but the gain sharing algorithm that Dan Dugan came up with in the 60s(?) is very elegant at managing groups of similar open mics in a common space. It is so simple I will share how it works. 

-If there is one mic getting most of the signal it will get the same percentage (most) of the gain, all others will get turned down proportionately (so small input level gets almost no gain).

-If two mics are equally contributing the same level of signal, each will get turned down -3dB. The algorithm is even clever enough to turn down coherent (same) signals -6dB, while trimming incoherent (different ) signals -3dB.

-The overall effect is that gain is shared seamlessly, and background noise remains constant, because as far as the room is considered there is only the gain of one open mic, no matter how many are being shared proportionately.

Seriously, though, need to avoid feedback from local PA and additional remote PA (just outside the room), need a solid broadcast recorder feed, and need to use the prioritizing for the chairman of the meetings. Also, client would like to eliminate the current system's requirement of an operator in place during meetings.

A huge benefit from the Dugan algorithm is that the room behaves as if there is only one open mic, not the dozen or so that would cause a feedback nightmare.

Priority for one channel over the rest, on top of the gain-sharing is a feature of "some" AM. I got a patent back in 1997 for one such variable priority feature (used on first two channels of Peavey AM). The high end Dugan has per channel adjustable priority (I think). When properly executed this priority does not degrade the NOM feedback suppression.

I can not speak intelligently about which Dugan implementations have the full feature set, the priority is not part of the basic gain sharing algorithm that people call "Dugan style", but layered on top of it as an extra feature.   

This being a conference room application, it would seem that automixing is ideal for the situation. Had only seen it featured in consoles, so I brought the question to the live board because it's the home of good answers.

The Dugan gain sharing algorithm will be very useful for multiple mic applications and will get you 95% of the benefit (IMO). The priority feature is icing on the cake, nice but without it you still got cake.   

JR

PS: Note: Before Dan's patent expired (last century) there were multiple different AM strategies. Like the Mix Assist, and numerous others. For basic AM the Dugan algorithm is superior (IMO).

[drew gandy]

I agree that this should probably be in the installation forum.  But I'll make a couple comments here, and I am of course following John Robert’s current signature.  I’ll tell you what I think I know regardless of what you need to know.   

There are products from ClearOne, Biamp, Polycom, MediaMatrix, BSS, Lectrosonics, QSC and even perhaps Shure (SCM820) that are likely to meet your criteria.  And this is not a complete list; I know I’m forgetting a few.  Most of these have gain sharing AMs at least as an option and some of them are what are sometimes termed "free wire" systems where you can build crazy custom configurations.  The first 3 in my list tend to be the top dogs in conference rooms but some in the industry consider QSC to be ahead of the pack in terms of the brains behind them.  Some of the brilliant folks from Peak Audio (original designers of MediaMatrix) moved to QSC and are spearheading their products.  Q-Sys is definitely a different animal with some very powerful capabilities if you need them.  The Yamaha matrix mixer mentioned earlier looks like a formidable device and is obviously Yamaha's attack at the lucrative conference room installation market leveraging the heavy Dugan name.  I'm just trying to point out that Yamaha isn't the only game in town and it might be worth some time to look at some other options.  That said, for some of these systems you won't get far without working with a 'system integrator' (or whatever you want to call the people that design and sell these kinds of systems) as some of these products aren’t really available except to certified installers.

Most of us in live sound (and recording) consider the 'Dugan Style’ gain sharing to be superior to the gated systems on account of the smooth "artifact" free sound not to mention the elegance of the concept.  But there are situations where [intelligent] gated systems are preferred.  In fact, I'm rather impressed with some things that Shure's old IntelliMix does.  I'm even starting to ponder the suggestion that gain sharing is better when each participant gets their own mic (think a panel on TV where each has a lav) but that Shure's intelliMix (or something like it) might be better where participants are sharing mics or where some participants might wander away from their mic.  IntelliMix will open a mic when it is as little as 1db louder than the background noise (average of all the mics) and tries to only open one mic per “talker".  In these situations a plain gain sharing system will just give the loudest mics a small nudge such that most of the mics in the room are still "up" and contributing room sound.  Compare that to the Shure system where only one mic (probably the best one) will get max gain and the others will all be turned down 13-15db.  Exclusively turning on the mic with the best direct to reflected sound ratio can make a big difference in intelligibility even if it’s not really any louder than any other mic.  Another way to think about this is that gain sharing is great when there is a tech there to give it some help from time to time but a gating scheme might be better for completely autonomous systems.  And also consider the destination.  For a broadcast it might sound really bad if mics are audibly turning on and off but for a functional meeting where you're just trying to get clear enough audio to transcribe, it's not an issue.  As always, 'It Depends’ and I have not done clinical trials comparing the efficacy of the various mixing systems [yet].  I’m just speaking from my own experience and research. 

Lastly, for any sound system like this, you are at the mercy of the humans.  Someone who doesn't want to be heard, will not be heard.  And someone who thinks they are smarter/better/loud enough, will often thwart our efforts as well.  Sometimes they point their mic away from them (or even unplug them!) or they lean so far back away from the mic that they can't be picked up well or they will talk into the side of the mic or...  Others will use a mic when they remember but tend to forget as they get deeper into the conversation.  Often the best upgrade for a conference system is to upgrade the moderator so that they police microphone usage adequately. 

Double lastly, I just watched "War Machine" on Netflix.  There was an interesting scene in Berlin with a Q&A microphone.  I'm impressed at how well they captured a typical Q&A scenario.  I won't comment about the rest of the movie. 

[ProSoundWeb Community]